fix to high RPMs on idle?

Hi, hope someone may help. I noticed that as of a year or so my 2007 MKV 1.9L TDI runs on idle at 950 RPMs (when it used to run at 800-850). This is regardless if the engine is warm (I do a 1 hour daily commute each way and engine always settle at 950 RPMs on idle) or right after a cold start.

Noting random here, fan not running on its own after I turn off the car; as long as the engine is on and the car is idling, the RPMs stay at 950.

I just checked the EGR valve at it's fairly clean (I had it disassembled and thoroughly cleaned along with the injectors 3 years ago). I also cleaned the air intake sensor with a special electric-contact cleaner to no effect.

Happy to provide further details.

Thanks for your input!

Anyone? Thanks...

VCDS readings

OK, so I plugged a VCDS cable and this is what I got. My takeaways: the timing belt seems off by a bit (meas. group 4) and the compression seems to be low (meas. group 11). Also, there was a fault code error related to a glow plug (judging from the mileage, must have happened one to two months ago). Would appreciate your input.

I've experienced fast idle when either the battery is low, or alternator got wet. The ecu ups the idle to increase the voltage and current. You can often reproduce this on a healthy car, by turning on all accessories, defrosters, heaters, etc and after a minute or so the idle will increase to compensate.

SootHappens said:

I've experienced fast idle when either the battery is low, or alternator got wet.

Click to expand...

Thanks... must be something else (me thinks). Coincidentally I replaced the battery two weeks ago but as far as RPMs on idle, they behave the same.