V6 Infamous for oil problems?

[eastcoastaudi]

I read those pages. Good info. I guess its either a faulty oil pressure sender, a clogged passageway to the oil sender, or a bad oil pump..which I would HATE to see....or even worse spun mains... This trouble shooting stuff is not my favorite because it all involves too much work for potential dead ends.

[Lago Blue]

only correctly identifying what is the actual target. Trouble-shooting is entirely purposed to try to avoid the extra work of those dead-ends. It therefore may not be helpful to simply guess. What may work is spotting the root cause(s?) of the trouble before pulling the trigger. The kinds of things that others have done here successfully to find the source of external oil leaks are:

a.) park the car such that you can get under the engine (wooden blocks under the tires, whatever is safe, etc.)
b.) remove the belly-pan;
c.) thoroughly clean the outside of the engine, top and bottom, of oil with rags, brushes, solvents such as Brake-Kleen, etc.;
d.) run the engine at idle in place until the leak is first observed.

The above may have to be further pursued depending if the leak can be observed without more engine dis-assembly; or not. The engine may have to be run at higher speed. But, that you have external leaks should perhaps best be first pursued while the engine is still together, operable and; observable while leaking.

As the oil pump is capable of providing a great deal of pressure (the AAH max. pressure relief valve opens at 16 bar / 232 psi!), that you have evidently both external leaks and low indicated pressure may be related; or not and your bearings, and oil pump may be fine, and major engine dis-assembly unwarranted.

The cause(s?) to your issue(s?) may be of, but not limited to; the following list (from the easier to the more difficult):
- oil fill cap gasket;
- the above mentioned tabbed O-ring;
- cam-cover gaskets;
- a sensor obstruction
- a sensor passage-way obstruction;
- a sensor failure (mentioned by turbo510);
- an actual sensor leak;
- oil pump attachment bolt(s?) loose;
- an oil pump body to block gasket leak;
- an oil pump failure (mentioned by maineman); or
- an oil pressure regulating valve failure.

In the course of going through this shopping-list you may also uncover your lack of pressure indication issue. It may be something to do with as you say "seem to be saying the same story", as they share a common manifold 9see illustration below); or something like this:

http://forums.audiworld.com/showthre...t=oil+pressure

More information is available. I think all of these topics have been discussed if you include all the model forums here that share the 12v:
- Audi 90 / 80 / Coupe quattro / Cabriolet Discussion
- Audi 100 / A6 (C4 Platform Discussion;
- A4 (B5 Platform) Discussion

For instance see Autinado16's excellent write-up on his oil pump saga of which this is but one post:

http://forums.audiworld.com/showthre...light=oil+pump

What year is your 90?

[eastcoastaudi]

So I ran the car with a blinking Oil light for about 1000 miles. Then I decided to dig into it, I removed the valley pan and replaced the gasket. I changed the oil with some castrol GTX 20-50 and a larger filter. Oil pressure is 4 bar on start up, 2 bar at idle after warm. No oil light. Presto. However NOW I have a very high idle around 1,300 rpm and as soon as I go from cruising to accelerating the car gives a big jolt and falls flat on its face before continuing in what feels like "limp" mode. I can get more information if somebody is willing to help?

[grillage]

Has it run right at all since you did the valley pan?

The first time I took my throttle body off my car I neglected to replace the wiring harness that attaches to the Throttle Position Sensor. I had similarly weird results.

[eastcoastaudi]

No it hasnt run right since I got it all back together....I just bought the car with the oil pressure problem so Im assuming its something I did. It ran fine before.

[grillage]

Stick your arm down there and check the TPS - you can put it back without taking anything apart. Could be that

[eastcoastaudi]

So I just did exactly what you said. The TPS plug had backed itself out because when I put it on there the first time I must not have set it to click. I had forgotten how painfully slow this car is. Now all I have to do is get on some performance upgrades and tighten up a couple clunks in the front end. SAWEET.

[eastcoastaudi]

And Thank you for the help.

[grillage]

Originally Posted by eastcoastaudi

And Thank you for the help.

Thanks! I feel like a genius for calling that.