Thomas, this is another outstanding troubleshooting video. Your step-by-step troubleshooting process appears instinctive to you based on years of experience. You also recognize many viewers are not experienced, and thoughtfully explain the rationale behind the troubleshooting process in a way that helps us understand and learn. For example, near the beginning you discuss the significance of the upper radiator hose being cold instead of hot. You didn't just put your hand on the hose to determine this for your own benefit and make the repair. Instead, you discussed the significance of a cold hose while the instrument cluster shows an overheating condition and how this helped narrow down the issue to a temp sensor. This kind of step-by-step rational explanation is what I find most valuable about your videos. I cannot overstate how much your thoughtful narration is appreciated. Thank you.
Thank you for the kind words! Send me your mailing address and I will send some channel stickers your way. Ckick the fkh161 link in the description and then click on "tool request" to send me the info. Thank you for watching!
I had a similar problem, after watching this video, i bought a new temperature sensor and the issue was solved. Thank you so much Thomas, your videos are very helpful!!
Wow 256,000 miles . Nice to see a customer that pays attention to their car. What's the highest milage VW you have worked on. Just curious Thomas , what do you drive.
I think you may have caught that hose (brake booster/servo?) just in time! Would have affected braking and engine performance I guess, if it had come undone at speed!
Hi thomas.. would the best way to test a sensor being, by unplugging it at put it in hot water still connected to the car? Mine goes to 90 some days, some days it goes to 60 only 😂 some days it wont even move... i have changed the thermostat, and i have good flow all around.. it never "overheated" it just has a life of its own!
I have an A4 B6 2.4 V6 BDV, and changed temp sensor behind engine a couple of years back, from original black sensor.The reaaaly awkward one!! Recently throwing a high voltage temp sensor error code, but instrument cluster temp ok. Fan come on full, with cold engine. Are there two temp sensors? Is there another one on bottom rad hose? or just the one fault one that needs re-changing?
I'd have to check a wiring diagram. The green sensors go bad as well... even if only a couple years old. If your scan tool can view engine sensor data, view coolant temperature from cold till warm to see if there are any drop outs. If that sensor is ok, then there might be another. The sensor ID is usually within the code, G62 (or other).
Hi you mentioned timing plug at 5.09 on the video, do you know the part number for it? I searched for timing plug because mine is missing and cannot find it. I have a 2005 Gti 1.8t thank you.
Hello I have a 06 Audi A4 1.8 car running hot an building alotta pressure in top hose no heat is in the car either... car runs hot after 5 min of driving ... it all started when my thermostat housing broke on eway so I replaced that now car still runs hot
The car now having trouble to crank it building a lot of pressure before deciding to crank after about 7 tries an car still running hot even with thermostat out
@@javiangray944 As mentioned, no heat inside the car is probably due to a bad water pump. If the engine does not want to crank or cranks and then struggles to turn further, then you could have coolant in the cylinders (hydrolocking)... due to a bad head gasket... from the overheating... which blew the thermostat housing. With the thermostat removed, you can check the water pump impeller. Stick your finger in the thermostat opening (engine off) and check if the impeller is loose.
Hi Thomas, I have a 03 golf with the 1.8t and I noticed that my car will go up to 95c and sometimes to 99c but goes back to 90c is that normal temperature? And another question I check my oil level once a week and I noticed the I have milky stuff on my dipstick. I do have a catch can but is this normal? I dont have it on my oil cap though.. And the milky stuff only happens in the winter time. In the summer time I never see it
Normal temperature. If you only do short distance stop & go city driving, the milky stuff "could be" normal. Check your PCV system for leaks and correct operation (check valves). If the oil itself is milky... that's not good.
Hi Thomas, why does my temp gauge jump to the max all of a sudden, the coolant light comes on, the second vent kicks in, but the VCDS shows everything normal at about 200 degrees Fahrenheit? 1.8T AUM engine. I changed two CTS, made no difference. The problem comes totally randomly.
There are 2 circuits within the CTS... one feeds the dash, the other feeds the ECM. If the ECM is reading / showing normal, but the needle in the instrument cluster swings wildly... then the problem is with the circuit for the instrument cluster (doubtful that it's a sensor issue, if you have already changed it a couple of times). Have a close look at the harness plug for the sensor. Check for broken wires that could be touching. In order for the needle to go to max hot... "low resistance in the circuit" is needed. Follow the wiring loom as far as you can, looking for places where the wiring / loom could be rubbing against something (causing one wire to ground out or 2 wires to touch).
