GOLF MK5 Problem with idle RPM

[Sabedin]

Hello... I am new to this forum... and I could need some help ...

I have a problem with my GOLF MK5 2.0 TDI,.... when i idle my motor it runs aprox. 40 seconds on ca. 850 RPM and then it jumps to 1000 +/-50 RPM.

I tried every thing... but still don't know what this could be

Please Help...

[Seatman]

The only thing I can think of is the coolant temp sensor, my car was doing a similar thing but it's not a PD, might be worth checking the temp reading with vagcom.

[Sabedin]

I will check that... but only thing funny is that it does the same thing not just when the car is warmed up but when cold too... i measured the time until it does that every time is 40 seconds of idle time... and when I drive aprox. 5 km it calms down and starts all over again when i stop for few seconds... and its really anoying :S

[Bambur]

Could it be so that something gives a load to the engine, so its ECU decides to increase the RPM?

Any faults in the engine ECU memory?

[Sabedin]

I've have to check that... this weekend my friend will check the whole car with the VAG sistem... Last time I've checked the system showed a error on the 4th cilinder.... but we erased it and it was gone... hope i've have no error on the ECU