2005 Jeep Liberty 3.7L P0300 Multiple Cylinder Misfire (ignition coils, shorted secondary windings)
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- เผยแพร่เมื่อ 14 ม.ค. 2017
- 05 jeep liberty with a 3.7l engine, customer complaint is a flashing check engine light, rough running. p0300 multiple cylinder misfire trouble code stored
In this video I will show you how to identify multiple cyl misfires using misfire counters on a snap on verus and how to verify multiple cyl misfires using a cylinder drop test on a coil over plug ignition design, and last but not least how to identify a shorted secondary winding in an ignition coil using a low amp clamp and the verus scope, I hope you enjoy thanks for watching. - ยานยนต์และพาหนะ
I had misfire on cyl 1 ,4 and 6 and replaced all coils with new ones from Ebay ,also put all new copper spark plugs and still had misfire on those cylinders ! The only thing left to replace or repair were the Fuel Injectors ! I put in some Chevron Techron Concentrate Plus Injector cleaner with at least 15 gallons in the tank and almost instantly my engine started sounding better and my Engine Light went out,no More Misfires yet with around 100 miles on it . Anyone with Misfire's on these engines might want to try some of that Type of Injector cleaner first and then if still having problems .start testing the coils ! Also check if your Radiator Fluid Plastic tank is leaking on to your two back 4 and 6 coils which can cause misfires which you either replace the tank or make your own shield that deflects any small amount of fluid down the side of the engine instead of on to your coils and plugs !
Thanks for the tip
That happened to me on my old Ford Jeep Liberty my four and six cylinder had antifreeze dripping out of the overflow onto those two cylinders and I caught it and change the the overflow tank. But now I have a po300 code and I bet it is those two cylinders and ignition coils that's no good but thank you for the tips. PS if you can remember where did you get your ignition coils from, I know on eBay but how much were they? If you can remember
@@mattlonproctor7221 you can buy some on ebay but I'm not sure which ones are better. Some of those new ones go bad too and can really mess with your mind thinking there must be a problem somewhere else. It happened to me with new ones from Ebay, a few went bad within days so I tested them with a multimeter and confirmed they went bad. Best thing to do is test the Coils when you get them to know the starting resistance numbers. If they change too much you will start to get misfiring again. I actually reused some of my old factory coils IF the resistance numbers were close enough to the new ones. That helped me out lots so I didn't have to send back in the new ones for replacement. If you buy cheap new ones, just pray they don't go bad. I think factory oem ones are the way to go if you are ok paying the extra money. There is no guarantee those will all stay within specs though too. IF only there was better quality control for electronic parts we wouldn't have these problems. Good luck.
My 03 Jeep liberty would run great when first started then after driving a bit would randomly start flashing engine light. Code was p0300. Turned out to be the MAP sensor. I removed it and cleaned it with Map sensor cleaner and re installed. Sensor was filthy inside! Started running better immediately and code went away. Keep in mind my jeep has 239k miles.
Very good diagnosis, never fully trust a scan tool, back up all tests, awesome video, thanks for showing a good coil pattern.
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Professional text book diagnosis. Love that! Keep doing what you do man. Thanks for sharing your time with us,
I have a 2006 Laredo 3.7L, it looks like the same engine.
The check engine light occasionally comes on and goes off.
I scanned a P0302 - cylinder 2 misfire.
This video helped a lot.
Maybe I will just check the plug before I go buying an ignition coil.
Thanks for the video and info!
Awesome visual ,clear process, easy to follow.helped me isolate my problem for my next project
i have same problem same year and model , i thought is catalytic convertor ,,thank you i fix my jeep for 10 dollars only.
I diagnosed my 2011 Jeep Liberty after the same warnings; P0304 in my case; changed coils, plugs, wires, etc etc. Turned out to be the fuel injectors! A little more difficult to put on than spark plugs, but not much more; and Amazon had a set that fell around $15 each! Try replacing them before taking it to the dealership. There is a good video on TH-cam regarding the 3.7L Jeep engines. Always good to check the electrical components while you are at it as well.
Great video man keep them coming!!