My 1.8t gti my coolant bottle upper return hose I believe it is broke so repaired it and I believe it has more flow through that could that be a reason why my coolant is boiling? Thank you for your time
More flow is better than not enough. Boiling how / when? What does your temperature gauge / needle show? What temperature does the ECM "see" when you check it with a scan tool? Any other issues besides "boiling"? No heat inside the car? Loss of coolant? Post a video on your channel so that I can see what you see.
@@EXOVCDS turns out head gasket,so i replaced it resurfaced. Runs really good. So. cal is really hot right now whats a normal operating temp with the ac on hot as f outside? Is 240 pushing it? really appreciate your knowledge.
@@Kevin-wy8kc I don't live in a hot climate... so I don't know what max temperature with AC would be. I would suspect the engine "should" be able to maintain something close to 190-200 with the AC on. 230 tops. Check / compare with another 1.8T VW owner.
So if thermostat is bad upper hose would be hot an lower would be cold? I have a issue with my b6 A4 1.8t, it over heats and no heat in cabin. It’s all happening after I did the timing belt and water pump, I flushed the coolant and put brand new coolant and heat stopped working at idle, than I replaced heater core, coolant flange, and expansion tank and cap, but after expansion tank and cap replaced, it over heats while I drive and heat gets weak or cold. My obd shows max 113c at highest temperature
Hi Thomas I.m having a bit of a head ache with Audi A4 fsi o4 plate I.v replaced the water pump twice now but I.m still not getting return to expansion tank I.v checked each time I.v replaced the pump to see if there is anything restriction but all clear any idea what it could be thankyou
Thomas EXOVCDS hi Thomas I.m bleeding the system first By filling the expansion tank slowly to iliminate bubbles I.m starting the engine and waiting for bubbles to start I.v tried pulling of top hose to matrix squeezing bottom and top hoses to help it circulate but just getting nothing bottom hose and top hose both getting hot won,t circulate defo no heat inside the car just can.t figure it out changed pump again for another one last night still no joy any help would be really appreciated also changed the temp controls cave at the back of the engine cheers mate for you replie and for your help ta
What's the engine production code? Size of engine? Is the pump belt driven under the intake manifold? Is the pump actually turning (leave the plastic cover off)? I was going to suggest filling coolant through the upper radiator hose... level in coolant reservoir will rise as coolant enters the system. Lower hose can usually NOT get hot if coolant isn't circulating. No heat inside the car does point towards no circulation, unless it is due to an air pocket. Let me look at some engine details once I know which engine you have.
Mine is doing it the top hose is hot lower is warm.. I see flow going into reservoir.. no steam or leaks.. I hope this fix this problem I have.. 04 Jetta gli turbo 6 speed
A scan tool can view engine data... from what I hear, a lot of parts stored scan / check for free. Sensor isn't that expensive and it's easy to change. If it still happens with a new sensor... I would advise to not drive it long (just in case). How quickly does it get to the hot / overheating position (3/4)?
@@aaronbrown1868 If it were overheating due to a bad thermostat... it would warm up quicker and the lower hose would stay cold. If it were overheating due to a bad water pump, you'd have no heat inside the car, no flow and lower hose would stay coldish. Let me know if the sensor makes a difference!
So far I put the new sensor in and let it cool completely down.. just drove 5/6 miles and bam the sensor hasn't moved so tomm when I drive it I'll let you know if it worked
hi thomas. i have overheating issue. My engine is Auq. It never goes up 90 celcius degree. But now going to 130 degree which is limit and red light flashing with buzzer sound. I checked radiator hoses and i realised upper one very hot and down hose very cold. And my fans doesnt working. When i open air condition fans turns. I think my thermostat stuck closed. What do you think ?? Oil good, coolant fluid is normal.
Hey thomas i'm very confused on whats happening to my car. 2006 audi A4 2.0t. Had a coolant leak. Infamous coolant flange. Yay changed that and i took off my intake. Manifold to carbon clean. Car starts. Drive fine. But now it wants to overheat. Thermostat, waterpump, new 1 year ago. Cooling fans turn on. I have heat in the car. Not sure if i bled the system correctly but at idle is fine once rolling for a few minutes it wants to overheat sl i shut it off immediately. Then wait to cool down and continue driving. I'm lost🤷♂️
If you didn't have that issue before... possibly an air pocket still in the cooling system. Further bleeding or hot & cold cycles will help get the air out. By hot & cold cycles I mean running the engine till the thermostat opens, shutting the engine off, let cool off til cold, start again and repeat. Top up coolant level if level drops. Confirm with scan tool that the ECM is seeing the same overheating temperature as the dash is showing. If temperatures are different, replace the temperature sensor.
