oil pressure problem
08-20-2002, 07:52 PM
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oil pressure problem
O.K. In another thread I've been working on an oil pressure problem. I've taken out the pressure relief valve (its a 87 and should have a 1 piece but has a 3 piece valve instead) and cleaned it up. No luck. I.ve overfilled the oil 2 quarts to see if the oil pickup tube is cracked, and still no pressure. My next question is how would you check to see if your oil pressure sending unit is working? Does it send voltage to the oil pressure gague and what voltage should it send? I dont want to buy a new 1 piece pressure release valve if I dont have too! Also someone recomended filling the oil tube under the oil filter full before starting so there wouldnt be an air lock and no luck. Anyone know the voltage the sending unit should be sending? I guess I could state the problem also since someone may not have read the other post. I show no (0) oil pressure at start up. I've let it run about 15 sec. everytime I try something and no luck. I'm hoping the sending unit is bad I dont want to run the engine till the valves start chattering I'd rather fix the problem first.
08-20-2002, 08:15 PM
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It would be nice to attach a mechanical oil pressure gauge to the engine. Does anyone know where you would do such a thing?
Usually the oil pressure sender will fail in such a way that when you turn you key in the ignition to the "on" position, the gauge pegs (before you have started the car). However, they will occasionally fail and read zero. Make extra sure that the wires are correctly hooked up. I know mine got flakey and it was the wires coming off of the spade terminals.
Usually the oil pressure sender will fail in such a way that when you turn you key in the ignition to the "on" position, the gauge pegs (before you have started the car). However, they will occasionally fail and read zero. Make extra sure that the wires are correctly hooked up. I know mine got flakey and it was the wires coming off of the spade terminals.
08-20-2002, 11:22 PM
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Mxsav,
I'm curious as to your oil pressure problem. Did this problem crop up all of a sudden, or is this an existing issue? I'm thinking that your oil pressure issue came with the car and has always been there. Sad to say, but from what I've read on Porsche's Tech Bulletin #3 and what your post indicates, I think you'll need to get the 1-piece valve to fix your problem.
First off, 1987 944's never received the 3 piece oil pressure valve. I read a tech bulletin (Tech Bulletin #3) put out by Porsche on the oil pressure valve issue and they clearly state that 1987 model year (which started in July 1986) came with the 1 piece valve. It turns out that for a short period of time the new valves were not corrosion resistant. From October 1986 moving forward, all oil pressure relief valves had the new anti-corrosion treatment.
There is a 1-piece valve that is manufactured as a replacement for the 3-piece valve (to retro-fit 1986 and earlier vehicles), but I've never actually seen this item (other than in pictures). This retro-fit replacement valve for 1986 and earlier vehicles is physically different from the valve that needs to be inside your car. The tech bulletin has pictures and the one for your vehicle is longer, has more threads, and the shoulders (smaller diameter portions of the valve) are in different locations compared to the replacement valve for earlier vehicles. This means that the 3-piece valve's operating characteristics are different than the valve that should be in your 1987 vehicle.
I think that the wrong valve is causing all your problems with the oil pressure.
For 1987 vehicles, the part# for the valve is: 944.107.035.01. There is also an O-ring (944.107.935.11) and a seal (N 043.815.3) that is part of the 1-piece valve. The older 3-piece valves do not have any kind of O-ring or seal (this is what I have in my '86 951).
Hope the information helps.
*****
I'm curious as to your oil pressure problem. Did this problem crop up all of a sudden, or is this an existing issue? I'm thinking that your oil pressure issue came with the car and has always been there. Sad to say, but from what I've read on Porsche's Tech Bulletin #3 and what your post indicates, I think you'll need to get the 1-piece valve to fix your problem.
First off, 1987 944's never received the 3 piece oil pressure valve. I read a tech bulletin (Tech Bulletin #3) put out by Porsche on the oil pressure valve issue and they clearly state that 1987 model year (which started in July 1986) came with the 1 piece valve. It turns out that for a short period of time the new valves were not corrosion resistant. From October 1986 moving forward, all oil pressure relief valves had the new anti-corrosion treatment.
There is a 1-piece valve that is manufactured as a replacement for the 3-piece valve (to retro-fit 1986 and earlier vehicles), but I've never actually seen this item (other than in pictures). This retro-fit replacement valve for 1986 and earlier vehicles is physically different from the valve that needs to be inside your car. The tech bulletin has pictures and the one for your vehicle is longer, has more threads, and the shoulders (smaller diameter portions of the valve) are in different locations compared to the replacement valve for earlier vehicles. This means that the 3-piece valve's operating characteristics are different than the valve that should be in your 1987 vehicle.
I think that the wrong valve is causing all your problems with the oil pressure.
For 1987 vehicles, the part# for the valve is: 944.107.035.01. There is also an O-ring (944.107.935.11) and a seal (N 043.815.3) that is part of the 1-piece valve. The older 3-piece valves do not have any kind of O-ring or seal (this is what I have in my '86 951).
Hope the information helps.
*****
08-21-2002, 12:35 AM
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Todd Holyoak is now promoted to official GURU!!!! Todd redid the advice you gave earlier about priming the pump and filled the oil tube and cranked the engine pully backwards three times and low and behold if now have PRESSURE!!!!! Thanks, Todd now I can sleep tonight. *****, I have no idea how a 3 piece got in this car. The PO died and I have no records so I can only assume it was replaced with the older version at sometime. When I get some extra money I'll buy another. Thanks everyone for the input!! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" /> <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />