stigg

My allroad started leaking coolant. It happens after driving, usually there is a square foot or so spot some time after the car is shut off. Once only I have actually waited to see where it leaks and the coolant was trickling down the seam between the engine and the tranny, likely from the driver's side. Recently there was no leak for a couple of days but this morning again, I found a spot.
Today I took off the Y pipe and could see the hoses and the pump but I don't see any coolant residue there. I'm ready to take out the manifold but have doubts if this will reveal much. I did the search about the turbo lines leaks fix but looking at the space there I'm at a loss how to get there. I'm thinking about pressurizing the system to possibly detect where it leaks. What is the max pressure I can apply?
What would be the best approach? Thanks

MrKid

A pressure test is the way to go, if you have the equipment on hand. I would check the hoses from the reservoir, and the reservoir itself for leaks.

stigg

Never noticed any coolant up top. This would be quite obvious if the leak was there.

MrKid

You said it appears to be coming down the seem between the engine and tranny. It is traveling from somewhere up top, and the leak source is NEVER obvious. Especially will engines packed in as tight as these are. The lines from the reservoir run to the back of the engine. It's worth checking.

stigg

Ended up rigging up a pressure test yesterday and did get some seeping from the aux pump, the pressure went down, very slowly.
Today I took off the manifold, removed the pump and made a bypass. Changed some deteriorated vaccum lines as well. Pressure tested again, did not see it dropping after several minutes so hopefully this might work.
However, I have another problem now. The car revs up and down, check engine light came up and after checking the codes I got random multiple cylinder misfire, P0300. I am at a loss what might have gone wrong, feel real bad now. Today is too late to go back and I'm drained. Any ideas what I might have possibly done?

MrKid

Vacuum leaks can cause a misfire. Start with double checking each one you changed, moved, touched, or even looked at funny. The vacuum lines are crap in these cars.

stigg

I concluded that my old gaskets were the reason for what appeared as a vacuum leak. Today I got new manifold gaskets and went through the whole procedure again, checking everything. All looks ok, no parts or plugs left :-)...
The engine runs the same, at around 1400 rpm or so, revs dropping at times. The vacuum is stable but reads only 14-15 in-Hg, spiking momentarily when revs drop. This vacuum looks ok at this rpm but what is causing the high rpm?
Tried to locate vacuum leaks, could not find them so far.

MrKid

I just finished fighting with the misfire issue. I decided to go with the 2.0 coil conversion. Take the car for a drive and try to force a specific misfire. Mine would only misfire under heavy throttle, at higher rpms. If you can isolate it to a specific coil, try swapping that coil for another. If you have multiple coils on the same bank, swap the ICMs.
After playing this shell game, I couldn't isolate either, so I replaced the entire setup. I didn't get the entire "swap package". I bought the coils and Toureg spacers, and spliced all connections. Cost less than $250, and the car runs great.

stigg

Once again, a simple explanation of a problem wins it.
Removing the pump I removed the whole intake, with the throttle body.
After, I probably got some vacuum leak which threw p0300 DTC.
This I fixed by re-installing all the stuff with new gaskets.
The major issue, and I guess not many people know that, is that if TB, or ECM, loses power, it needs to go through what they call adaptation procedure. It is after all, a drive-by-wire system, no mechanical connection between the pedal and the throttle. (Remember this when you hear somebody has "hijacked" the plane...)
I spent several hours going through the manual and finally found it.
It described symptoms matching mine exactly. I tried auto-adaptation but since I had DTC the process was not successful.
Today I erased the p0300, switched the ignition on for 6 seconds, started the car, got steady idle at 650, vacuum 18.1 in Hg, no codes are showing up.
Did not go for a drive yet but it looks like all right.
Hope this helps somebody.