@@EXOVCDS speaking of CTS i do have an aftermarket one. Not oem. I HAVE vagcom can you please tell me the measuring block go check? Also what temp should my car be in once warmed up?
Vagcom will have it listed as coolant temperature 001 or 002... just go through the blocks until you see it. Then do the same in the instrument cluster control unit... the readings should be similar. 98c to 105c is average warm running on all makes & models.
If you have no heat inside the car, then the water pump is bad. If heat is intermittent (depending on rpm), then you have an air pocket or low coolant level.
aaa aa That is the vacuum feed to the brake booster... when the hose breaks, you will have a stiff brake pedal (no assist from the booster). Engine vacuum pulls on the booster diaphragm, which makes it easy to press the brake pedal once the engine is running.
Visual inspection around the engine... if you don't see any coolant leaking / dripping from the engine, check the EGR cooler. You can bypass the cooler and then monitor if the coolant is still being used more than normal.
Hi iv a 07 jetta and i got the water pump done last year and now its useing loads of water but my heaters are working and its not over heating what could be wrong please reply to let me no or anyone else thank you
Marcin Wojciechowski Sorry... I bought 6 from Home Depot. www.energizer.com/SiteCollectionImages/Flashlights%20and%20Lighting/Flashlights/Flashlight/tab1-preparedness-rechargeable-led.png
Hi Thomas, I have a mk4 1.8t overheating issue. The fans only run when the coolant temp reaches 110c. Does this mean that stage 1 isn't coming on? I replaced the thermoswitch already. I appreciate your help!
Hey Thomas, my 2001 jetta 1.8t is overheating the fans won't turn on and that bottom hose you mentioned is cold and the top one was hot... what's messed up and what do I need to replace please reply this is my only car and I go to work and school almost everyday!!!
Alex Gutierrez stuck closed thermostat or a bad water pump. If you have heat inside the car, then the water pump is ok... replace the thermostat. No heat inside the car = bad water pump. Replace the water pump (timing belt & pump kit).
Thomas EXOVCDS it does not get cold does that mean it's just the thermostat? I was told there could be an air pocket in my coolant system, I drained it and it still overheats
I own a Audi A4 B6 1.8T I recently had an overheating problem, they told me it was the clogged cats, changed that but still over heated, so moved to change a small busted hose going to the thermostat, still over heated, moved on to changing the thermostat still overheating, it still has my needle moving to the red and my dash still shows low coolant which I have topped off several times, no signs of leaking fluids. At this point I think my cooling system could possibly be clogged but I don't want t o keep playing the guessing game. Any advise?
+OG BUSINESS GROUP If the coolant level continues to drop... it is dropping because you have a leak somewhere or because the engine is overheating and the reservoir cap is "venting" the pressure / coolant. If you have a leak, the engine should NOT overheat, even if there is very little coolant in the reservoir. However, the coolant level warning light will be / should be ON. If you do not have any leaks and you have already changed the thermostat, then you either have air in the system (not fully bled out), a head gasket issue (compression gasses getting into the cooling system / coolant entering the combustion chamber) or your water pump is broken (not circulating the coolant). If the water pump is the cause, you should be noticing lack of heat inside the vehicle when turning the climate controls to max heat & blower to max. A faulty water pump will not be able to supply the inside of the vehicle with hot coolant and thus the heat output inside the vehicle decreases. Have a shop (that is familiar with VW / Audi look at your vehicle... sounds like whoever has already, is not familiar with the engine.
Thanks for the video help Thomas, you make the job look so easy every time. I am working on a 2001 passat 1.8t I have replaced water outlet, thermostat, radiator, water pump and flushed the cooling system and I cannot get heat out of the vents. Neither heater hose gets warm so I have no more ideas. Anything would help. Thank you again.
Disconnect the heater core hoses and verify that you have good flow out of one of the hoses (the feed to the core) when the engine is reved up (may need a second person so that you can monitor the hoses). If you have good flow out of one of the hoses... attach that hose to the core. The core does not have any "flow control valves", meaning that if you connect the hose and you do not get any flow OUT of the core, then the core is plugged and needs to be replaced. =( Let me know what your test reveals.
@@cynthiaharris8559 i have a partial video that i recorded... based on this video: th-cam.com/video/J40bceY8mF0/w-d-xo.html watch this one and let me know if you have any questions.
