torturebori

The mechanics tested the pressure. How I am not sure on that. But they assured the engine is holding the proper pressure.

I do trust them. So I will take their word for it.

SloopJohnB@mac.com

unless you have oil pressure issues. Besides, it involves dropping and cleaning the oil pan.
That being said, a car with 135K miles on it, probably running dino oil rather than synthetic for most if not all of its life, most likely has a lot of sludge and gunk in the oil pan. FWIW, our 2K4.2A6 was run on synthetic oil nearly all of its life; the only part maybe not was when it was new and before its first oil change when I insisted on synthetic I provided even though the oil changes were 'free.' At around 110K IIRC i dropped the oil pan because it was leaking/seeping and it was pretty filthy inside, even with bits of plastic from the cam chain tensioners I'm guessing. I had also noticed that even when I changed oil and oil filter the oil got black very quickly, within a week. After I cleaned the oil pan and reinstalled it, the oil stayed clean for about 3000 miles!!!

Long story short, it wouldn't hurt to drop the pan on a 135K engine that you have to change the thermal sensor anyway. I used "The Right Stuff" to reseal the pan…there is no gasket. Make sure you have an accurate inch-lb torque wrench and I also recommend using blue loctite to avoid those cap screws backing out. Any damaged threads should also be repaired with helicons.

Prospeeder

If you remove the oil pan. There are 2 tubes that move oil from the oil pump to the block. They have rubber orings that I have had on a few occasions fail and cause low oil pressure. Does it seem to only happen when the engines warmed up? Or just totally random, it could be the cluster itself, or the wire from the sensor to the cluster touching ground or going open. Or I have seen the sensor wire breaks right inside at the pin in the connector and it intermittently looses connection.

jcman

Prospeeder has given very good service and trouble shooting advice on the AVK 3.0 as he has worked on more than a few, this engine is not even close in design to other C5 power plants.

jseklund

Just some thoughts on this - if this is an independent mechanic, I've seen them have NO clue about the difference pointed out above between the pressure sensor and the temperature sensor. I've seen them replace the temp sensor when the pressure light is flashing on numerous occasions, even shops that claim to be Audi specialists. They then go to the sludge topic, and it's just a waste of time.

You can rent a pressure guage from Autozone and test the pressure yourself. I would do this. If your oil pressure is good, I would NOT be looking at dropping the oil pan to clean sludge.

I, myself, had an issue when I did this where I tested the pressure, it was fine, and I replaced the switch. When I got the car back together, the problem didn't go away. As soon as I would get over 2,000 RPM in the car, the light would trigger. This was because the switch doesn't trigger until you are over 2,000 RPM, and my connector was not fully seated on the switch. Take the electrical connector off, make sure it is on correctly, and reconnect it. It may be that simple.

the_duke

Who tested the oil pressure and what was the result? This is step one. If the oil pressure is not low then you have an electrical issue. Basic automotive troubleshooting techniques.

torturebori

It is a independent mechanic, Well he owns a shop here. He says it is not that level sensor, but that hasn't been changed. He did change the pressure sensor, tested the pressure, no loss of pressure, tested the wiring, got a replacement connector and pins. He now believes it is in the instrument cluster, but he did tell me that this is not the easy to swap out, as the coding for it is not so simple. He also said Audi would not recode a used cluster.

Any ideas where I can go from here? I was hoping to change out the level sensor as that has not been changed. I did order the part so I might as well do it.

But please if you have any ideas on the cluster it would be great. Or direction guidance.

Thanks

torturebori

The mechanic tested the oil pressure and said it was fine no loss. He did say they were sure it is the cluster, but to replace it is the hard part as coding for this is advanced and they cannot do it at their shop. And Audi told them they would not recode a used cluster.

Any thoughts, ideas or guidance much appreciated

SloopJohnB@mac.com

Unless the wiring has been damaged under the pan…like somebody decided they were better at engineering than Audi and decided to leave the bellypan off or damaged.
If the bellypan got damaged, inspect and repair any wiring damage and replace the bellypan. It's there for a reason.

Prospeeder

Remove the wire from the oil pressure sensor, ground it. Does the oil light now stay off or continue to come on, that will tell you if its wiring or the cluster at fault. You could then go directly to the cluster, and ground the wire as close to the cluster as you can and eliminate all the cars wiring and be sure its the cluster. The dealer should have no issue installing a used cluster.