Slow build oil pressure
09-25-2003, 08:35 AM
#16
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I had a lot off lister noise to when the problem started, i was unable to get pressure at all, at had the car towed to the shop.
I dont think a cleaning agent is enough for celaning of the oprv, yers of old oil-gunk builup on the oprv is only removed with abressive methods (e.g. wet sanding paper) i even used the electrical wire brush the 2. time, and it was'nt enough, problem returned. Only after wet sanding the 3.rd time i solved the problem.
I dont' have any lifter noise now.
I dont think a cleaning agent is enough for celaning of the oprv, yers of old oil-gunk builup on the oprv is only removed with abressive methods (e.g. wet sanding paper) i even used the electrical wire brush the 2. time, and it was'nt enough, problem returned. Only after wet sanding the 3.rd time i solved the problem.
I dont' have any lifter noise now.
10-01-2003, 08:48 AM
#17
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Hi,
944ZEN..... I will use this wet sanding method and hopefully it will take away the little bit of lifter noise that has remained... thanks for the advice..
944ZEN..... I will use this wet sanding method and hopefully it will take away the little bit of lifter noise that has remained... thanks for the advice..
10-01-2003, 09:38 AM
#18
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It's a no brainer,, the original equiptment Porsche filter is really cheap and the best option to use, and the check valve work's,,, this much I do know, especially after all the oil related issues I have had.
I have got to say that as much as I love the 944 this OPRV issue is the real achilles heel of the whole car, if this goes wrong the ca sounds like a bag of spanners being chucked around, and you feel like the world is falling in around you.
but then thats why we drive the 44's right ?
I have got to say that as much as I love the 944 this OPRV issue is the real achilles heel of the whole car, if this goes wrong the ca sounds like a bag of spanners being chucked around, and you feel like the world is falling in around you.
but then thats why we drive the 44's right ?
10-01-2003, 04:59 PM
#19
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johnjcoyle
yeah,... *;"% thought i bought a car in good shape in Feb. 2003, changed seals and then sudden this OPRV issue. At first the pressure was building slowly, but after 2days and nights, on a lovely Saturday morning, i got in the car; turned it over, and NOR Pressure at all. I cranked it for like 60 sec. and then decided this is going to ruin the bearings and stopped. I had to call assistance, and get the car towed to my friends shop. This was at 11 AM where everybody in the neighborhood could see that this "Nice looking car" was not able to run
THATS EMBARRASSING.
yeah,... *;"% thought i bought a car in good shape in Feb. 2003, changed seals and then sudden this OPRV issue. At first the pressure was building slowly, but after 2days and nights, on a lovely Saturday morning, i got in the car; turned it over, and NOR Pressure at all. I cranked it for like 60 sec. and then decided this is going to ruin the bearings and stopped. I had to call assistance, and get the car towed to my friends shop. This was at 11 AM where everybody in the neighborhood could see that this "Nice looking car" was not able to run
THATS EMBARRASSING.
10-01-2003, 10:03 PM
#20
Burning Brakes
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Last week as I waited for my ball joints to come in, I decided to remove the oprv and clean it for the third time. I wetsanded it as 944zen suggested and although it still has some scoring, it does look much cleaner than the two previous cleanings that it had recieved. With the new pickup tube seal and the freshly cleaned oprv, hopefully I will find the delayed oil pressure to be fixed this weekend when I out everything back together.
10-02-2003, 03:14 AM
#21
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BEWARE:
The Wetsanding i did. I used kerosene as the wetting stuff not water, and i wrapped the paper around the OPRV and turned it around, thus only sanding round the piston not along it, not to make groves in the longitudinal direction, The same way you sand a old brake piston.
Before inserting i used brake cleaner, and oiled it with engine oil.
The Wetsanding i did. I used kerosene as the wetting stuff not water, and i wrapped the paper around the OPRV and turned it around, thus only sanding round the piston not along it, not to make groves in the longitudinal direction, The same way you sand a old brake piston.