Simply but with a lot of info and easy to understand.
will do thanks for supporting
Awesome video. I think you've pointed me in the right direction.
Great video brother! Wish more TH-cam video's were done like this one. Keep them coming! Wrench on!
Great work good to see your channel growing. Cheers!!
Nice video & diagnosis Tom!
love your videos. keep them coming. they are short and to the point yet still give a ton of information
Thanks for the support Nick!!
Very informative video! Thank you very much!!!
Thanks very much for this video. Very helpful. I have an 05 liberty that is showing both a P0300 and a P0304 code. I plan on replacing all the coils anyway since the engine has about 150k miles and the coils it has are original OEM units.
Al final resolviste el problema
excellent job lecturer, i'm following.
Wish there was an easy way to find a local mechanic that would do the same sort of diagnosis on a vehicle. I wouldn't mind paying $100 an hour if they could get me down to just the actual parts I need. To many mechanics use the replace parts till it works strategy which just wastes money.
Just saw this post. Very common cause caused by a shorted Air Fuel Ratio Sensor . These vehicle uses a Air Fuel Ratio Sensor in place of a O2 Sensor. Find the faulty Air Fuel Ratio Sensor in either bank 1 or bank 2. Lambda in a Fuel Ratio Sensor should be 1. Voltage on Sensor should be 3.Volts if sensor is working properly. If heated circuit is not working computer will cause a lean condition affecting "all" cylinders in the bank . Computer sometimes will not show AF Ratio sensor code. Hope this helps. For all you that don't know how a air fuel ratio sensor works please TH-cam Air Fuel Ratio Sensor. Regards, Atech311
Good video keep em coming
Great job Tom ☺🔧🚘
Very helpful. Well done 👍
Very nice. It was a good video showing a subtle short in the pattern. Untrained guys would miss that.
Absolutely. Analyzing ignition can be a pain
Person most have bin driving around with single cylinder misfire, but when second coil went south vehicle will barely move, I am sure it will be coming back with a cat code very soon ! good video
Cat code? Do you mean catalytic converter? And why would it do that? I am curious as I have just replaced all my spark plugs and 02 sensors on my KK, reset the ECU and still have a P0420 "catalyst system efficiency below threshold (bank 1)" code coming up on mine.
nice
keep the diag vids going
anyone can do the other repairs.
A hybrid video would be cool
Great job.
Dude!! Thanks you
I just got this misfire code, cylinder 4. I pulled the coil pack and looked at the plug. Plug was fine except for a rather large gap, .055 at only 10K miles. re-gapped the plug and swapped the coil with number 2. No more miss-fires. I re-gapped all the other plugs, they were all around .052-055, this sucks for such low milage. I won't be using Denso plugs again. I'll stick with Autolite or NGK.
My misfire was due to a small crack in my fuel injector gasket (O ring) was a $3 part and fixed myself. I believe it happened because the o rings are old and my engine over heated 3 times
Did you have to tear it apart to find the cracked O ring?
My Jeep is having the same issue and I noticed that the coolant reservoir actually will end up leaking a lot of coolant on top of the number 6 cylinder and it pool up inside where the coil/sparkplug sits.
I've been through this PITA. The PO300 is the Jeep Liberty computer's way of saying there's a fuel/air problem but it doesn't know why. The OBD will say random misfire but all plugs, coils and seals are fine. No cylinder is misfiring, just the appearance of one caused by the computer running full rich and cutting the spark to various cylinders in panic mode.
If one starts the engine and it runs rough, maybe quits and can smell uncombusted gas, it means some component failure caused the computer to lock on full rich. Shut the engine before it eats the seals. It's not a misfire. If it were the computer would specify the cylinder. Usually, the issue is the MAP sensor fried or clogged. Or the MAF. And there are others.
A pro mechanic will hook a scanner up and identify the issue in a few seconds.
The computer strives to achieve 14.7:1 fuel/air ratio. When any sensor or relay kicks the bucket, it sends the computer into a tizzy that sends out bogus diagnostic info. Disconnect the battery, let the computer calm down, reconnect.the battery, plug in the OBD-II, turn the ignition to pre-start and the computer will eventually pinpoint the problem component.
