Car was drinking coolant.
And overheating.
No white smoke.

Decided water pump or thermostat.
Replaced both with new ones.

Still doing it.

Decided to run compression test.

With injectors disconnected, all spark plugs removed, and throttle wide open, cylinder 3 (front front of engine) is spitting water/coolant.

Does that mean bad head gasket?
I always thought that would lead to 'white smoke'?

Is is likely that new head gasket will fix it? Or systematic for other defect?

Here is the video showing the coolant spitting:

AEB Spitting Coolant Video by KraftwerkTurbo | Photobucket

 

How long has this been going on?

Pull the head and take a look. Sure appears to be a blown head gasket. This is a fairly easy fix as long as you stop driving it and get it taken care of before other stuff gets damaged. Probably have some cylinder wall scoring too as well as some water in the oil. Cat damage?

 

No signs of foul play when warming up, only after some driving does the overheating start.
Did not run hot or dry.
No white smoke, no leaks.

Never had cat :-)
We are 'catless' household with 5 non cat audis (2x AEB, 2x 2.7T, 1x 2.8V6).

If chances are good its the head gasket, would start taking heads off now.
If good chance its the heads or block, would look for another engine (have 2 AEB bottom ends in unknown (not taken apart) condition, but NO heads.
And AEB heads are expansive, since all those guys with weakly 'low flow' non AEB engines are chasing the AEB heads. There should be a law against that!

 

I would have to assume its the head gasket, or a severely cracked head. that is a lot of water coming out of the hole when you crank it over. its possible the block could be cracked too. it sounds to me like you will be removing the cylinder head at the least

 

Head off now. Initial check: nothing obvious that I can see. Only surprise: found that a spark plug defauler is stuck in cylinder 3 (the one showing problems). No socket to get to. Locktite a spark plug into the defauler, will try to remove tomorrow.

Here are photos (as is, not cleaned).
1998 Passat AEB Photos by KraftwerkTurbo | Photobucket

 

What is a defauler? You have oil and water in the cylinders. Carefully clean the head and straight edge it if you can. See if it has noticeable warping. Clean the block, don't scratch it, and install a new head gasket and see what happens. Use new bolts. Torque in sequence. No visible cracks in the photos so it must be the gasket. Do a couple of oil changes if it runs maybe even Sea Foam it.

 

- in the old days, used to move a spark a bit out of the combustion zone. I only use them for tricking the rear O2 sensor when removing the cat. No idea why it was ever installed in this head

- Will clean up today, take the cams out and take the head to the local engine builder for inspection. See what the verdict is:

a) nothing really bad: new gasket, new bolts. Put back in

b) not bad, but could use a rebuild: get cost (rebuild and cost for gaskets, bolts, etc.). Weigh total cost against swapping other, lower mileage engine in.

c) Bad: get another engine and swap in.

 

aah, a defouler. Missed that. Good luck.

 

if this is hole #3, it would concern me. look closely for my circled area