Before inserting i used brake cleaner, and oiled it with engine oil.
10-02-2003, 12:50 PM
#22
Burning Brakes
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I forgot to mention that the scoring was there prior to the wetsanding. I used water with the 2000 grit wetsanding paper and applied light pressure. The oprv now feels a lot smoother and I didn't feel or see any additional scoring caused by the wet sanding. If I can find the time, I'll post a few before and after pics once I get home. Hopefully the scoring is minor enough so that I don't have to replace it.
10-02-2003, 01:24 PM
#23
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There are only two things which can cause this. OPRV and the oil pick up line (as has already been said).
The Oil pick up line is a no-brainer. If you cannot solve the OPRV issues (as listed below) then you must have a broken pick-up line, and you need to crack open the sump and replace it!
The OPRV is different between early and late cars. The early cars used a 3 piece valve, whereas the late cars used a 1 piece. There is also an update available to give the early cars a 1 piece valve.
In the early cars, the lining up of the oil/water housing is CRITICAL. the valve actually moves backwards into the housing when it relieves pressure, thus binding. This however usually gives the symptoms of having a 5 bar reading all of the time.
I was speakng this afternoon to Peter Sanden (Local 944 guru.... 10 years working on them), he says that he recently had the same problem with a customers car from Stockholm. As far as he had seen in 10 years, it was always the pick up pipe, but when they checked this car, the pickup pipe was intact. A bit of head scratching later, and they fitted an updated 1 piece valve into this car, and it ran perfectly.
The message here, is to basically find a local specialist, and have him try a new updated valve. Yes you can go the way of cleaning the existing one, but who is to say that this won't give further issues down the line (like constant low pressure 'cos you out-of-rounded the valve, thus not getting enough oil to the engine, thus spinning a rod bearing!??). This is one part not to skimp on. Bite the bullet, and spend the money (it seems though that they are expensive over the pond. Peter was telling me 1600 SEK - ca. $160, but pelican has them for $270!!!)
At least a specialist worth his salt will also take the part back if it doesn't fix the issue (then it's really time to get your hands dirty!)
Filters are also a small issue. Some filters do not have the anti-drain feature built in. DON'T TOUCH THEM WITH A 6-FOOT POLE! OEM has it, Mahle has it, and the rest MIGHT. For 8 bucks (or whatever), it's worth it also.
The Oil pick up line is a no-brainer. If you cannot solve the OPRV issues (as listed below) then you must have a broken pick-up line, and you need to crack open the sump and replace it!
The OPRV is different between early and late cars. The early cars used a 3 piece valve, whereas the late cars used a 1 piece. There is also an update available to give the early cars a 1 piece valve.
In the early cars, the lining up of the oil/water housing is CRITICAL. the valve actually moves backwards into the housing when it relieves pressure, thus binding. This however usually gives the symptoms of having a 5 bar reading all of the time.
I was speakng this afternoon to Peter Sanden (Local 944 guru.... 10 years working on them), he says that he recently had the same problem with a customers car from Stockholm. As far as he had seen in 10 years, it was always the pick up pipe, but when they checked this car, the pickup pipe was intact. A bit of head scratching later, and they fitted an updated 1 piece valve into this car, and it ran perfectly.
The message here, is to basically find a local specialist, and have him try a new updated valve. Yes you can go the way of cleaning the existing one, but who is to say that this won't give further issues down the line (like constant low pressure 'cos you out-of-rounded the valve, thus not getting enough oil to the engine, thus spinning a rod bearing!??). This is one part not to skimp on. Bite the bullet, and spend the money (it seems though that they are expensive over the pond. Peter was telling me 1600 SEK - ca. $160, but pelican has them for $270!!!)
At least a specialist worth his salt will also take the part back if it doesn't fix the issue (then it's really time to get your hands dirty!)
Filters are also a small issue. Some filters do not have the anti-drain feature built in. DON'T TOUCH THEM WITH A 6-FOOT POLE! OEM has it, Mahle has it, and the rest MIGHT. For 8 bucks (or whatever), it's worth it also.