Just remembered, the Liberty doesn't have a MAF, which is good, one less needless aggravation,
I had two ignition coils with secondary winding issues. This veh was definitely misfiring. I had control to the coils the entire time. The computer did not cut the spark. Are you just saying in some cases it may be an air fuel issue and not an actual misfire?
I believe you. I saw the video.
In my experience with Jeep Liberty is they're cruddy cars and when the PO300 code flashes up on OBD-II it means junk the vehicle and get a new car. The PO300 is the beginning of a bottomless money pit for futile repairs. All money spent on repairs is money lost to get a new car.
The non-specific code for random cylinder misfire, with the vehicle usually over 10 years old, indicates a much bigger problem that the computer can't pinpoint. It's nearly always a low compression issue from age, use, wear & tear, where the computer goes full rich on both banks, dumping fuel out of the engine. The PO300 will cycle over to the MAP, or other, then to PO172 and 175. It means call up a car charity and donate the heap for the tax credit. The car is now a POJ.
haha, you summed up every jeep I've seen
The Liberty shouldn't be called a Jeep. It demeans the legendary name. The Wrangler is the realest Jeep, the Laredo is also a worthy Jeep. The Liberty is a POS.
The PO300 code, quite possibly the worst code any owner would want to see, always means a low compression problem. The computer measures the crankshaft rotational velocity at 1000rpm and the velocity is abnormally low because more than one cylinder isn't working. The problem could be that more than one coil-on-plug packed it in, but the computer isn't capable of identifying the affected cylinders. It can ID one without a hitch. Just not two at once because a cheap bargain basement Liberty.
The PO300 code usually means, and absolutely verified by the smell of raw gasoline vapour wafting up the nose, that the valve seals of at least two cylinders are blown, with repair cost probably in excess of vehicle value. That's why I paid the bucks for a quality Laredo next door to my neighbour's trusty Wrangler. I hate fixing BS car problems and avoid by paying the bucks up front for a quality, reliable vehicle and maintaining it properly.
Thank you
Thank you for your video. Please Where can I find Spark plugs (to buy) for 2005 Jeep liberty. My car engine check is flashing and sending a P0300 multiple Cylinders misfire detected
I have that problem with my jeep grand cherokee 2008 it has the code p0300 but the gas price is fine, what could be the problem?
I have a blinking check engine light(PO300) and a O2 sensor code,my muffler is BAd you can see inside of it, and when the light blinks I lose power...I'm going to get all the coils and plugs replaced and the muffler..should that do it?
I have a 2007 Jeep Liberty, I have Changed All The Spark Plugs, Coil Packs and all 4 oxygen sensors and i am still getting Multiple Misfires?
My Liberty 03 has been misfiring lately but I replaced the coils plugs. 02 sensors , crank and the codes are still saying they need to be replaced
I need to know about 2.8 liter diesel engine and how to change water pump and what all comes with new one
Hello, I have machine Dodge nitro 3.7 ekg. I read all your comments but did not understand what the problem is, Connected the computer, no errors at all, but the engine is a little troit and lights wink, please help
Awesome looking computer or scanner tool
For my 2007 Liberty 90,000 miles was the Injector electrics. For some dumbass reason I didn't ohm the #1 Injector leads. When i eventually did, it ohmed at 148 instead of around 12.5. So that explains why I had low rpm misfires under 500rpm. Likely upon startups, bc it started and idles fine. Doesn't miss otherwise.
Bought reman Denso 6-pack on ebay for $72. I'm just replacing that one Injector #1 bc I'm like that, so I'm gonna try to do that without having to remove anything but the #1 and #3 coils and fuel rail bolts on both sides. Maybe the air intake if necessary.
MOPAR still runs... go figure.. Need to check mine.. THANK YOU.. '07 Jeep Commander, AWD
So has same problem just 2 different cylinder replaced all 6 spark plugs and the 2 coils but still flashing engine light any ideas?
I just got a P0300 error followed by a P0302 error. I'm assuming this means a misfire in Cylinder 2?
