movivion

Any help would be great... Thanks

Prospeeder

Big air leak after MAF sensor. PCV valve, broken breather parts under the intake, torn up maf to turbo boot, torn boost hoses, broken fittings, check valves, suction pump for brake booster ect.

Ranson

I have the same issue. I assume your post meant above 1000rpm. Long story short: I put a used replacement engine in my 98 A4 1.8T AEB due to previous owner running with no oil. The engine swap went well but the replacement engine has a rough idle. It smooths out when accelerating or revving the engine. It throws random misfires codes (only during idle) indicating air is getting in where it shouldn't. I have been unable to locate the air leak. Smoke tested the vacuum lines and pressure tested the intake. I also replace the intake manifold gasket. Two separate Audi mechanics were well paid to tell me they couldn't find any air leaks. I'm convinced the idle problem came with the replacement engine as one mechanic believes. I plan to remove the head from both the original and replacement engines and have the better of the two reworked professionally. Hopefully, this will resolve my idle problem. If anyone knows anything about this mystery or how it could possibly be internal to the head, I would like to hear it. If I can get it resolved, I believe this will be one nice A4 since most everything under the hood has already been replaced.