10-02-2003, 01:53 PM
#24
Nordschleife Master
I'd forget about any mechanic-in-a-can or partial solution like sanding a part. At best they mask the problem for a while, and you don't want to mess around with low oil pressure.
10-02-2003, 03:17 PM
#25
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NOW i don't agree that sanding is not a solution.
Here's my theory:
Years of hot oil passing by, and when you stop the car hot, the oil will most likely place some deposit on the oprv. The same thing happens to jets i carburettors from the gum building component off the petrol. That why you run a pertol system cleaner once in a while.
I know for instance that my car has been running hot, since the radiator was missing 1/3 og the colling fan's (or lamels or what its called). So maybee the gum builup is worsened when the oil crack due to high temerature. I changed the radiator and it now runs nice and cool.
So the carefull sanding will eventually remove the gum deposit that makes the diameter off the oprv bigger than new, and thus sticking. This is like normal procedure in the workshop that my friend run, when a car comes with a oil pressure problem.
AND Last: Why not try the free stuff first, sanding is free, a new oprv cost.
F.I:Y My oil pressure is now 4 - 4.5 on hot running, and 2-2.5 at hot idle.
I think "ahofam123" cheked the pick up tube a month ago, he even posted pictures. evt. search.
Here's my theory:
Years of hot oil passing by, and when you stop the car hot, the oil will most likely place some deposit on the oprv. The same thing happens to jets i carburettors from the gum building component off the petrol. That why you run a pertol system cleaner once in a while.
I know for instance that my car has been running hot, since the radiator was missing 1/3 og the colling fan's (or lamels or what its called). So maybee the gum builup is worsened when the oil crack due to high temerature. I changed the radiator and it now runs nice and cool.
So the carefull sanding will eventually remove the gum deposit that makes the diameter off the oprv bigger than new, and thus sticking. This is like normal procedure in the workshop that my friend run, when a car comes with a oil pressure problem.
AND Last: Why not try the free stuff first, sanding is free, a new oprv cost.
F.I:Y My oil pressure is now 4 - 4.5 on hot running, and 2-2.5 at hot idle.
I think "ahofam123" cheked the pick up tube a month ago, he even posted pictures. evt. search.
10-05-2003, 06:08 AM
#26
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944ZEN, Peckster,Pikey7,ahofam123......
No I am confused,! I will try the sanding method and post the results, however reading Pikey7's info about early or late OPRV's 1 piece or 3 piece has me thinking.
Basically I bought a 1988 car. to my knowledge and to the Porsche dealer down the road this means a 1 piece OPRV.
I bought a new 1 piece OPRV., Inserted it only to find out that it was bad stock and did not work!!!!!!.
So I took it back and got a new one. This seems to work a lot better but most of the time I am getting 4-5 bar oil pressure.
Therefore 2 things are going to happen.
#1 sand the OPRV gently to see if this works.
#2 Can anyone please confirm that a 1988 NA has a 1 piece OPRV as standard or am I using the wrong Valve . At the same time does anyone know if an alignment tool needs to be used for a 1 piece valve ?
Many thanks for your help on this one.
John
Belgium 1988 NA 944. Alpine white.
No I am confused,! I will try the sanding method and post the results, however reading Pikey7's info about early or late OPRV's 1 piece or 3 piece has me thinking.
Basically I bought a 1988 car. to my knowledge and to the Porsche dealer down the road this means a 1 piece OPRV.
I bought a new 1 piece OPRV., Inserted it only to find out that it was bad stock and did not work!!!!!!.
So I took it back and got a new one. This seems to work a lot better but most of the time I am getting 4-5 bar oil pressure.
Therefore 2 things are going to happen.
#1 sand the OPRV gently to see if this works.
#2 Can anyone please confirm that a 1988 NA has a 1 piece OPRV as standard or am I using the wrong Valve . At the same time does anyone know if an alignment tool needs to be used for a 1 piece valve ?
