I bought a B6 A4 1.6l

The car is fine on open roads, brilliant in fact, but when it hits traffic and the water temp hits 90deg the engine will start acting up. If the engine light comes on, there is poor performance from the engine and exhaust smoke is much greater.

This will remain until I travel up a motorway at a constant speed for about 20-30min and suddenly engine light goes off and runs perfectly again.

Before I had a bad thermstat, it is always opened, so the water temperature always at 60 to 70 degree, in that time, the car runs well. Now I changed the thermstat, then the water temperature can reach 90, then start smoking.


I saw a guy posted many years ago have the same pone whoroblem as me, anyone who knows what is the reason?