I have gotten so many different “could be” or “yeah, most likeliest” in the past few days I’m going nuts! My ’87 944S has 140K, and “has” low oil pressure. I pulled out the relief valve, sealed and cleaned it and it didn’t do much. So, my local calls have said things from rod bearings to main bearings (total motor rebuild), to maybe even a defective tensioner in the head. I am taking the car in to another shop for a solid diagnoses (again), to see what the true oil pressure is, but after all the calls the most honest (seemingly anyway) guy is telling me “No way, 16 valve bottom ends are bullet proof, no rebuild needed at 140K” (he hasn’t seen the car yet although).
My dealer has told me that I am driving a time bomb in which is going to grenade if I drive it, due to the oil pressure being too low and possibly starving the top tensioner of oil. (the car reads 5 bar on cold startup and slowly drops to about .9-1, to make the light blink only barely, at hot idle). I found thru investigation that a previous owner complained about this problem about 15K ago. The dealer had recorded at the bottom of the page “car displays low pressure at idle, cause - replace pressure relief valve.” They never replaced it, but the valve looked to be in great shape and the internal spring seemed to close the bypass holes off very tightly.
I apologize for the myriad of crazy details, but it is getting so hard to find trust worthy diagnosis any more! HELP!! Thanks-
JS