Verify thermostat opening (lower radiator hose should get warm when the engine reaches around 97c overall temperature). What was the original reason for thermostat replacement? Same reason?
How quickly does the needle rise? Measure / check actual temperature with a scan tool or with an infrared heat gun (upper radiator hose). I have seen several cases where the temperature sensor was defective.
tino2005gti Thanks for watching! I'm far from amazing... I just happen to share what I do, there are many more knowledgeable mechanics than myself out there (maybe even in your area).
How hot did it get? Does the starter "click"? Can you turn the engine over by hand (wrench or socket on the crank pulley)? Worst case... engine seized-up.
Thomas EXOVCDS yes the starter dose click.the engine turns over but feels heavy haven't tried it by hand yet and also it sounds like there's a click coming from the head
+Matt Parra Not good... but you'll have to check it out further to be sure it's not just a weak battery. Smell the oil... check for oil in the coolant or coolant in the oil. If you have no luck, pay a shop 1hr to look at it / for a diagnosis.
The Coolant Fan Control Module is located under the battery... mounted to the chassis. Low speed fan operation DOES NOT go through the fan module. If low speed is not coming on... it is NOT a fan module issue.
Thomas, this is another outstanding troubleshooting video. Your step-by-step troubleshooting process appears instinctive to you based on years of experience. You also recognize many viewers are not experienced, and thoughtfully explain the rationale behind the troubleshooting process in a way that helps us understand and learn. For example, near the beginning you discuss the significance of the upper radiator hose being cold instead of hot. You didn't just put your hand on the hose to determine this for your own benefit and make the repair. Instead, you discussed the significance of a cold hose while the instrument cluster shows an overheating condition and how this helped narrow down the issue to a temp sensor. This kind of step-by-step rational explanation is what I find most valuable about your videos. I cannot overstate how much your thoughtful narration is appreciated. Thank you.
Thank you for the kind words! Send me your mailing address and I will send some channel stickers your way. Ckick the fkh161 link in the description and then click on "tool request" to send me the info. Thank you for watching!
I had a similar problem, after watching this video, i bought a new temperature sensor and the issue was solved. Thank you so much Thomas, your videos are very helpful!!
Thank you for sharing your DIY experience / feedback... and thank you for watching!
Wow 256,000 miles . Nice to see a customer that pays attention to their car. What's the highest milage VW you have worked on. Just curious Thomas , what do you drive.
Steve Rob Kilometers... I think the highest kilometer car that I have seen, was around 400k- 450k km's. I drive an old BMW with 250k km's.
I thought the cars in USA were in miles. You must have a lot of canadian cars down there.
Steve Rob In the USA yes, I'm in Canada.
I thought you were Merican. Where in Canada.
Steve Rob West Coast.
Nice work as always Thomas. Hopefully, the customer will get that fan motor replaced.
Thank you Thomas I really appreciate it take care buddy.
I think you may have caught that hose (brake booster/servo?) just in time! Would have affected braking and engine performance I guess, if it had come undone at speed!
Sometimes I get lucky.
Hi thomas.. would the best way to test a sensor being, by unplugging it at put it in hot water still connected to the car? Mine goes to 90 some days, some days it goes to 60 only 😂 some days it wont even move... i have changed the thermostat, and i have good flow all around.. it never "overheated" it just has a life of its own!
Most likely a sensor issue (dropping out).. I was gonna say thermostat, but since that has already been done, time for a new sensor.
Thomas EXOVCDS thank you for your reply! Im a big fan of your work! Keep up the videos, i watch them all! 👆
Thank you, let me know how it goes.
I have an A4 B6 2.4 V6 BDV, and changed temp sensor behind engine a couple of years back, from original black sensor.The reaaaly awkward one!! Recently throwing a high voltage temp sensor error code, but instrument cluster temp ok. Fan come on full, with cold engine. Are there two temp sensors? Is there another one on bottom rad hose? or just the one fault one that needs re-changing?
I'd have to check a wiring diagram. The green sensors go bad as well... even if only a couple years old. If your scan tool can view engine sensor data, view coolant temperature from cold till warm to see if there are any drop outs. If that sensor is ok, then there might be another. The sensor ID is usually within the code, G62 (or other).
Hi you mentioned timing plug at 5.09 on the video, do you know the part number for it? I searched for timing plug because mine is missing and cannot find it. I have a 2005 Gti 1.8t thank you.
