Hi all...I am after some basic info. How does a TDI 1.9 Octy work with a cold engine? I know this sounds silly, however, my car appears fine with a very cold engine but, when it warms up to normal temp, I have dire problems with turbo jutter, limp mode and a funny turbo squark when backing off the throttle. These problems are only sorted (sometimes) with recycling the ignition. Being a diesel, I pressume there isn't a choke, so why does my engine run great cold? Also, is there a sensor which does not allow the turbo to fully work until engine is at normal temp because this could be another reason why my car is fine when cold? My Hanyes manual is quite confusing to my non mechanical head. I have tested (off the car) the N75 valve and EGR solenoid and the valves appear to work (well, they click when 12v is connected to them). My MAF has also been changed and I have checked all pipes. I did manage to get under the car and feel for the turbo and the lever to it was very stiff to move the valve (!?) and could only move a few mm. Is this right? Car has only done 85k.

Thanks for any info on this folks.

Hi all...I am after some basic info. How does a TDI 1.9 Octy work with a cold engine? I know this sounds silly, however, my car appears fine with a very cold engine but, when it warms up to normal temp, I have dire problems with turbo judder, limp mode and a funny turbo squark when backing off the throttle. These problems are only sorted (sometimes) with recycling the ignition. Being a diesel, I presume there isn't a choke, so why does my engine run great cold? Also, is there a sensor which does not allow the turbo to fully work until engine is at normal temp because this could be another reason why my car is fine when cold? My Haynes manual is quite confusing to my non mechanical head. I have tested (off the car) the N75 valve and EGR solenoid and the valves appear to work (well, they click when 12v is connected to them). My MAF has also been changed and I have checked all pipes. I did manage to get under the car and feel for the turbo and the lever to it was very stiff to move the valve (!?) and could only move a few mm. Is this right? Car has only done 85k.

Thanks for any info on this folks.

I suggest the following as the first places to check

Temperature related problems - replace coolant temperature sensor. Simple job - use latest green version and make sure you but a new O-ring too. Do a search on here.

Small and stiff movement of turbo vanes actuator coupled with limp mode is almost certainly a clogged up turbo vane mechanism - many post on here about solving this.

Squeal when backing off the throttle is the auxiliaries drive belt slipping, probably due to failed freewheel on the alternator pulley - again many (and recent) posts on this issue.

Hope this points you in the right direction.

Mike

As above. Coolant Temp Sensor, & sticky vanes on the turbo.