hey all again, my octy has an intermittent problem. it's a 2007 1.9 tdi 105 pd engine and when she is idling when warm every now and then it will intermittently slightly jolt that can be felt in the bottom and back of the seat. she idles around 850 rpm and the needle does not move at all and there are no lights on the dash to indicate fault. also if I turn the lights on or the heated rear screen it suddenly stops the little jolts and idles smooth but soon as I turn it off it does it again. this is a very random problem. is it anything I should be concerned about or shall I just put up with it. 

work been done on her is as follows

timing belt changed at 90000. current mileage is 115000.

full service history and just had full service done last week. fuel filter oil and air changed

put some decent fuel cleaner in and it has helped her run smoother after a trip to coast. 

average mpg after a 100 mile drive was 58 mpg which I think for this engine is fantastic so can't see it being injector problem.

any info or advice appreciated

cheers.

 

Have you ever had the aux belt clutch pulley changed?

 

Mine behaved quite similar.

 

https://www.gsfcarparts.com/904vg0200

 

Add yourself to GSF mailing list, and you'll get emails every other week with 50 odd % off their marked prices.

 

I think I paid for 1/2 hour labour to get it swapped over when I had mine done.

 

 

Has the DMF been replaced?  

 

A bad flywheel can cause vibrations too. Since this is a known issue with the 1.9 it might be worth checking that as well.

hi djsmiley. I'm not sure if it has in the past. there is no chattering or anything at idle or any judder when pulling away. if i push clutch in or have clutch out it doesn't make any difference. 

can you see if it is seized the alternator pulley at all.