For 5 spd transmissions:
www.ecstuning.com/b-genuine-volkswagen-audi-parts/transmission-bell-housing-timing-inspection-plug/02a301115a/
Hello I have a 06 Audi A4 1.8 car running hot an building alotta pressure in top hose no heat is in the car either... car runs hot after 5 min of driving ... it all started when my thermostat housing broke on eway so I replaced that now car still runs hot
The thermostat housing probably broke because the water pump is broken.... bad water pump = no heat inside the car.
The car now having trouble to crank it building a lot of pressure before deciding to crank after about 7 tries an car still running hot even with thermostat out
Fans cut on late after I turned the car off
@@javiangray944 As mentioned, no heat inside the car is probably due to a bad water pump. If the engine does not want to crank or cranks and then struggles to turn further, then you could have coolant in the cylinders (hydrolocking)... due to a bad head gasket... from the overheating... which blew the thermostat housing. With the thermostat removed, you can check the water pump impeller. Stick your finger in the thermostat opening (engine off) and check if the impeller is loose.
these video help me out so much
Nice to hear... thank you very much! Thank you for watching!
yeah no problem! thanks for the great content, keep it coming!
Hi Thomas, I have a 03 golf with the 1.8t and I noticed that my car will go up to 95c and sometimes to 99c but goes back to 90c is that normal temperature? And another question I check my oil level once a week and I noticed the I have milky stuff on my dipstick. I do have a catch can but is this normal? I dont have it on my oil cap though.. And the milky stuff only happens in the winter time. In the summer time I never see it
Normal temperature.
If you only do short distance stop & go city driving, the milky stuff "could be" normal. Check your PCV system for leaks and correct operation (check valves). If the oil itself is milky... that's not good.
@@EXOVCDS thank you I will check my pcv valve today
Hi Thomas, why does my temp gauge jump to the max all of a sudden, the coolant light comes on, the second vent kicks in, but the VCDS shows everything normal at about 200 degrees Fahrenheit? 1.8T AUM engine. I changed two CTS, made no difference. The problem comes totally randomly.
There are 2 circuits within the CTS... one feeds the dash, the other feeds the ECM. If the ECM is reading / showing normal, but the needle in the instrument cluster swings wildly... then the problem is with the circuit for the instrument cluster (doubtful that it's a sensor issue, if you have already changed it a couple of times). Have a close look at the harness plug for the sensor. Check for broken wires that could be touching. In order for the needle to go to max hot... "low resistance in the circuit" is needed. Follow the wiring loom as far as you can, looking for places where the wiring / loom could be rubbing against something (causing one wire to ground out or 2 wires to touch).
My 1.8t gti my coolant bottle upper return hose I believe it is broke so repaired it and I believe it has more flow through that could that be a reason why my coolant is boiling? Thank you for your time
More flow is better than not enough. Boiling how / when? What does your temperature gauge / needle show? What temperature does the ECM "see" when you check it with a scan tool? Any other issues besides "boiling"? No heat inside the car? Loss of coolant? Post a video on your channel so that I can see what you see.
@@EXOVCDS turns out head gasket,so i replaced it resurfaced. Runs really good. So. cal is really hot right now whats a normal operating temp with the ac on hot as f outside? Is 240 pushing it?
really appreciate your knowledge.
@@Kevin-wy8kc I don't live in a hot climate... so I don't know what max temperature with AC would be. I would suspect the engine "should" be able to maintain something close to 190-200 with the AC on. 230 tops. Check / compare with another 1.8T VW owner.
@@EXOVCDS ok will do thanks!!!!!
So if thermostat is bad upper hose would be hot an lower would be cold?
I have a issue with my b6 A4 1.8t, it over heats and no heat in cabin. It’s all happening after I did the timing belt and water pump, I flushed the coolant and put brand new coolant and heat stopped working at idle, than I replaced heater core, coolant flange, and expansion tank and cap, but after expansion tank and cap replaced, it over heats while I drive and heat gets weak or cold. My obd shows max 113c at highest temperature
Air in the system... bleed it some more / correctly / fully.
Thomas EXOVCDS
Alright, but how? Keep the cap off and rev it?
@@wafi3187 Are you also bleeding at the heater core hose? Yes higher rpm to keep the flow pumping... but keep an eye on temperature!
