A4 b5 tdi non starter

[neil w]

Help please, I have a 1996 A4 TDI 110 (afn motor), 185,000 on the clock and up until last week running superbly. Anyway last week on the way home from work the serpentine belt snapped whilst travelling at 70 mph. drove on for 1/2 mile to get the car to a layby on the A1 and as I pulled in there was a bang and steam from under the bonnet.

To cut a long story short the serpentine had taken out the aircon belt and wiring and at the same time the heat had for some reason blown apart the plastic elbow on the back of the head (which contains the temp sender ) the plastic elbow appears to have gone very brittle.

Car was recovered and I got a new elbow, seal and genuine water temp sender and pulled the front panel off the car, the radiator was a bit manky along the bottom edge so it along with the other parts were replaced and a new thermostat put in.

Put it all back together with new belts and anti freeze (minus the front bumper) and it started straight away and ran fine up to temp and the fan cut in. Took it for a short run of 4 miles and it performed perfectly.

The next morning i put on the bumper and went to take it for a proper run, 50 yards up the road the car stalled and struggled to restart pouring out vast amounts of grey/black smoke and I limped it home, since then it will not restart.

The head gasket is fine, no water in the oil, no oil in the water etc , I cracked off the injectors and there is fuel ( I changed the filter anyway) but no starting.

All the wiring appears fine and there are no fault codes recorded. I've changed the master injector just incase (I have a known good spare) , the cambelt looks okay and it turns over fine but no starting.


I sprayed in easy start and it fires straight away but only until it is burnt off and then nothing.

Any ideas would by grateful

[micheal balbrig]

Help please, I have a 1996 A4 TDI 110 (afn motor), 185,000 on the clock and up until last week running superbly. Anyway last week on the way home from work the serpentine belt snapped whilst travelling at 70 mph. drove on for 1/2 mile to get the car to a layby on the A1 and as I pulled in there was a bang and steam from under the bonnet.

To cut a long story short the serpentine had taken out the aircon belt and wiring and at the same time the heat had for some reason blown apart the plastic elbow on the back of the head (which contains the temp sender ) the plastic elbow appears to have gone very brittle.

Car was recovered and I got a new elbow, seal and genuine water temp sender and pulled the front panel off the car, the radiator was a bit manky along the bottom edge so it along with the other parts were replaced and a new thermostat put in.

Put it all back together with new belts and anti freeze (minus the front bumper) and it started straight away and ran fine up to temp and the fan cut in. Took it for a short run of 4 miles and it performed perfectly.

The next morning i put on the bumper and went to take it for a proper run, 50 yards up the road the car stalled and struggled to restart pouring out vast amounts of grey/black smoke and I limped it home, since then it will not restart.

The head gasket is fine, no water in the oil, no oil in the water etc , I cracked off the injectors and there is fuel ( I changed the filter anyway) but no starting.

All the wiring appears fine and there are no fault codes recorded. I've changed the master injector just incase (I have a known good spare) , the cambelt looks okay and it turns over fine but no starting.


I sprayed in easy start and it fires straight away but only until it is burnt off and then nothing.

Any ideas would by grateful

I would say you could check the valve/pump timing and also check the possibility of what ever keyway is in the crankshaft for driving the belt pulley
being damaged when belts locked up.
Regards
Michael.

[adamss24]

Yeah, it sounds like timing slipped a tooth or two ! Get it re-timed and it should start right away...

[neil w]

Panic over, pulled off the front end and all the covers today and found a piece of serpentine belt approx 3mm wide and 5 cms long around the bottom pully, it had caused the belt to jump one tooth knocking out the cam and pump timing.

Re timed the engine and pump and as a matter of course stuck on a new belt and tensioner (the last one had done 35,000 miles , started first turn of the key and seems to have caused no damage to the engine, if anything it is sounding a bit sweeter than it was before