rob76turbo

I had a pretty serious issue happen to my car today at the PCA Mav Region DE.

Ran the two AM sessions and everything seemed okay with the car.
Decided to run "Charity Laps" at lunch as this is a good way to drive the line at a reduced speed. Anyway that when the problems started.

I was going at a very reduced pace in a tight right hand turn when I noticed my oil light flash (the one with the "!" at the top of the dash). It happened very fast and when I looked at the oil pressure it was at 5. Then keeping an eye on it, the oil pressure started to fluctuate between 5 and about 2.5. I drastically slowed down to keep an eye on the pressure. As I continued the lap (once again now going very slowly) the pressure started to fluctuate even more. Finally staying at around 2 and occassionally going back up to 5 for a couple of seconds before going back down to 2. Then the noise started, it was a grinding sound from the motor. It would go away when I came off throttle. I was able to more or less coast back to my parking spot. By now the grinding sound was go on all the time (at idle too). I turned off the motor and wanted to cry..... The engine oil was full and clean, but it sounded like there was no oil getting to the top of the motor (in the area of the head). The condition of the cam belt is good, so I see no issues there.

So after talking to several 944 types at the track, I came away with the following potential issues.

1. Maybe the bolt on the main pulley crank had come loose (or was loose to begin with). As I understand it, the bolt needs to be very tight to create a good seal so that the oil pump shaft can spin. I think this is unlikely.

2. The nylon pads under the Vario-Cam chain have desinagrated and worked their way down into the oil pan and have clogged the oil return lines. Maybe..

3. Or the oil pump has failed. Probably...

Some good news out of this, some friends had trailered their car to the track and put my car on the trailier for the trip home, saving me big bucks on a tow.

So any ideas? Has anyone had this happen before or does that sound familiar? Any ideas would be helpful before I start tearing the engine apart looking for the cause and the fix....

Thanks in advance.
Rob T.

luckett

crack in the oil pickup tube?

rob76turbo

Chris, that was also one of the ideas of what the potential issue is. Motor has 88K miles, would this be common or does it happen at this milage?

luckett

I happened to mine with about 160K miles. High G loads would probably accelerate this failure.

RajDatta

The main crank bolt and oil pickup would be my 1st two options as well.
Oil pickup tube can crack from misaligned lower bs belt/sprocket. Even if the problem was found and resolved, it could still cause fatigue in the pickup tube and over time it can crack.
Chances are, this is your culprit. No/low pressure oil is going to variocam tensioner and thus you don't have full tension on the chain.
Good luck.
Raj

rob76turbo

Yes, I plan to put on the Flywheel lock and check the bolt. Does anyone know the correct torque?

Then is that is not the culprit, I will pull the oil pan and take a look at the oil pick up and return lines. I will also pull the top off the head and take a look at the VarioCam pads too.

RajDatta

155 lbs/ft
Raj

Julian Allen

Might check the sending unit also--fluctuations like you report could be due to a bad rheostat in that unit. Easier/cheaper than pulling the pan.

rob76turbo

Julian,

Thanks, just had the sending unit replaced less than two weeks ago. I am wondering though if the shop could have done something else (by accident...) that set this issue off when they were replacing the sending unit?

rob76turbo

So I am going to run my Audi A3 (2.0T with DSG) today at the track.....

rob76turbo

Does anyone know of a DIY about droping the oil pan? I heard that it can be done while the motor is stil in the car.
Oh, BTW, my 200th post. Not anywhere near some of you guys, but a milestone for me!!

rdhayward

With the engine in the car, you'd have to get the crossmember out of the way.

RajDatta

Julian, that could be a good possibility but he said he heard mechanical sounds. If the sending unit was bad, it would not cause the engine to make machanical sounds, correct?

Raj

RajDatta

You will need to have an engine hoist to suspend the engine while you take the pan out. There is a hook on the top bs housing an one in rear of head to suspend engine.
You must drop crossmember and disconnect steering rod to do this.
You can remove the entire crossmember/suspension in 1 piece but make sure you have additional help.
This would be the easiest way but would require extra hands.
Remove rear castor block bolts into body
Remove steering rod bolt to steering rack
Disconnect PS lines
Remove brake calipers and tie wrap them to body
Remove front swaybar from body
Remove four 13mm bolts holding strut tower on each side

I might be missing a step or two but that is pretty much most of it.
Raj

Julian Allen

Maybe a couple more questions will help. It has been my experience that sorting out sounds from within the car is pretty difficult.

Why did the sending unit get changed recently? Have you checked the connections at the unit (two wires)?
Is the car a daily driver/rare track use or does it see an event every several weeks?