rough running & smoke at 2k-3k RPM unloaded only

[Mike Morriss]

I have noticed my 99 Beetle TDI runs rough and smokes (blue-white) if I run the RPM up to about 2000 to 3000 RPM unloaded (running with tranny in neutral). I can't feel a problem when driving in any gear. Any ideas?

 

[GotDiesel?]

Re: rough running & smoke at 2k-3k RPM unloaded on

Is your injection pump noisy? Mine did something like that although it got so bad I could feel it in gear too.

 

[IndigoBlueWagon]

I learned at the Fest that that it's not a good idea to rev the engine w/o a load. The ECU will try to figure out what's going on and retart the timing, I think.

If the car runs fine under load don't worry about it. At least I wouldn't.

 

[moondawg]

This sounds like a timing issue. Is the timing very retarded?

Do you currently have any CEL's? If your temperature sensor is bad, the ECU cannot properly adjust the timing.

moondawg

 

[Mike Morriss]

Warmed the engine up and tried it again and found it was smooth at all RPMs and no smoke. I used to run the engine up after an oil change to get the oil pressure up to check for leaks before buttoning things up. I'll just have to remember to get the engine warmed up good before doing this to check for smooth running in the future. Thanks for all the suggestions!

Mike