2003 A4 1.8

Codes P0300, P1250, P1297
Very rough idle, especially from a cold start. CEL on solid. No lack of power. Smooths out around 2000 RPM.

Dealer thinks it might be something in the EVAP system and wants to replace a bunch of hoses, etc. for $2000 without a gaurantee it will fix the problem (hose from oil separator to hose at 3 way check valve). They smoke tested it and got a couple minor leaks.

It has a small oil leak at the cam tensioner seal which I haven't fixed yet.

I'm wondering if the dealer is on to something or clueless and it is something less benign such as coil packs (originals).

Any help appreciated.

 

it doesnt matter if its a cold start or no for a blown coilpack.

All the symptoms are VERRRY similiar to a vacuum leak.
Most likely on of the check valves cracked. Thats why you dont see any loss in power after 2.5k rpms, cuase thats when your turbo starts spooling.

There is a DIY on a4mods.com how to find a boost/vacuum leak. or take it to another independent euro mechanic. Whatever it is, they gonna charge you less anyways. good Luck.

 

update: Their must be a huge leak (even though I can't find it). If I pull the PRV (hockey puck looking valve near firewall) and plug the hose running to the engine with my finger, the idle smooths out nicely. I'm planning to replace the PCV and check associated hoses. Any other ideas? Got the parts to check for the boost leak, but the transformer on my compressor blew so waiting for a new one...

 

Do NOT pay $2k for that. It's a vacuum leak. Search out the tennis ball method for finding vacuum leaks. Before doing that, though, examine all your thin flexible hoses for cracks (they are about 1/2" and have a fabric braid on the outside). You should also examine all of your plastic check valves to see if they're broken.