velns

Hello.
What could be wrong? Here are symptoms:
1. Takes a long time to get normal oil pressure in mornings
2. In operating temp, pressure shows 1,5 or even 1. sometimes pressure led blinks. When driving pressure seems to be normal but in idle ....

Today I got the most strange thing, pressure did not rise even when I was driving, just red leds and shows just 1 from 2,5 as usually. And there was knocking sound from valves I think.

I cheked 5 times for oil lever and it's normal, cars temp also does not rising up. Oil is semi sintetic Viso 3000 and 7000km after last change.

Can it be oil filter? Or I'm in more serious trouble?

Kevin Baker

First thing to check is the Oil Pressure Relief Valve. It looks like a 24mm bolt that is below and to the left of the oil pressure sending unit. Remove this and check its operation. You have an 87 so you SHOULD have a one piece type. The piston should travel with moderate pressure. There should be an O-Ring at or near the end. For more details and diagrams, try doing a search (in this forum) on "slow build oil pressure" or "delayed oil pressure" or "oprv". I wouldn't operate the car with the valves making niose.

Another possibility, have you recently had the crankshaft pulley off? If so, check to be sure the bolt is tightned to 150ft/lbs of torque (not sure of the newton/meter spec).

sweanders

If it's sort of a klanking sound sound you may have spun a bearing..

RajDatta

He said valves, not a knocking sound from the bottom end . No need to give someone a heart attack .
I would check the oil pressure relief valve first and then check that the crank bolt holding the pulleys is torqued to 155lbs/ft.
Sounds like too low an oil pressure and the oil is not getting to your lifters and hence its your lifters that are making that noise. I doubt it, its anything else. How many miles on the car?

velns

180k miles. It hapnd in two days. Fistly just noticed delay in cold mornings till no pressure at all.

Sorry for these dumb questions, but:

Where can I find oil pick up line and oil pressure sending unit?

Heh.....

RajDatta

Ok: for the oil pressure relief valve, take your passenger side from wheel off, remove any engine covers from the bottom. Look for your oil filter hosuing and you will see on the back of this housing the oil pressure sending unit. It will have 2 wires connected to it. Next to it you will see a 24mm bolt. If you remove this bolt, you will see it is a long cylinder with a spring loaded section. This is your oil pressure relief valve.
Oil pickup is in your oil pan. I would avoid looking for that first as it will involve removing your oil pan.

velns

aaahhhh...... heh......... okey, thanks for your help. Will wait for some week to check because it's -5C there. Too cold to work under car and I dont have warm garage.

If my oil pickup tube is bad, may it cause oil leak? Guess that no if it's in oil pan.

Can it be just bad dirty oil filter?

velns

How do I tell that my oil pressure relief valve needs to be replaced? Rust? O-Ring?

Dal Heger

If you have klanking then you spun a bearing. It may sound like it's coming from the upper end, but it's really hard to pinpoint that noise. If you've been running your car with 1 - 2.5 bar oil pressure then you have spun a bearing. Don't start it again, don't drive it, take it to a good porsche mechanic that knows 944s and have him look at it. Then be prepared to spend a few grand on getting a new set of bearings and the crank fixed.

Dal.

special tool

Hey Velns - you shouldn't even start that car, nevermind waiting for a warm week, dude. No, it probably is not your oil filter (if it is black) - you have no pressure and a clank sound, moonbeams and fairydust are not going to fix your car.





-Lutjen

Peckster

That morning oil pressure problem was a warning that your oil pressure was dangerously low. It's probably why your engine is knocking. The fact the oil is 7,000 km old doesn't help either.

Valves don't knock, they tap. If you have a knock, that's a probably rod bearing problem.

Like the guys say, stop driving it now. Pull the oil pan and have a look.

Kirby2

You and I are in the same predicament. I recently bought a 951 and inherited the problem. I have it apart and the inside of the engine is covered in little metal flakes from the spun bearings. It seems that the bearing metal flakes will clog the oil galley that feeds the hydraulics in the cam followers, you get an added knock from their poor function.

Let's stay in touch on this issue! Misery enjoys company.

velns

Hmmm, no I don't think it's rod bearing, because this sound started when there was low oil pressure and ended within normal oil pressure, the sound was only in idle, sounded like old audi, more like valves without oil. I will start with oil pressure valve.

Really hope that it's not so bad as you all mentioning.

Thanks for your help.

velns

ahhhh.. I don't know the difference between knock and tap and grind sorry for that. Knocking was slighty noticable and very good noticable with 1 bar pressure.

Perry 951

Rod knock is much more noticeable at idle because the oil pressure is down and not providing enough pressure to keep a good thick oil barrier.

1st things first, remove the oil and filter, then cut the casing off the filter (carefully) and check for metal particulates. If you have flakes, you found bad news. Check the oil you drain out as well.

I'm leaning towards an oil pump problem here. Triple check the tension on the crank bolt. If it is tight, slowly rotate the motor over and listen to noises on the pump side. I have heard of the innner races of the pumps opening up enough to drop pressure.

Your car is an '87, so you have the ever faithful 1 peice oil pressure relief valve. These typically do not fail, unless shavings from rod bearings get in and lock it up.

Again, keep it easy to diagnose, go with the simple stuff. Oil, filter, crank bolt. Check all that and let us know.