Thomas EXOVCDS
Yes I did bleed from heater core hose, and if I keep the rpm up it over flows, but I will try that tomorrow
Thomas EXOVCDS
Also it says it over heat but no steam though and the radiator fan comes on at around 100c,
What would your next step be if temp sensor didnt fix this problem? I'm having this issue in my mark 4 1.8t
Watch this and tell me what your results are.
th-cam.com/video/LiDRUWPw_f4/w-d-xo.html
Hi Thomas I.m having a bit of a head ache with Audi A4 fsi o4 plate I.v replaced the water pump twice now but I.m still not getting return to expansion tank I.v checked each time I.v replaced the pump to see if there is anything restriction but all clear any idea what it could be thankyou
Is the engine overheating?
How are you bleeding the system?
Thomas EXOVCDS hi Thomas I.m bleeding the system first By filling the expansion tank slowly to iliminate bubbles I.m starting the engine and waiting for bubbles to start I.v tried pulling of top hose to matrix squeezing bottom and top hoses to help it circulate but just getting nothing bottom hose and top hose both getting hot won,t circulate defo no heat inside the car just can.t figure it out changed pump again for another one last night still no joy any help would be really appreciated also changed the temp controls cave at the back of the engine cheers mate for you replie and for your help ta
What's the engine production code? Size of engine? Is the pump belt driven under the intake manifold? Is the pump actually turning (leave the plastic cover off)? I was going to suggest filling coolant through the upper radiator hose... level in coolant reservoir will rise as coolant enters the system. Lower hose can usually NOT get hot if coolant isn't circulating. No heat inside the car does point towards no circulation, unless it is due to an air pocket. Let me look at some engine details once I know which engine you have.
Mine is doing it the top hose is hot lower is warm.. I see flow going into reservoir.. no steam or leaks.. I hope this fix this problem I have.. 04 Jetta gli turbo 6 speed
A scan tool can view engine data... from what I hear, a lot of parts stored scan / check for free. Sensor isn't that expensive and it's easy to change. If it still happens with a new sensor... I would advise to not drive it long (just in case). How quickly does it get to the hot / overheating position (3/4)?
I'd say after 30 minutes of sitting or driving.. no signs of overheating
Lower hose warm top hot
@@aaronbrown1868 If it were overheating due to a bad thermostat... it would warm up quicker and the lower hose would stay cold. If it were overheating due to a bad water pump, you'd have no heat inside the car, no flow and lower hose would stay coldish. Let me know if the sensor makes a difference!
So far I put the new sensor in and let it cool completely down.. just drove 5/6 miles and bam the sensor hasn't moved so tomm when I drive it I'll let you know if it worked
hi thomas. i have overheating issue. My engine is Auq. It never goes up 90 celcius degree. But now going to 130 degree which is limit and red light flashing with buzzer sound. I checked radiator hoses and i realised upper one very hot and down hose very cold. And my fans doesnt working. When i open air condition fans turns. I think my thermostat stuck closed. What do you think ?? Oil good, coolant fluid is normal.
Atakan Şenyurt Do you have heat inside the car? If yes then thermostat is stuck closed... If no heat inside the car, then water pump is bad.
Thomas EXOVCDS there is no heat inside car. How can i find out is it working or not without removing water pump
Atakan Şenyurt Watch this... 2.0l engine but the same test applies to your engine.
th-cam.com/video/ZcoT1oFr74g/w-d-xo.html
Thomas EXOVCDS i tested. Unplugged upper hose coolant fluid bottle and i started engine. Nothing come out. I think waterpump gone..
Atakan Şenyurt blow into the hose to make sure it is not plugged. If it's not plugged, then the water pump is bad.
hi Thomas I have a jetta 1.8 t 2002 .what is the normal engine temp range for this car.on obd scan it shows between 95 98.the fan starts on 96-97
That's fine... usually a little warmer (even though the needle in the dash shows 90c when warm).
Hey thomas i'm very confused on whats happening to my car. 2006 audi A4 2.0t. Had a coolant leak. Infamous coolant flange. Yay changed that and i took off my intake. Manifold to carbon clean. Car starts. Drive fine. But now it wants to overheat. Thermostat, waterpump, new 1 year ago. Cooling fans turn on. I have heat in the car. Not sure if i bled the system correctly but at idle is fine once rolling for a few minutes it wants to overheat sl i shut it off immediately. Then wait to cool down and continue driving. I'm lost🤷♂️
If you didn't have that issue before... possibly an air pocket still in the cooling system. Further bleeding or hot & cold cycles will help get the air out. By hot & cold cycles I mean running the engine till the thermostat opens, shutting the engine off, let cool off til cold, start again and repeat. Top up coolant level if level drops. Confirm with scan tool that the ECM is seeing the same overheating temperature as the dash is showing. If temperatures are different, replace the temperature sensor.