I did one on a 03 jeep today and number 3 misfire straight up line and coil ramp replace coil and plug
Nice video. Are all six easy to replace? Thank you
I had the same problem. Internal crack in coolant reservoir tank causes coolant to enter right chamber. Coolant exits tank though small overflow opening next to firewall, and leaks onto #6 and #4 coil, shorting them out. Solution, replace coolant reservoir tank, and #6 coil in my case.
#4 coil also could be damaged also.
Same thing happened to me on my 03 Jeep Liberty or correctional 04 coolant leak down on four and six and threw up po300 I'm going to replace my ignition coils
@@mattlonproctor7221 Glad I could help. Blow out the coolant with compressed air if you can.
regards,how fix problem p0300 ,i have problem ?
Guessing the coils didn't actually resolve the issue. Getting ready to mess with the O2 sensor located just before the passenger side of the catalytic converter based on research with results provided
'3 way' catalytic converter meaning there's two total. In relation to even numbered and odd numbered cylinders
Pretty rare to lose 2 coils that are separate from one another
nice wow
Is the ignition drop test safe for the engine? and is it really a simple as pulling the coil wire and if the rpm's drop thats the one you change?
if the rpms drop then that means that cylinder is contributing, its the one that doesn't change would be the problem cylinder, and it shouldn't hurt anything as long as you do it quickly newer vehs should have some type of injector cutoff but you never know
Cly 3 keep misfiring I’ll change it and I’ll go out what could be the problem
Hi, thank you for the useful video, my question is why it did not show oxygen sensor codes instead of P0300 Multiple Cylinder Misfire? My jeep gave me the same code with a very noticeable misfire, and the dealer charged me $600 for injection cleaning and spark plug replacement, although they were replaced not long time ago. It is still giving me the same code and the same symptoms (misfire) from time to time.
Try this if you still have it th-cam.com/video/mt9iUGWOk8I/w-d-xo.html
Have u ever had a coil melt down? 03 liberty 3.7 cylinder 2
Have code faults for #1 misfire, fuel injector 1 circuit open, and Bank #1 lean.
There is a slight rough idle, but no misfire perceived, and it runs fine under load and high speed. Doesn't burn oil. Gets 15mpg combined mileage. Ran fine when I got it 64,000 miles. Now it has 110,000 miles. It has had this issue for about 10,000 miles. Not getting worse, but so far plugs and coils and cleaning intake hasn't corrected it.
I checked and cleaned Injector and Coils wiring connections and they look good too. #1 Injector plug had some oil in it, somehow. Cleaned it very well with first brake cleaner, then electronics cleaner. Let it dry and reassembled.
Can bad Injector o-ring cause this? I already ruled out spark plug, coils, valves, and did intake cleaning.
I have not checked orings and the wiring from #1 Injector to the computer control. And don't really know how to.
Any tips on checking Injector and its wiring and control while it's still in the head? Thanks!
Check the ohms on injector
So when u do a drop test. The ignition coils that could possibly be bad are the ones that don't drop in the rpms ? Great video by the way. I am working on a 2006 jeep liberty.
Correct. Coils that are contributing will cause a drop in rpm. The bad coil will make no difference because it is not contributing.
Hi
What are the code faults?
p2096
p2098
Hello I just finished watching your video. I am having similar issues with my 2005 Jeep grand Cherokee 3.7 intermittent P0303 code., cylinder three misfire. I have change the ignition coil spark plug occasionally. I have tested by putting the ignition coil code. I have even disconnected the connector to cylinder 3 With no change. I can disconnect any other ignition coil cable and there is a drop in rpms. I am thinking about changing the AIC switch at the fuel injector on cylinder three...any other ideas? By the way I will get a check engine light code pertaining to crankshaft sensor in which I changed both crankshaft and camshaft sensors still the occasional P0303 error. My engine was rebuilt 1.5 years ago with 4000 miles plus catalyst converters were changed 1.5 years ago since the rebuild....thanks in advance....
