Gregg K

I changed the oil and filter. After 250 miles, the low oil level light came on.
I'm not happy, needless to say. I"ll just leave it at that. Now, I'll follow up with pictures of soot in the tailpipe. But here's what I know. I used Castrol 20-50, altho that's not really important. What is, however, is that the PO did the compression and leakdown which both came out looking good. About 160 psi. compression.
I smelled oil on my latest drive, but didn't think anything of it. I know this is a problem that can't be solved on a forum. But I'm just checking to see if anyone has any ideas. I've tightened the oil pan bolts. There are no leaks as of my last drive. There is black soot in the tailpipe, but I think it's fairly normal.
This is for the '89 GT. And I'm posting it even if this causes a problem when I go to sell it. I believe in telling the truth about things.
I don't know how many quarts it was low. But I pulled the dipstick with the nose pointing downhill, and there was almost no oil on it.

worf928

Gregg, if there was no oil on the dipstick then it was about 2 quarts low. Based upon what you posted I would not yet jump to conclusions. My '91 typically uses 1 quart of oil for every 600 miles of driving. On the track it will use roughly a quart per 100 miles.

Where those 250 miles easy or hard?

worf928

Also, I know you said that there were no leaks. You are sure? You've checked in the valley between heads under the intake? You don't get any smoke/smell from the engine compartment?

Just checking...

Erik - Denmark

Hello Gregg,
Now you have good reason for scratching your hair

- Did you remember to ad extra oil for the empty filter?
- How was the condition before the oil change?
- If you are sure the engine is not leaking, then there are only one possibility, the engine 'eat' the oil - then make a compression and leak down test and you will find the reason

Regards from Erik in Denmark

MikeN

First of all don't panic.

Park the car on a level surface and fill oil to the proper area on the dipstick.
Then check and monitor the oil usage.

My previous '89 S4 almost used no oil, while my GT will probably use about a quart every 1000 miles give or take. Both were/are low mileage examples in perfect health.

With the GT you typically spend a lot more time in the upper RPM range then the average 928.......that is what I attribute the extra oil usage to.

Once in a while upon restart when my GT is parked on a steep incline (nose up) I will get the low oil light, but all is fine when I'm on a flat
surface again.

Gregg K

On edit- Hey, I just checked the oil level. Something I should have done before posting this thread. And the level is a lot higher than I thought. I used only a half quart or so, in the last 250-300 miles. So, it looks like that oil level light comes on early. AND, it looks like I should have given the car s few more minutes before checking the oil level.
Looks OK.
Thanks for your replies.





Yes, I did fill the filter, fully. Good question.

And the valley does show signs of a leak. It's filling up those two areas in the front. But I can't blame what I see as being the cause of too much loss.
The PO said one of the breather lines is cracked. I can't find it.

I drive hard enough that I can imagine using more oil than typical. But a quart per 100 miles!!!! Maybe a GTS, but not a GT. You know, shorter piston skirts, yada, yada.

The temp II sensor always has oil on it. I can clean it off, and later it's oily.

worf928

Gregg, next time you are out driving watch your oil pressure carefully. The reason I write this is because I've never had a problem with the oil settling into the pan quickly. Your concern that you should have waited longer before checking the oil is a bit worrisome. Perhaps you have oil staying up in the heads longer than it should - blockage?
Good luck. It might be that you will have to loosen and lift up (about an inch) the intake in order to find the offending line. Tony has a write-up and there's also a massive write-up on the OC site. I prefer the latter since I wrote it
On. The. Track. 1/2 quart per session.
Oil filler neck gasket. There are also three breather lines (if memory serves) into the neck on the '89GT.

Gretch

My 89 GT uses almost no oil between changes, which due to the time element are usually around 5000 miles. We will see if that changes after the SC installation..............

Perhaps the best thing is to fill her up and then check the oil every 100 miles. This way you can be certain weather she is eating it or spilling it.

Gregg K

Shoot! Gretch, you would say that. The tailpipe is sooty. But I do not see blue clouds. And I would. I check more often than 100 miles.

David, I always have my eyes on the oil pressure guage. Unlike my '79 which pegs on high, always, the GT drops with lower rpms. It sits on the 5 bar line when running over 3 grand, but drops to 2 bar when below 2 grand or maybe a bit slower. But I don't see what that has to do with anything but perhaps main bearings.

Yeah, this thing's using way more oil than it should.


I just remembered- plugs will tell me a lot. I guess it's time to pull plugs. Geez, this ain't like my Honda 110. But then my 110 isn't like a GT.

Randy V

You ever hear the story about the boy who cried 'wolf'?

Gretch

Well, I happen to love black on black 89 GT's. If you don't want it I will trade you one of my toys for it. You got a Harley?

worf928

Good. If you were seeing a rise to 5 then decline to 3 or 4 it might indicate oil staying longer in the heads than intended.
Or a dirty connection at the oil pressure sender.

drnick

my 88 uses more oil than my 86, i have noticed. my thought is that its being vented from the crankcase and burnt via the intake but im not too concerned, it goes soooo well that i am absolutely certain there is nothing wrong with it, and, more to the point there are so many posts about oil lifting and 'excessive' consumption that this must be normal. one day i may revise the crankcase breather system or add a dry sump!

Gregg K

OK, I think it's time to mention that this car is AWESOME!!!!!!!
And it's growing on me. I won't mention that there's another '89 GT about to come on the market. So if anyone wants one...
Today I drove the Avenue of the Giants. Did I mention this already. It was a BLAST! So, I'll stop worrying about stuff and just have fun.
Real Porsches have V engines!

UKKid35

Gregg

Don't worry about your low oil pressure on idle, it's almost sure to be your rear camshaft plugs:

http://members.rennlist.com/v1uhoh/nasty.htm

I was relieved to see mine had deformed and fallen out as I suffered the same problem.