'04 A6 3.0 - Red Oil Pressure Light On and Off
 

I have a 2004 Audi A6 with ~74500, had it almost a year, bought at ~68000. About 3 months ago I was getting the oil pressure warning light (it would come on and chime several times then in a few minutes turn off). Had it checked out, it was the sensor and I replaced it and the oil (~72000).

In the past week I've seen a few issues:
1. Oil pressure light turns on, chimes once, turns off
2. The ESP turns off randomly.

I took it to the dealer and they went over everything and said they had no faults aside from "... fuel too lean" and said that caused the ESP to turn off and I should replace the MAF. As of this writing I followed these steps: http://hubpages.com/hub/clean-replace-vw-audi-maf-diy and now the ESP light is off and the car seems to run smoother.

Audi said they checked the pressure but could find nothing out of the ordinary also said I should use an Audi oil filter. I have a Mobil 1 filter and I use Mobil 1 synthetic 10W-40 High Mileage. One thing I did notice is that the dipstick is cracked which I'm looking to replace, but I'm guessing doesn't really mean anything.

Since cleaning the MAF oil pressure light came on again a few times, chimed 3 times, and turned off. I'm concerned that there is something else going on, but if the dealer says nothing is wrong, I feel I'm at a loss.

Has anyone seen or had this issue? Anything that you did? Could this be an oil or oil filter issue?

I did find the following posts, could it be sludge or just cleaning the pan/screens? Is anyone else using Mobil 1 10w-40 HM with/without issue, is that wrong (I live in CT).

https://www.audiworld.com/forums/sho...pressure+light

https://www.audiworld.com/forums/sho...pressure+light

Thank you in advance,
Sandro

"... fuel too lean" is very likely refer to MAF.

Instead of cleaning MAF, replace the MAF sensor. Sometimes it still won't work just by cleaning.

Thanks bigdadi, if it throws the lean error again I will replace it. So far after I cleaned the MAF it seems to be working without issue. Now if I can only figure out this "pressure light" problem.

It is possible the new sensor you had/put on has failed. The only way to be sure is to monitor oil pressure separately with a mechanical pressure gauge..tap into the oil pressure where the sensor is and see what's what.

If you have adequate oil pressure you replace the sensor again.

If you DON'T have adequate oil pressure you drop the pan, clean it and the oil pickup screen and probably replace the oil pump, put it back together again with thick oil in the pump, fill up the sump, spin the engine over with ignition disabled until oil pressure comes up, enable the ignition, and run the engine.

I had a similar problem on my 2002 3.0. The oil pressure light would come on randomly but the pressure was good. One of my mechanics thought it was the oil pump but my smarter mechanic said no way and told me to check the oil pressure sensor. It turned out that oil was leaking onto the sensor and getting into the electrical connection. I cleaned the plastic connection piece with a degreaser and let dry thoroughly and also bought a new sensor ( although I am not sure if a new sensor was needed since it may have just the oil in the connection). The part was cheap and purchased at autozone iirc. The sensor is easy to access from the front with a long extension. I think I also removed the driver side headlight for better access.

This also occured around the 80k mark and the issue has not returned at current, 126k.

TWB

Also try using 5w-40 M1 Turbo Diesel or O-40 M1 Euro formula. Both Audi approved.

I just pulled the skid plate off, cleaned the sensor and connector with some rubbing alcohol and let dry. It looked rather clean inside and out but I'm hoping that's the problem. I also saw the connector looked like it was showing some of the wire so I took some electrical tape and covered it up. (see pics)

I drove the car for about 15 minutes, got the car up to temp and no error light. Knock on wood.

I'm going to drive the car around without the plate for a few more days in case the light comes back on and if that's the case I'm going to have to drop the pan and see what's going on. I also bought some 0w-40 M1 Euro for that work.

Thanks again.

Looks like I have to take the pan down and see what's going on as the light came on several times today.

I did some searching and couldn't really find much on replacing/removing the oil pan for a 2004 a6 3.0 quattro. Does anyone have any DIY tips or notes?
I can do this I just want to make sure there are not "gotchas" that's I'm not aware of...

Things coming to mind are:
should the bolts be torqued to a spec or does that not matter?
Gasket or sealant? Special kind/brand?
Do I need to do anything special once I put the pan back on? Can I just put oil in and turn the car on?

Thanks in advance.

I used "The Right Stuff" on my 2K4.2A6 oil pan and it worked fine.

Bentley says to cut the applicator tip to make a 1mm hole to apply a bead no thicker than 1.5mm around the lip of the oil pan and around the inside of the oil pan bolt holes. Thicker than that can allow the sealant to get inside the pan and clog the oil pickup (???!!!).

The pan must be installed within 5 minutes of running the bead...so don't take all of your five minutes to run the bead!!!

Install the pan with bolts finger tight, then diagonal-tighten then to 5 NM. Then final torque them to 10NM.

Let the sealant set up for at least 30 minutes before filling/starting engine.

I let mine set up overnight, I had other things to do.

DID YOU ACTUALLY CHECK THE OIL PRESSURE WITH A MECHANICAL GAUGE?

If you didn't you have no idea whether you have an oil pressure or sender problem.
Dropping the pan can be useless although a fun exercise in cleaning sludge out of the pan.