@@EXOVCDS speaking of CTS i do have an aftermarket one. Not oem. I HAVE vagcom can you please tell me the measuring block go check? Also what temp should my car be in once warmed up?
Vagcom will have it listed as coolant temperature 001 or 002... just go through the blocks until you see it. Then do the same in the instrument cluster control unit... the readings should be similar. 98c to 105c is average warm running on all makes & models.
@@EXOVCDS saw it. Temp came to 120 so it is overheating. Not a temp sensor issue. I think i need to re bleed the whole system.
Ok what about the heat it was coming out or not from the fans inside the car
If you have no heat inside the car, then the water pump is bad. If heat is intermittent (depending on rpm), then you have an air pocket or low coolant level.
hi Thomas i have tt 2000 model, and the speedometer needle just stop working.
Is the odometer still counting?
Hi, what function of that hose is?only know, that is coming from a boost brake... :)
aaa aa That is the vacuum feed to the brake booster... when the hose breaks, you will have a stiff brake pedal (no assist from the booster). Engine vacuum pulls on the booster diaphragm, which makes it easy to press the brake pedal once the engine is running.
Thank you much
I checked oil but its not differant and how do i check that coolant is leeking
Visual inspection around the engine... if you don't see any coolant leaking / dripping from the engine, check the EGR cooler. You can bypass the cooler and then monitor if the coolant is still being used more than normal.
Hi iv a 07 jetta and i got the water pump done last year and now its useing loads of water but my heaters are working and its not over heating what could be wrong please reply to let me no or anyone else thank you
What engine? Look for a coolant leak.
Hey, nice flashlight - what model is it?
Marcin Wojciechowski The hood light?
th-cam.com/video/OvLP9ISYaoI/w-d-xo.html
www.amazon.com/Snap-On-Work-Light-LED/dp/B00H5GRL3Q
***** No,no...the one you holds in your hand (white) - which looks like a shampoo bottle ;)
It gives nice sharp and focused light.
Marcin Wojciechowski Sorry... I bought 6 from Home Depot.
www.energizer.com/SiteCollectionImages/Flashlights%20and%20Lighting/Flashlights/Flashlight/tab1-preparedness-rechargeable-led.png
where is the fan relays and how many r there
Year, make, model engine?
Hi Thomas, I have a mk4 1.8t overheating issue. The fans only run when the coolant temp reaches 110c. Does this mean that stage 1 isn't coming on? I replaced the thermoswitch already. I appreciate your help!
Do you have heat inside the car?
Sorry... one more. Does it overheat while at cruising speed?
Thx for the super quick response! I do have heat, and it doesn't overheat while cruising, it only happens when stuck in idle traffic.
Follow these steps and tell me what you find.
th-cam.com/video/Roh6RCs8IJk/w-d-xo.html
I have a 03 a4 I replaced the head gasket and the thermostat and still is overheating any ideas ?
Air trapped in the engine?
Do you have heat inside the car?
Hey Thomas, my 2001 jetta 1.8t is overheating the fans won't turn on and that bottom hose you mentioned is cold and the top one was hot... what's messed up and what do I need to replace please reply this is my only car and I go to work and school almost everyday!!!
Alex Gutierrez stuck closed thermostat or a bad water pump. If you have heat inside the car, then the water pump is ok... replace the thermostat. No heat inside the car = bad water pump. Replace the water pump (timing belt & pump kit).
Alex Gutierrez th-cam.com/video/HjL9P5cZw6g/w-d-xo.html
Thomas EXOVCDS by heat inside do you mean the ac heater? Bc that works
Yes... if you have heat inside the car, then the water pump is ok (turn heater on max hot & blower motor on high... heat should NOT get cold).
Thomas EXOVCDS it does not get cold does that mean it's just the thermostat? I was told there could be an air pocket in my coolant system, I drained it and it still overheats
I own a Audi A4 B6 1.8T I recently had an overheating problem, they told me it was the clogged cats, changed that but still over heated, so moved to change a small busted hose going to the thermostat, still over heated, moved on to changing the thermostat still overheating, it still has my needle moving to the red and my dash still shows low coolant which I have topped off several times, no signs of leaking fluids. At this point I think my cooling system could possibly be clogged but I don't want t o keep playing the guessing game. Any advise?
+OG BUSINESS GROUP If the coolant level continues to drop... it is dropping because you have a leak somewhere or because the engine is overheating and the reservoir cap is "venting" the pressure / coolant. If you have a leak, the engine should NOT overheat, even if there is very little coolant in the reservoir. However, the coolant level warning light will be / should be ON.
