tomsbuick Posted December 10, 2017 Share Posted December 10, 2017 My 1990 coupe runs good overall but is had a oil leak. I replaced the valve cover gaskets, oil pan gasket, PCV valve and i still have a oil leak. It leaves a oil spot the size of a silver dollar. My oil pressure is over the half way mark-maybe 5/8 mark on the dash gauge. Is there a way to relieve oil pressure like put a small hole in the oil filler cap? Is there a oil pressure relief valve on the engine? Any comments appreciated. :S Link to comment Share on other sites More sharing options...
Ronnie Posted December 11, 2017 Share Posted December 11, 2017 It would be unusual for the oil pump to put out enough pressure to cause a leak. There is a pressure relief valve that should open if the oil pressure gets too high. Even if the pressure did get too high, drilling a hole in the oil filler cap wouldn't help with an oil leak. Any pressure inside the engine should be relieved by the PCV valve if it is working correctly. Since you seem to indicate the oil pressure is higher than normal it's possible the oil pressure sensor is bad causing the oil pressure reading to be inaccurate. Sometimes they leak when they go bad. You really need to get under the car and look for the source of the leak (follow the drip) to determine where the oil is coming from. Replacing parts without doing that is a lot of work and can get expensive. :) Link to comment Share on other sites More sharing options...
2seater Posted December 11, 2017 Share Posted December 11, 2017 Oil pressure by itself shouldn't cause an oil leak, and the oil pressure sender itself is somewhat notorious for giving erroneous readings. The only place there is a gasketed surface that sees full oil pressure is at the rear area of the front engine cover and where the oil filter adapter bolts on. Yes, there is an oil pressure relief system, and is part of the oil filter adapter system. A couple of questions, did the oil pressure reading always seem a little high and under what conditions? Has the oil been changed to a different type or viscosity recently? Basically asking if this is a new issue? Personally I run a bit higher oil pressure via a shimmed spring in the pressure relief, primarily because of the engine oil cooler I added plus a oil feed to the turbo, and will indicate at about 3 o'clock on the gauge at speed, and higher when cold. This is with 0w-30 synthetic oil. No leaks. Link to comment Share on other sites More sharing options...
DAVES89 Posted December 11, 2017 Share Posted December 11, 2017 I just replaced mine on the Black. You can just look down through the top on the passenger side. It will be near the crank shaft pulley area. If you see oil in that area that will be what it is. Link to comment Share on other sites More sharing options...
Frogware Posted December 11, 2017 Share Posted December 11, 2017 Tom how many miles are on her? I would do as suggested above especially where it is leaking from. Also if everything checks out you should check the Drain plug because the seal does wear out over time and leak no matter how tight you put it. Link to comment Share on other sites More sharing options...
tomsbuick Posted December 11, 2017 Topic Author Share Posted December 11, 2017 Car has 156000 miles and uses 5-30 synthetic valvoline blend. So the leak may be coming from the oil filter adapter unit? Pressure can be relieved at this unit? i will check it out. :D Link to comment Share on other sites More sharing options...
DAVES89 Posted December 11, 2017 Share Posted December 11, 2017 I don't believe the leak will not be coming from the oil filter adapter unit. None of my cars have leaked there, and as I have been under dozens of 3800 motors [pulling parts in salvage yards] I can tell you with pretty good certainty that that is not where the leak is. The gasket is well designed for it not to leak. I would start with the oil pressure sending unit. If you ever have to replace it you will see that is made of a cast matieral body with a seal on the top for the electrical part of the unit to protrude to then plug into the harness. This is where the leak will be. Link to comment Share on other sites More sharing options...
2seater Posted December 11, 2017 Share Posted December 11, 2017 Car has 156000 miles and uses 5-30 synthetic valvoline blend. So the leak may be coming from the oil filter adapter unit? Pressure can be relieved at this unit? i will check it out. :D I wasn't suggesting modifying anything, especially not reducing oil pressure. The leak is almost certainly not caused by excess pressure. If the pressure indication is a concern, it should be verified with an actual gauge, and if out of spec, determine the cause. Usually an engine doesn't get tighter with age, so the question remains, has it always indicated where it does now, or is this a new condition? The sending unit is a prime candidate for both a leak and erroneous readings. Link to comment Share on other sites More sharing options...
B29 Engineer Posted December 11, 2017 Share Posted December 11, 2017 When I Bought My 1990 Reatta The Oil Pressure Indicator Read Max All The Time. I replaced The Oil Sender,Easy Fix, It Now Reads Between 50/80, Members On This Site State That The Reading I Was Getting Was Quite Normal. Good Luck, Hope This Help. B29 Engineer Link to comment Share on other sites More sharing options...
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