Need some help, or any advise where to start!

I have a 1997 D2 A8 with the 4.2L engine (230k). It has had the clasic oil cooler leak for the past few months, but I have paid attention to oil levels until I could get the seals replaced.

As soon as the cold weather hit I started getting a squeal/clacking noise from the engine compartment. Almost like a loose belt, but with a bearing like click which followed the RPM's of the engine. The noise would go away over 2500rpm or after the engine warmed up. I thought it may be my transmission pump as this is a common fault on the D2's and the noise seemed to come from the drivers side of the engine near the firewall, but then after a month or so, I got a rough idle and a check engine light with error codes on cyl-7.

I immediately parked the car and pulled the plugs. Everything looks good, other than warn plugs. So hoping for an easy fix, I changed the plugs, swapped the ignition module for a new one and swapped the #7 coil.

Re-started the car and get the same rough idle, click/clack noise and a small amount of blue/white smoke on start.

I am guessing it may be a valve, but wanted to get some feedback before I pull the heads.

 

sounds like you either have a leak of coolant into your cylinders (very unlikely) or you have the same problem I did before which ended up with me having the fuel filter, air filter, and coil packs swapped. Have your mechanic check the jet suction pump and PCV (N75) the JSP leads to. The diaphragm in my PCV had failed causing a major pressure leak that resulted in serious rough misfiring and eventual shut down.

 

i'm feeling a lifter **** the bed.

very common on the 4 cyl esp. with that kind of mileage and as they are the identical part for almost all vag cars with hydraulic lifters i would look there. If i recall correctly you can test the bleed down on a lifter by only removing the valve cover to get access, i'm sure you can find some post somewhere for any vag car.