If you do not have any leaks and you have already changed the thermostat, then you either have air in the system (not fully bled out), a head gasket issue (compression gasses getting into the cooling system / coolant entering the combustion chamber) or your water pump is broken (not circulating the coolant).
If the water pump is the cause, you should be noticing lack of heat inside the vehicle when turning the climate controls to max heat & blower to max. A faulty water pump will not be able to supply the inside of the vehicle with hot coolant and thus the heat output inside the vehicle decreases.
Have a shop (that is familiar with VW / Audi look at your vehicle... sounds like whoever has already, is not familiar with the engine.
***** Thank you, great feedback!
+OG BUSINESS GROUP Did you ever find out what was wrong? Mine is doing the same thing.
Thanks for the video help Thomas, you make the job look so easy every time. I am working on a 2001 passat 1.8t I have replaced water outlet, thermostat, radiator, water pump and flushed the cooling system and I cannot get heat out of the vents. Neither heater hose gets warm so I have no more ideas. Anything would help. Thank you again.
Disconnect the heater core hoses and verify that you have good flow out of one of the hoses (the feed to the core) when the engine is reved up (may need a second person so that you can monitor the hoses). If you have good flow out of one of the hoses... attach that hose to the core. The core does not have any "flow control valves", meaning that if you connect the hose and you do not get any flow OUT of the core, then the core is plugged and needs to be replaced. =(
Let me know what your test reveals.
@@EXOVCDS It's clogged. Do you have a video on replacing the heater core?
@@cynthiaharris8559 i have a partial video that i recorded... based on this video:
th-cam.com/video/J40bceY8mF0/w-d-xo.html watch this one and let me know if you have any questions.
My 1.8 has been overheating I changed the thermostat and it doesn’t seem like my water pump is going out but the car overheats at cruising speeds
Did you bleed the air out of the cooling system correctly? Do you have heat inside the car? No heat inside the car = bad water pump.
There is heat inside the car and i was planning on doing that today, thanks for the quick reply
Verify thermostat opening (lower radiator hose should get warm when the engine reaches around 97c overall temperature). What was the original reason for thermostat replacement? Same reason?
Yeah it was overheating and thats the first thing I changed and it was bad but it still says it’s overheating but i never get any steam or anything
How quickly does the needle rise? Measure / check actual temperature with a scan tool or with an infrared heat gun (upper radiator hose). I have seen several cases where the temperature sensor was defective.
Thomas are you located in Canada?
SonOfTamriel ...maybe.
Man, I'm glad glad to be subscribed to your channel...your an amazing mechanic...thanks to you I can do this stuff to my mk4 1.8t gti👍
tino2005gti Thanks for watching! I'm far from amazing... I just happen to share what I do, there are many more knowledgeable mechanics than myself out there (maybe even in your area).
hi tomas my 2002 audi a4 1.8t overheated and turned off and now the motor wont turn over what could it be thanks..
How hot did it get? Does the starter "click"? Can you turn the engine over by hand (wrench or socket on the crank pulley)? Worst case... engine seized-up.
Thomas EXOVCDS yes the starter dose click.the engine turns over but feels heavy haven't tried it by hand yet and also it sounds like there's a click coming from the head
+Matt Parra Not good... but you'll have to check it out further to be sure it's not just a weak battery. Smell the oil... check for oil in the coolant or coolant in the oil. If you have no luck, pay a shop 1hr to look at it / for a diagnosis.
Thomas EXOVCDS thanks will do!
ok thank u sorry if u see the same comment cause it tells me that message is not going thru
What's the actual problem with your car? Overheating? When? At idle only? Also when driving? Do you have heat inside the car?
2001 jetta 2.0 5spd
The Coolant Fan Control Module is located under the battery... mounted to the chassis.
Low speed fan operation DOES NOT go through the fan module.
If low speed is not coming on... it is NOT a fan module issue.
Here's a pdf for a Golf... same system as on your car: fkh161.ca/VW/AEG/AEGcooling.pdf
Its 1.9 tdi sport
If there are no coolant leaks, then the coolant is possibly leaking into the engine / exhaust via the EGR cooler.
Junk= VW! Buyer beware
LOL... probably bought it cheap and now you're complaining about having to fix a 20+ year old car.
@@EXOVCDS first off Scotty Kilmer will tell you the same thing They are complete junk! I’ll take his word for it! He should know!