Engine Rebuild?? HELP!!

[JeffSchroeder]

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

[ae1969]

Uhmmmmmmmm

Have you seen any evidence of metal shavings?? oil drain plug?

The bottom end on these cars are quite durable......but the rod bearing issue is still a concern.

Have you seen any other problems? Compression Tests? Oil burning? Oil consumption high????/

Any oil in the intake?

[Scott R]

I agreee with AE, this sounds like a simple issue. Which dealer gave you the bad news? I only ask since both of the Denver area dealers are complete crooks when it comes to the older cars.

First off when was the last oil change? Who did it? Did they use a factory (mahle) filter? What weight oil was used?

Do you have any obvious leaks? Such as a bad front main seal?

Like AE said, are you burning oil?

More details please, depending on where in Denver you are you should stop by, I am on my third 944/951 and I know just about every bolt under the hood, I have most of the special tools, and all of the manuals avilable. You can use, or borrow whatever you need. In fact I have many spare parts on hand right down to R12 freon and other hard to get items.

Also which shops have you called? If you have not already call "Isenbud" they are at 8th and I25 and the guy does excellent water cooled work and excellent prices.

PM me if you want and we can talk.

[JeffSchroeder]

Thanks you two, I can’t tell you how much I appreciate your offers!

The car actually burns almost no oil (about a half a quart every 1200 or so - according to the p.o). As far as a compression test, I haven’t done one yet. Prestige (eh), was the informer of the bad news Scott. The bottom end sounds very tight, but I am just starting to get some lifter tick, but only when the car is hot. I unfortunately have no record of the rod bearings being replaced, and by the condition of the rest of the car, I would imagine the answer would be ‘no’. I am using 20W-50 and a K&N filter (when I got the car it had a Bosch filter on it). The oil came out shaving free as well.

I have put all of ten miles on this thing since I got it, but it was basically free (long story), so I'm starting from zero with no PPI and a seemingly extremely poor service history (I do have a receipt for all the belts (no tensioner although) about 10K ago). After detailing out years of inept wax jobs, the car glows in the dark again, and really is very straight.

I was going to take it down to Eisenbud’s to see if he could find something, but it sounds like I should call you first! Thanks again, guys! You are the man Scott! Where can I get in touch with you? I am in the Arvada area.

JS

[Moneyguy1]

Sounds to me like you could at least verify the situation with a mechanical pressure guage temporarily screwed into the engine. I rebuilt one engine years ago that had near 0 oil pressure when warm. No metal shavings, just plain worn out bearings. There is not always damage to the crank under even prolonged low pressure unless the engine has been used under high speed/high towing conditions.The mechanical gauge will tell you if you absolutely have to pull off the oil pan.