For the record, the REAR relief valve (closest to the pump) does have a dump port that serves to limit cold high oil pressure. The grooved piston allows oil to flow from the main gallery to the dump when the engine is fully warm. Increasing the pressure of the spring does NOT change this. All a heavier spring does is to annoy the cooler and cause a premature "switchover" to the cooler. The control valve was introduced in 1970 to allow the new *higher capacity pump* to circulate more oil than the engine consumes. With a grooved relief piston, the cooler is now cooling a greater quantity of oil than the engine is actually consuming. The added benefit is that as the engine bearing clearances open up when old or very hot, the control valve will close and allow that high capacity pump to get to work to keep the oil idiot light off. I very strongly recommend that we not dork around with factory engineering. When you lose oil pressure, it is because your bearing clearances are opening up and less likely, your pump is losing efficiency due to scoring,evidence of poor maintenance. Type 1 engines without an oil filter need us to be very very clean at all times. That means valve adjustments must be performed in clean conditions, and your air filter must be secure and of good quality.
+Co Lin Earlier I was not allowed to reply directly, perhaps thanks to Google +, but now I can for some reason. Anyway, as you can see in my newer video, "Oil Flows and Pathways...", there is no dump port at the rear control valve. I believe that was unique to single relief cases. So that grooved piston serves no purpose on dual relief case, since there is no dump port for it to line up with. If I can get my hands on single relief case, I'll make a video about that, how the grooved piston works.
Colin Kellogg is I believe confusing the old single pressure relief system with the newer dual pressure relief system. The spring and plunger nearest the oil pump does not have a "dump port" on a dual relief case, but it does on a single relief case. The grooved piston or plunger serves no purpose on the dual relief case, but does function on the single relief case to "short circuit" oil from the main galley back to the sump - the single relief case has a passage from the plunger bore to the sump apparently ( I don't have one to inspect but have seen a diagram on the internet ) Since Colin Kellogg has posted a "linked comment", I cannot reply directly.
From What I understand the first pressure relief valve in the rear of the car near the oil pump. Does put all the oil go through the cooler until maximum pressure is achieved then excess will go through the bypass directly to the bearings. The other valve is the actual bypass for full pressure. If the first valve at the rear of the engine sticks, It will put some oil through the bypass do the bearings and some through the cooler which can cause start up oil pressure to be low.....Flickering light. With the spring kit and stiffer springs. It will push more oil through the bearing surface which cannot really hurt much but could may cause excess pressure in the cooler. Those coolers can take some pressure and so can the cooler o rings. It should not make any difference if you use the stock springs or the after market ones. As long as the pistons move freely. The stiff springs may have less chance of sticking open then the stock ones. so this could make your start up oil pressure better if your having problems with oil pressure at start up. Best advice do what you want. and make sure those pistons are not getting stuck. I have the stiff springs and have no issues. only because they have less chance of sticking and will allow oil to go through the cooler only first.
Great video, very informative, especially liked the discussion of how the pressure relief (short) spring stiffness influences the oil cooler bypass spring-plunger function. The spring stiffness specification, found on Table c in section 1.15.3 in the Official Service Manual for Karmann Ghia, for the short spring is 3.1-3.8 kg (6.8 to 8.4 lbs.) force to compress the spring to 20.2 mm (.795”) and for the long spring is 5.6-7.3 kg (12.3 to 16.1 lbs.) force to compress the spring to 44.1 mm (1.736”). Have you measured the spring stiffness for stock and after market springs in order to match each spring force for desired purpose? I have developed a method for this using my drill press and stop set to the correct spring height under pressure on top of a scale and found there is much variation among all springs.
yesterday i took out those plunger to replace the flat "screwdriver" type of head for an allen type screw head and i noticed that the 2 plungers are identical, with no neck cut on the pulley side plunger. do my mechanic put the wrong plungers?
@@marcusgray3805 thank you. I ended up jacking the car up high enough to fit a BIG long flathead screwdriver underneath. It still didn't want to budge, so I used a butane torch to loosen it.
I have a 1994 VW Jetta (2L, auto) which at start has no issues but after about 5 minutes it flags oil pressure alarm. Mostly the alarm is only the dash light, but at times it is also accompanied by a buzz. There are times when I do not get any alarm, but this is very rare. Because of the inconsistency of the alarm I am thinking it has to do with some closing and opening of something (I don't know much about the system, but things make sense when explained). I have replaced both pressure sensors, and that has not changed a thing. Might either of these plungers/valves be my issue? How do I locate them on the block?
My video doesn't apply because it's only relevant to air-cooled VW's. I don't know the 1994 Jetta at all really, and haven't run across a system with two oil pressure sensors. Do you have to pass any sort of inspection ? If not, I add a mechanical gauge in place of one of the sensors, prove that you have oil pressure and no worries. Like everything, look on the internet. If it's a nice car you don't want to add a gauge to or have to pass smog, you might have to find someone who actually knows this system. Thanks for the comment.
