2009 Audi A4 Quattro 2.0 Turbo DOHC Engine ID "CAEB"

Check engine flashing misfire cylinder 2 and 3

i have a problem with a low compression on cylinder 2 and 3 (50PSI) i took the head apart I sent it to a machine shop got the head machine put the head back and still 50Psi

so i took out the complete Motor and sent it to a machine shop and Installed brand new head,valves and piston rings and still same. (I clean the s*** out of the intake manifold as well its like brand new)

I'm just running out of options the only thing i can think off is timing chain got a little bigger/loser

any ideas?

new oem spark plugs 4 new coil packs and Brand new Engine wire harness (different shop tried to change the spark plugs they broke all the engine wire harness connector while they were changing the spark plugs, had a short before now there is no short)

 

Did you replace the coil packs for those two cylinders? You said "rings" in the original post. Did they rebuild the bottom end (piston rings)?

 

Yes new piston rings new oem plugs 4 new coil packs and Brand new Engine wire harness (different shop tried to change the spark plugs they broke all the engine wire harness connector while they were changing the spark plugs, had a short before now there is no short)

This car is killing me, I'm just running out of options the only thing i can think off is timing chain got a little bigger/loser

 

Man, it sounds like a bunch of frikkin butchers were working on the car. I'd check the timing though. But even if it's off a tooth or two in either direction, you still should at least have decent compression. Was any damage or anything that may indicate a cause of the issue found on the original head? If there were no problems found (cracks, loose guides, bent valves, etc), I would have put all new seals in the old head and reused it.

Are YOU working on this car or are you depending on the mechanics to tell you what's going on? Low compression can come from 4 things. Dead piston rings, burnt or bent valves, leaking head gasket, or slightly off timing (anything more than slight is going to bend valves). Being that you've had a new head with new parts installed, new rings, surely a new head gasket, (and all this stuff is probably run a few thousand dollars so far) and you're still having this issue? Doesn't this engine use a rubber timing belt and not a timing chain? I've not seen a chain driven Audi engine in while. If someone got the timing off during the reassembly, it very well could have bent some of the new valves.

Bottom line is this, unless you're able to do the work yourself, find a shop that knows there stuff. I'm not getting an indication of competence from the ones you've dealt with before.

 

I have the same engine and same problem besides cyl 1 and 2. Did you ever find out the cause of the problem? I ended up pulling the cams back out again and did a leak down test and got only 10% leakage. Im at a loss right now with this car as to why i have only two cylinders with low compression

 

I know this was an older thread but wanted to follow up with what the issue was for anyone else having the same problem. Audi and vw use hollow camshafts with press fit lobes on certain models and when it bent the valves the force from the piston hitting the valve rotated or twisted the lobes on the camshaft. You can spot it because the two lobes for each cylinder are offset from each other.