fastex500

I have a 1997 D2 A8 with the 4.2l engine. 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 seal 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. The noise would go away over 2500rpm and followed the rpm of the engine. The noise also went away 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 rought idle, click/clack noise and rough idle with 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.

canabbage

Hi fastex,

Did you ever get to the bottom of this?

I have a quite similar issue in my TT's 1.8t.

- engine vibration (perhaps missing cyclinder(s))
- clacking noise from drivers side near fire wall but close to the block

The only additional symptom I have is that the clacking noise is much quieter when I depress the clutch. I thought maybe a thrust bearing issue but the clacking noise is in sync with the pronounced pulses of exhaust being pushed through the exhaust when listening underneath the car.

Thanks

canabbage

Twas the coils. I'm such a newb.. The clacking sound is gone and seems to have just been due to vibration induced by the missing cylinder.