Juddering A3 Help please!


Registered User
2005 A3 2.0 TDi Auto (BKD 109,000 miles)

Ok so my car has suddenly started to develop a very noticeable judder when cold at around 1,700rpm. It feels like fuel starvation, raising the rpm will instantly cure the problem - and it disappears completely when the engine is up to temp.

VCDS shows the only known problem the car has is a worn glow plug harness which occasionally throws an eml and makes the car slightly grumpy on cold winter mornings - but it always starts. The second problem is the coolant temp sensor on the radiator, that has a mind of its own. However the engine coolant sensor seems to overrule the faulty rad sensor and the car always displays the correct temp.

But the above issues are old and I just live with them, the engine harness is a nightmare to change and the engine temp sensor works fine. So what's causing this new juddering that literally rocks me back and forth!?

Thats for all your help and advice

ps. New fuel filter 12,000 miles ago, redex very occasionally used, never use supermarket diesel. Could it be the egr?!


Registered User
Spark plugs, pcv, maf


Registered User
Check the fuel filter again and check to see if the cannister has oil in it. If it has then thats your problem with the kangaroo'ing. The tandem fuel pump seals breaking up allows oil to seep into the fuel so get that checked out too.