I read another post about delayed oil pressure and a broken oil line. I am not aware of any oil lines, I don't have any oil leaks.

The oil pres gauge doesn't work, but the "light" does. When the car has sat for more than 10 hours the "light" will stay on for 10-15, the sound of the engine changes, BUT it is not "dry" to start.

Could this be a failing Oil Pressure Relief Valve?

 

Bump

 

It is the oil pickup tube that connects the oil pump to the oil pan. When I finally gave in and took the car to the mechanic, he said that the delay is due to the oil pump having to build up enough pressure to overcome the broken tube. I plan on dropping the oil pan later this week and will let everyone know if it solved the problem.

 

How did they know w/o dropping the pan?

Wouldn't the broken tube lead to a constant low pressure?

 

I'm very interested in this to, since i seem to have the same problem after i chaged all the seals on front off the motor. I posted a topic some month ago that it was solved, but it's not, it's only been better. I cleaned the OPRV.

I have had the oil pan down to replace the seal, but did not observe any broken pick up tube in there, so ???

I suspected the oil filter, and changed it to Porche original, but no change.

Maybee it's a buildup off old slodge deposit in the internal oil lines, that partially blocks the lined until the pressure has been on for this 15 sec. ??

I dont do anything about it rigt now since i'm restoring the Astrovan, but i'm interrested in a solution.

 

I don't know how they tested it but when I got the car back I did a test of my own. I took the oil filter out and surrounded the housing with a clear plastic bag. I had my brother crank the car and I timed how long it took for the oil to expel from the housing. Some listers said that it should take about 2 seconds, mine took about 15 seconds. Maybe if we overfill the oil pan we can see how long it takes for the oil pressure to register to see if it is a cracked/broken pick up tube?

 

ahofam123:

Let us know how this goes. Other's out there might get the probelm in the future, and then it's nice to have a solution to test for.

 

I've read about this problem a few times and have as a result noted that my oil pump pressure comes up very quickly. I donot ahve this problem. Still it is interesting. Some have mentioned the oil pickup tube as possibly being broken - I think they're on the right track. If I recall the oil pump gets its "feed" from a channel that leads to the mounting point for the oil pickup tube. The channel is open when/if the main bearing webbing is removed. So theorizing a bit here... I'm thinking that if you're losing your pump's prime, it may be happening because there is a leak somewhere along the channel. It could be a very small leak and have no other symptoms. Just my theory of what might be happening.

One other bit of trivia... I had my car up on ramps for a couple of days (for some AC work) and noticed that when I started the car I had the breif low oil pressure symptom that you describe (it lasted for maybe one second). So I'm kinda thinking that a high parking angle could cause the pump to lose prime as well.

 

"36. Sometimes oil pressure is slow to build or doesn't build at all after sitting. The oil pump must be resealed, but short of that, a new front main and special o-ring (900 174 049 40) must be installed to help the oil pump not suck air."

Tech Tips!

Chris

 

Now we're talking! I know I have a very small leak at the front seal because there is engine oil on the bottom front of the engine, but it loses only very small amounts as I check the oil daily, and only add 1/2 qt / two months. Which is also the oil change interval for my 80+ miles a day.

 

There is a connection...

 

Hey is that o-ring 900 174 049 40 the oil pump shaft o-ring?

 

hmm... have no idea - that came streight from the book - haven't seen this part

maybe someone with a parts book could tell us??

 

Just curious, do you guys also have the problem where - after driving for 20-30 minutes .. the "low oil pressure" light will flicker when at idle?

 

i will find out today for ya- only had the car for 24 hours so far