I took my relief and control pistons out and i had to use a dowel rod to get them out. there seems to be a seam halfway up the tube that catches the piston a bit until it reaches the top of the tube and then when I release the piston it won't slide out the bottom of the tube as it catches at that 'seam'. is this normal? thanks
stoicokie Mine fell out easily, I was prepared to start the engine and see if the oil pressure would blast them out, but it wasn't necessary. Would have made good video though. Maybe that "seam" or ridge is the result of wear. A good topic to search on over at TheSamba.com, or ask this question there. I really don't know if what you describe is common.
i have a question. I have a 1973 bus with a 1800 motor. it seems especially when it is cold and after sitting it seems like a long time to build up oil pressure. there is a pop thru the exhaust and then it stops rattling. thought it may be the pressure relief valve. had the motor rebuilt 1000 miles ago. any suggestions
richard kantor 1800 = Type 4 ? Big pancake motor ? Not too familiar with these. Hydraulic lifters on these I think - the source of your rattling perhaps. You might make sure the pressure relief plunger(s) are free, not stuck. Any accessory oil cooler installed that might be draining back ?
I'm having overheating issues with my dual relief case here in AZ...I wonder if my spring is too stiff and making my oil bypass the cooler? I just pulled the engine and when I pulled the oil cooler off the case, not even a drop of oil came out of it...is that normal? Thanks for the video!
My grasp is the heavier spring keeps the valve closed more often, forcing more oil, not less, through the cooler. Since the cooler is upright, maybe I'm not surprised if it drains out when the engine sits for a long time. A full-flow filter and oil cooler in the air stream helps a lot in my view.
Is the way you show them the order they go in? Mine fell out quickly and I couldn't see how it came out. Specifically, does the "grooved" plunger have the grooved end at the top and the hollow part at the bottom / touching the spring?
Yes, the hollow ends point downward toward the spring. As I might mention in the video, I don't believe the grooved piston serves any purpose in a dual-relief case, doesn't do any harm though. Has a purpose/does something in a single relief case.
![ร้อยพ่อพันแม่ - WanMai [Official MV]](http://i.ytimg.com/vi/XY2pNYASEbg/mqdefault.jpg)
Thanks for the info.. Now I know why my oil filter gasket has blown twice off... Ill be changing back to the stock springs and plungers
For the record, the REAR relief valve (closest to the pump) does have a dump port that serves to limit cold high oil pressure. The grooved piston allows oil to flow from the main gallery to the dump when the engine is fully warm. Increasing the pressure of the spring does NOT change this. All a heavier spring does is to annoy the cooler and cause a premature "switchover" to the cooler. The control valve was introduced in 1970 to allow the new *higher capacity pump* to circulate more oil than the engine consumes. With a grooved relief piston, the cooler is now cooling a greater quantity of oil than the engine is actually consuming. The added benefit is that as the engine bearing clearances open up when old or very hot, the control valve will close and allow that high capacity pump to get to work to keep the oil idiot light off. I very strongly recommend that we not dork around with factory engineering. When you lose oil pressure, it is because your bearing clearances are opening up and less likely, your pump is losing efficiency due to scoring,evidence of poor maintenance. Type 1 engines without an oil filter need us to be very very clean at all times. That means valve adjustments must be performed in clean conditions, and your air filter must be secure and of good quality.
+Co Lin Earlier I was not allowed to reply directly, perhaps thanks to Google +, but now I can for some reason. Anyway, as you can see in my newer video, "Oil Flows and Pathways...", there is no dump port at the rear control valve. I believe that was unique to single relief cases. So that grooved piston serves no purpose on dual relief case, since there is no dump port for it to line up with. If I can get my hands on single relief case, I'll make a video about that, how the grooved piston works.
Colin Kellogg is I believe confusing the old single pressure relief system with the newer dual pressure relief system. The spring and plunger nearest the oil pump does not have a "dump port" on a dual relief case, but it does on a single relief case. The grooved piston or plunger serves no purpose on the dual relief case, but does function on the single relief case to "short circuit" oil from the main galley back to the sump - the single relief case has a passage from the plunger bore to the sump apparently ( I don't have one to inspect but have seen a diagram on the internet ) Since Colin Kellogg has posted a "linked comment", I cannot reply directly.
From What I understand the first pressure relief valve in the rear of the car near the oil pump. Does put all the oil go through the cooler until maximum pressure is achieved then excess will go through the bypass directly to the bearings. The other valve is the actual bypass for full pressure. If the first valve at the rear of the engine sticks, It will put some oil through the bypass do the bearings and some through the cooler which can cause start up oil pressure to be low.....Flickering light. With the spring kit and stiffer springs. It will push more oil through the bearing surface which cannot really hurt much but could may cause excess pressure in the cooler. Those coolers can take some pressure and so can the cooler o rings. It should not make any difference if you use the stock springs or the after market ones. As long as the pistons move freely. The stiff springs may have less chance of sticking open then the stock ones. so this could make your start up oil pressure better if your having problems with oil pressure at start up. Best advice do what you want. and make sure those pistons are not getting stuck. I have the stiff springs and have no issues. only because they have less chance of sticking and will allow oil to go through the cooler only first.
