Thread: Timing belt destruction....

John,

No need to take the head off. The valves on the Tdi are vertical in the head and the pistons are flat top so the pistons just push the valves straight up onto their seats. The only damage is either or both, broken rocker arms or bent push rods.
Had the belt been tracking off the pulleys and worn on one side, was the cover full of black belt dust?

Alan

Hi John,

Generally the valves will be quite OK. As the valves work vertically in the 300Tdi, they hit the top of the pistons straight on and don't get bent. You'll probably have some pretty circular indentation on the piston crowns though... Usually the rockers and pushrods absorb all the impact damage.

I wouldn't remove the head yet. Repair the valve gear and belt (complete with new idler, tensioner and flanged crankpulley), get it running and if you still have full compression of all cylinders, leave the head alone.

Hope this helps.

Thanks for the info.

Alan do you sell the push rods and rocker arms. Had a look at the web site but couldn't find them. If so how much are they. I would need 8 pushrods and two rocker arms (one exhaust, one inlet) as well as the timing kit. It appears that the belt had been wearing against the cover as there is a nice groove cut into the cover plate especially around the crankshaft end.

Build date Jul 1997
Vin SALLJGMF7VA741707

Originally Posted by JohnM

...It appears that the belt had been wearing against the cover as there is a nice groove cut into the cover plate especially around the crankshaft end...

From that description, it sounds like the proper kit had not been fitted when the belt was replaced 2 years ago. Either that, or the groove in the cover was made before then. But it would explain why you got less than 50,000 before the belt failed.

I'll second what the others have said... The valves should be OK so don't bother taking the head off. If you've still got problems when it has all been re-assembled, then think about popping the head off.

As for the cause of failure, it sounds like the tension on the pulley was set too high, pushing the belt forwards into the cover. Just make sure you clean all the schrapnel out of the timing cover before re-assembly.

HTH

M

Also noted that the crankshaft gear is only flanged on the one side nearest the engine block. Is there a new designed crankshaft gear that is flanged on both sides? I would assume this would also help the belt not to run off and hit the timing cover....

In the repair kit STK4096, the idler pulleys were plain and the crank pulley has a flange on both sides. The kit we fitted also had pump bracket and rear timing cover.

Check the Difflock site for all the info, including tips. You'll need pins to hold engine in TDC position & pump in the correct position.

This repair also featured in AULRO Mag (early edition) after we wrote up the refit. Check the crank seal and O ring for patency - for the extra $20 I'd renew them.

Only 11 Nm tension is required on the belt - no more.

HTH

Pete

Woops, STC4096K. Seniors moment.

Pete