Many thanks for your help on this one.
John
Belgium 1988 NA 944. Alpine white.
10-05-2003, 06:28 AM
#27
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Oups.. 
I think ahofam123 and I both got the old style 3 piece OPRV system.
In the procedure i described above i did NOT talk about the 1 piece setup, witch is not a "normal" style OPRV as i other engines.
The 3 piece is simple a Piston, a spring and a retaining Nut; where the piston moves back and fourth in the oprv cylinder bore pressed by the oil in one side and the spring on the other side. This style of oprv requires the cylinder bore and the piston to be close tolerance to work properly. And by age, if theres any sort of "deposit build-up" or scores on the piston, the tolerances are lost, and therefore the optv is not working well. Deposit may even be Sludge like oil substances that is sticky, and then "gluing" the piston in its bore.
The ONE piece assembly is NOT moving in the oprv cylinder. It screwed in and sit's there. All the "moving" mechanic is inside the oprv, so when you change it you change the piston and cylinder bore together, and then tolerances should be better.
SO: - DO NOT Sand a 1 Piece OPRV, since the moving part is inside. -
- DO sand the piston in the 3-piece oprv.
Thats My Advice.
I think ahofam123 and I both got the old style 3 piece OPRV system.
In the procedure i described above i did NOT talk about the 1 piece setup, witch is not a "normal" style OPRV as i other engines.
The 3 piece is simple a Piston, a spring and a retaining Nut; where the piston moves back and fourth in the oprv cylinder bore pressed by the oil in one side and the spring on the other side. This style of oprv requires the cylinder bore and the piston to be close tolerance to work properly. And by age, if theres any sort of "deposit build-up" or scores on the piston, the tolerances are lost, and therefore the optv is not working well. Deposit may even be Sludge like oil substances that is sticky, and then "gluing" the piston in its bore.
The ONE piece assembly is NOT moving in the oprv cylinder. It screwed in and sit's there. All the "moving" mechanic is inside the oprv, so when you change it you change the piston and cylinder bore together, and then tolerances should be better.
SO: - DO NOT Sand a 1 Piece OPRV, since the moving part is inside. -
- DO sand the piston in the 3-piece oprv.
Thats My Advice.
10-05-2003, 06:36 AM
#28
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Hi 944ZEN,
Just to say thanks for your input.
I now know I have a 1 piece valve. However I also have the old 1 piece valve to use as an experiment.
I see that it is made up from the valve body, a nut end , a spring and the piston.
The whole assembly is held together by an O ring at the bottom of the valve where it pressure fits to the nut end.
Therfore I have taken the thing apart, found there to be gunk on the inside of the valve and around the piston.
I will clean this one and buy new Porsche O rings to put it together again and see if this works.
Of course with a 1 piece valve there is another O ring at the top of the valve to seal the top end.
By the way does anyone know if an alignment tool is needed for a 1 piece valve????
Regards,
John J
Belgium 1988 944 NA Alpine White.
Just to say thanks for your input.
I now know I have a 1 piece valve. However I also have the old 1 piece valve to use as an experiment.
I see that it is made up from the valve body, a nut end , a spring and the piston.
The whole assembly is held together by an O ring at the bottom of the valve where it pressure fits to the nut end.
Therfore I have taken the thing apart, found there to be gunk on the inside of the valve and around the piston.
I will clean this one and buy new Porsche O rings to put it together again and see if this works.
Of course with a 1 piece valve there is another O ring at the top of the valve to seal the top end.
By the way does anyone know if an alignment tool is needed for a 1 piece valve????
Regards,
John J
Belgium 1988 944 NA Alpine White.
10-09-2003, 11:05 PM
#29
Drifting
Thread Starter
Well, lets see if this does the trick. $309 with tax for a new OPRV. Geez, I wonder if my parts guy is on commision. If he is, I BETTER get a Christmas card. I'll install it on Sat and post results, gotta go ER is on and the missuz is lookin for me.