(FYI) flywheel end is considered front of motor- pulley end is rear.
opposite of any usa cars LOL ,,,,,flywheel is rear on chevy fords etc etc ,,,,,,dont you love confusion LOL
Great video, very informative, especially liked the discussion of how the pressure relief (short) spring stiffness influences the oil cooler bypass spring-plunger function. The spring stiffness specification, found on Table c in section 1.15.3 in the Official Service Manual for Karmann Ghia, for the short spring is 3.1-3.8 kg (6.8 to 8.4 lbs.) force to compress the spring to 20.2 mm (.795”) and for the long spring is 5.6-7.3 kg (12.3 to 16.1 lbs.) force to compress the spring to 44.1 mm (1.736”). Have you measured the spring stiffness for stock and after market springs in order to match each spring force for desired purpose? I have developed a method for this using my drill press and stop set to the correct spring height under pressure on top of a scale and found there is much variation among all springs.
I liked it most people "T" off the oil pressure port by the distributor for oil temp and that's just wrong
Andre from SouthAfrica my 1600 old school have a oilpresure problem wat can it be it starts up good when hot it drops a lot
yesterday i took out those plunger to replace the flat "screwdriver" type of head for an allen type screw head and i noticed that the 2 plungers are identical, with no neck cut on the pulley side plunger. do my mechanic put the wrong plungers?
Good explanation
Can we use Permatex High Tack sealant for oil pump gaskets? Thx
I wouldnt
I just can't find a screwdriver wide enough to get a good grip on the plug! Any suggestions?
Still having trouble with this flat screw not wanting to release. Considering grinding down a chisel
Use an impact screw driver.You use a hammer to loosen or tighten on screws..You can buy them at Lowe's.
Get yourself a tool called a drag link. Looks like a socket with a large flat screwdriver tip. It's been a lifesaver for me
@@marcusgray3805 thank you.
I ended up jacking the car up high enough to fit a BIG long flathead screwdriver underneath. It still didn't want to budge, so I used a butane torch to loosen it.
@@marcusgray3805 drag link socket set?
What’s the stock oil pressure psi?
Usually 10psi per thousand rpm
Thanks very much..
I knew I saw that towel before.
I have a 1994 VW Jetta (2L, auto) which at start has no issues but after about 5 minutes it flags oil pressure alarm. Mostly the alarm is only the dash light, but at times it is also accompanied by a buzz. There are times when I do not get any alarm, but this is very rare. Because of the inconsistency of the alarm I am thinking it has to do with some closing and opening of something (I don't know much about the system, but things make sense when explained). I have replaced both pressure sensors, and that has not changed a thing. Might either of these plungers/valves be my issue? How do I locate them on the block?
My video doesn't apply because it's only relevant to air-cooled VW's. I don't know the 1994 Jetta at all really, and haven't run across a system with two oil pressure sensors. Do you have to pass any sort of inspection ? If not, I add a mechanical gauge in place of one of the sensors, prove that you have oil pressure and no worries. Like everything, look on the internet. If it's a nice car you don't want to add a gauge to or have to pass smog, you might have to find someone who actually knows this system. Thanks for the comment.
I took my relief and control pistons out and i had to use a dowel rod to get them out. there seems to be a seam halfway up the tube that catches the piston a bit until it reaches the top of the tube and then when I release the piston it won't slide out the bottom of the tube as it catches at that 'seam'. is this normal? thanks
stoicokie Mine fell out easily, I was prepared to start the engine and see if the oil pressure would blast them out, but it wasn't necessary. Would have made good video though. Maybe that "seam" or ridge is the result of wear. A good topic to search on over at TheSamba.com, or ask this question there. I really don't know if what you describe is common.
i have a question. I have a 1973 bus with a 1800 motor. it seems especially when it is cold and after sitting it seems like a long time to build up oil pressure. there is a pop thru the exhaust and then it stops rattling. thought it may be the pressure relief valve. had the motor rebuilt 1000 miles ago. any suggestions
richard kantor 1800 = Type 4 ? Big pancake motor ? Not too familiar with these. Hydraulic lifters on these I think - the source of your rattling perhaps. You might make sure the pressure relief plunger(s) are free, not stuck. Any accessory oil cooler installed that might be draining back ?
richard kantor I am having the same issue with my 77. Did you ever find out the cause?
I'm having overheating issues with my dual relief case here in AZ...I wonder if my spring is too stiff and making my oil bypass the cooler? I just pulled the engine and when I pulled the oil cooler off the case, not even a drop of oil came out of it...is that normal? Thanks for the video!
My grasp is the heavier spring keeps the valve closed more often, forcing more oil, not less, through the cooler. Since the cooler is upright, maybe I'm not surprised if it drains out when the engine sits for a long time. A full-flow filter and oil cooler in the air stream helps a lot in my view.
Is the way you show them the order they go in? Mine fell out quickly and I couldn't see how it came out. Specifically, does the "grooved" plunger have the grooved end at the top and the hollow part at the bottom / touching the spring?
Yes, the hollow ends point downward toward the spring. As I might mention in the video, I don't believe the grooved piston serves any purpose in a dual-relief case, doesn't do any harm though. Has a purpose/does something in a single relief case.