Gulliver

( I did do some searching on here before posting this, and I know similar problems have been addressed, so I'm sorry if this was already covered. )

Hey guys, drove the '87 944S (stock-140k) home last night with no issues. This morning I have warning lights and no oil pressure- light is on at the bottom of the gauge. I believe it, too- it'll start to tick after running just a moment. So, I of course turned it off. It's full to the mark with clean oil and no recent issues.


My question is, what do I do next? I'm under the impression that it's likely the OPRV, but is there a way to check it's operation once it's out? Could I just re-seal and reinstall it?

I do know how to use an external oil pressure gauge, but I'm believing the in-dash one.
So, in what order do I need to check the sending unit, OPRV, and other things?

joonas

I would do following:
1. Check crankshaft bolt. Torque to 210 Nm or 155 ft-lbs if it seems loose.
2. Pull the fuel pump fuse so the engine would not start. Crank for 15 sec. if no oil pressure move to next step.
3. I would check if the pump moves oil at all. I would take off oil filter or oil pressure sender and crank the engine to find out if any oil comes out.
If none I would think it is cracked pickup tube.

4. You can always remove the OPRV and see if it is stuck open or sticking if you push the OPRV piston inwards. Maybe you can reuse the old OPRV O ring if it is not damaged.

Oil prssure takes some time to buil so if you want to check crank for 15 sec. If you have external oil pressure gauge I would use it for testing. Those senders have failed or giving wrong readings.

931guru

Good solid approach to the problem... +!

Gulliver

Thanks guys, for the help.. I feel like I should clarify- I have been driving it regularly with no issues. It hasn't been apart in any way, had an oil change, no work done to it whatsoever. Drove fine one day- next morning, no oil pressure.
If the OPRV is stuck open, does that cause a no oil pressure issue?

J Berk

Not that I want to encourage you start it up again...but are you sure the the ticking is not just the injectors? They do make a definate ticking sound.

If this just happened...after bringing the car in for an oil change...is it possible that the wire to the oil pressure sensor became disconnected?

Just seems too coincidental....

Gulliver

No, there was no oil change- haven't had any recent work at all- that's why it was confusing to me. Can' figure why a sudden random condition?

J Berk

My bad !

I saw this:
And when I read it the first time, I saw "HAD AN OIL CHANGE".....now I get it !

Gulliver

Sorry- that was worded wrong. No work at all has been performed this year. It's been driven regularly without issue.

I am curious as to what condition could cause this out of the blue with no other apparent failure.

IGROWL

Gulliver,

How long have you owned your Porsche? These cars are 20 something years old. Things sometimes suddenly go bad for no apparent reason. Did you check the steps that joonas stated above? You need to run different tests to eliminate the good parts and find the part that failed. Clarks-Garage is a good resource also.

Gulliver

I have had this one for about a year. It's my 3rd 944. I'm very familiar with all the known problems/issues with these (and have learned the hard way on most).

I've just never had a "no oil pressure" condition and suspect the OPRV, since there's been nothing apart or serviced recently. Will faulty oil cooler seals cause this as well?

joonas

If it is oil pickup tube it has nothing to do with service. You could also check it first but other checks are easyer to do. If you do not find oil in your cooling system then oil cooler seals are fine.

As mentioned above look Clark's site http://www.clarks-garage.com/shop-ma...ure-index3.htm

I have not looked engine block that closely to find out if it is possible to have no oil pressure if OPRV is stuck open.
One thread about OPRV http://clarks-garage.com/phpBB2/view...k+open&start=0

It can be anything. You just need to start ruling out things or take it to the shop if you cannot handle the pressure or lack of it

IGROWL

I have one experience with the OPRV and that is when it got stuck closed. It was after a oil coiler seal replacement. It wasn't aligned with the tool before hand. It blew the seal off the oil filter after the car was started and run for a very short period.

Why do you suspect your oil cooler seals are bad? Do you have a leak?

Did you try the steps above that joonas recomended?

Gulliver

Ok, crankshaft bolt is tight, torqued to spec. It wasn't loose.

Now any ideas what size socket fits the OPRV? My 22mm is as large as I have..?

Gulliver

RESOLVED

tiny piece of metal (?!) in oil passage hole had the OPRV blocked from sliding. Looked about like a baby's pinkie fingernail clipping-a little shaving from something stripped is what it looked like. Not good, but all else looked good, cleaned and reinstalled it, 5 bar on cold startup, as normal. Thanks for the help guys!

Now I need to change the oil and hope I don't find more..

John_AZ

What weight oil have you used in the 944s and now the 924S?
When you drain the oil, place a thin rag over the bucket and cross your fingers.

GL
John_AZ
1988 924S 60K + 1987 924S 113K