Against my better judgement I bought a rough running 99 A6 2.8. It was a good price.... Just a lot of little problems, and one Big problem. Engine is reading 0 compression on cylinder 2. Wont stay running unless I smash on the gas. Any Ideas would help. I was thinking worst case the cylinder is self is messed up and I would just do an engine swap. I was also thinking the coil pack/distributor could be bad. Bad Plug or wire? I'm open to suggestions. Thx

123xxx Miles
Engine Code: AHA
Trans. Code: DPT

 

It could be possibly due to damaged piston rings, which would not be allowing to generate enough compression. This will also cause the exhaust smokey. Apart from piston rings, this could also be due to damaged intake or exhaust valve, allowing the air to escape and not generate enough compression.

 

No way around it - if you have 0 compression you're looking at an engine overhaul or swap.

 

Thanks guys.... that is what I thought.

 

Took the time to Hook up the VAG-COM and did a scan... Cleared all the old messages and ReScaned. There is a bit of a misfire but the gas is a few years old and i'm sure the plugs and wires need replacing. The only thing that concerned me was the throttle position. Had to still keep my foot on the gas or it would die out Thinking the ECU needs replacing? here is the code.

18264 - Throttle Potentiometer (G69): Error Message from ECU

P1856 - 35-00 - -

 

Use the vagcom to do a throttle body adaptation (instructions in the ross-tech.com Wiki section. That may alleviate the throttle problem.

 

Thank you for the throttle info it is very helpful. I found an engine for it, 1460.00 from AdvanceAuto it comes with a 1 year warranty on all parts Granted it has 87000 miles but I am under the assumption that the engine was tested well. I also found one on ebay for 1500 make an offer/free shipping, with 39,000 miles on it, You never know what you will get off ebay, especially when its high dollar, plus the seller said it doesn't come with extras. Seems like I should take the one from Advance, better deal, comes all-in-one, with a warranty. Yes less miles would be nice but I'm not taking the chance I get screwed online. I'm a physical transaction kind-a-guy anyway.