Sometimes with high mileage, the Liberty 3.7 v6 coolant reservoir tank or its rubber hoses can become brittle with engine heat & age
And can leak coolant on the rear two left cylinders .
And can cause this error code.
It recently happened with
my 04 Liberty 3.7 V6
@@frankfitzpatrick5300 shouldn't I be getting smoke at the tail pipe?
@@ninpo23tj no , the water from the coolant tank lower hose just leaks into the recessed spark plug holes , below the coolant reservoir tank & arks on the spark plugs causing misfires !!
Not into the combustion chambers where it would cause white smoke.
I hope this helps
@@frankfitzpatrick5300 Thanks but I have check the level of my coolant tank weekly but I will check again. Note: I had the engine head gasket replaced two years ago and only put 5,000 miles since. Thanks for your insight!
i have a 3.7 misfiring and when i unplug each coil i get a rpm drop what would be my next test ? injectors maybe?
Any luck figuring it out
@@zakiramjan9822 no luck so far maybe the mass air flow
Hello, I just watch your videos and need some insight for I have a 2005 jeep grand Cherokee 3.7 flashing check engine light runs rough-runs like shit as soon as I start it and drive it. It used to have an occasional P0303 and in which I had changed that #3 ignition coil and new set of plugs, worked fine but sometiimes the P0303 comes on and ran ok and cleared it with scanner. Now I get flashing check engine light runs rough-runs like shit as soon as I start it and drive it. I did the drop cylinder test, nothing...any advice would be appreciated! Thanks.
If your still having the misfire on cylinder 3 it could be something else like compression or fuel. Any other faults along with the p0303
@@PositiveLeadDiagnostics thanks for reply...I decided to change all my ignition coils and not one at a time when they fail individually and now it runs great!
I already changed cylinder 6 but it the car still says cylinder 6 misfired what do I do
Bladimir Pujols did you unplug the battery long enough to clear the code? Or use a scan tool to clear the code? If it cleared, has it since returned? If the coil was replaced was the spark plug also? If code was cleared after coil and plug replacement and the code returned then further diagnostic will need to be done looking closer at the Injector itself and/or a cylinder leakdown test to determine if the valves are damaged or worn. Once you have that knowledge you can determine if it makes sense to further repair it.
I replied coils and plugs still have it. Changed all 6 injectors still there ? What's next burn it ?
Might as well keep throwing parts at it instead of diagnosing the actual problem. Everything is backwards these days so why not 🤦♂️
I had a misfire on cylinder 4 on my 2004 Jeep Liberty... I replaced the spark plug and coil pack..(still same problem).. any suggestions anybody???
did you fix and how
how does a misfire create a lean condition ? it should create a rich condition ( unburned fuel going by the 0 2 sensor
When it’s misfiring it’s basically turns that cylinder into an air pump. Yes there is unburned fuel but there’s also a ton of oxygen that the oxygen sensor. I think there’s a long thread somewhere about the oxygen sensor and what does it read.. oxygen or fuel. The tomato sensor. Maybe it’s on iATN. Somewhere
Nice video. My wife has a 2008 liberty with the 3.7. She told me it was shaking and flashing engine light. I fired it up and it was indeed shaking. I scanned it with a cheep scanner and said improper ionization coil in cylinder 3. I pulled the coil off s d pulled the plug out. Seen nothing wrong visually. Put it back together and no more misfires. It’s been 3 months and still no misfires. I did add some dielectric grease to the boot. I wonder how it went from misfire to no misfire,?
Sometimes when you start touching things and moving thing around you can accidentally fix it. Could have been a contact issue or something like that. Happens more often than not.
What is a P0108 mean
i have a question. i just bought a liberty 3.7 2005. I'm haveing similar issues. but my coolant reservoir have a crack in itand leaks onto the coil 4 and 6. could coolant cause a misfire eventho the boot covers the spark plug. ans 2nd question. on this vehicle it has green coolant in it would that throw off the compression in the fluid
Lexy yes it it could very well be a big pro don't no why they put it the crazy .
Lexy don't no if you fixed yet but
Hello, Would be good to show a proper ignition coil ramp as confirmation.Thanks
I did at the 6:00 mark
Question I have an 06 jeep srt8 Grand cherokee 6.1l hemi it's at the dealership dey said its multiple misfires said everything is gud maybe the flywheel or the computer for the engine cuz I had it replaced from ah guy in Florida cuz dey discontinue the one for my truck
Couldn't use the scan tool to do the power balance test? or look at misfire pids? Also, I know coils are super common on everything, why did you go straight to coils vs injectors or vacuum leak?
I was just going with what I thought would be easiest check first
Jee
Misfire #4 cyl. Engine not running rough but light returns. ...replaced coil. Any suggestions?
my 2009 liberty has 206k. has a p0300... replaced the usual. still didn't fix the issue.
arnoni11 hey any luck?
@@alexg8460 yup cheap 02 sensors . i now have to replace my cats because of it
Wow i have bad missfire code and start stall, changed every sensor including 2 ecu and nothing. Only thing i have left is 02 sensors going crazy here
Forgot to mention my 2 of my injectors are dumping too much gas into the system already replaced them and nothing.
@@alexg8460 me being cheap caused the issue. now have to replace the cats
2005 Jeep Grand Cherokee 3.7: I had engine light flashing and then staying on. Only code was P0300. I replaced all the spark plugs and ignition coils. Cleared the code and the flashing engine light came back on the next day and again only code was P0300. I obtained a "FOXWELL FW601 Elm327 Obd2 Scanner WiFi Code Reader Car Diagnostic Tool" and downloaded several OBD apps for my iPad until I found one that would allow me to load the Cylinder Misfire Cyl 1 through Cyl6 so I could see what Cylinders were misfiring. The IOS App was OBD JScan free version. This revealed that Cylinders 2, 4, and 6 had around 50-60 counts of misfiring. Since all three cylinders were are on Bank 2, I decided to replace Oxygen Sensors for Bank 2. I first replaced the upstream O2 sensor for Bank 2 and thank God, its been running fine now for three days. I never replace the downstream O2 sensor since the upstream fixed my issue.
Don't believe everything you read i done the same thing and replaced the coil twice and still had a miss fire at the number 4 cylinder on the 3.7 liter !
I just watched a guy change the upstream fuel sensor on bank one and it fixed it
I need help
trouble codes are engineered for you to start with the lowest number.
will this cause car to run in "limp mode" less than 1500rpms?
I'm in limp mode also , won't go over 2500
Ignition switch. Video for ignition switch
1 3 and 5 for me
shorted primary or secondary???
secondary windings
I ask as I've seen multiple people say both and I don't see the difference in the patterns. same straight up start get called both primary and secondary. Do you know the difference? ??
A shorted primary will look almost like a square wave. Shorted secondary looks like the one in the video
Simple if you have the scanner.
Simple without the scanner too. For the diy guys Cylinder drop test, swap components and redo the cylinder drop test.
What if I have a misfire on cyl 2
P2317
I have the same problem with my dodge nitro 3.7L .. after starting engine.. engine check light flashing .. and the engine start shaking ..
I don’t know what to do with it ..
can anyone suggest a solution.. 🙏🏻
Abdulrahman Thwaini That means you have a serious random misfire and you will need some type of code scanner
Have you solved the problem ? What was wrong ?
That first 1 was almost ok
I just switched coils and seen if misfires changed to other plugs. Stayed on same # plugs. Always have blue powder on plugs and wires. These Liberties SUCK! There's something wrong in design . Don't get taken with you need new coils!
fools not changing the spark plugs at 30K is the biggest issue, OE plug is NGK copper v-power. :)
Throttle, thks. Done plugs but there's something wrong with electrics. Had some dry days and now all dash warning lights that usually come on and off and the intermittent misfires stopped!. (was getting engine, anti skid and low tire) Now jeep runs fine. When it rains and humid again they'll all come back on and the miss fires will return. Bad chip, bad connect some where? Too intermittent for a mechanical I think. If I need to go out of town I just take the old F-150.
BlueRoseRocketBand there could be an electrical issue. Check the pcm connections inside and out