Does a snapped timing belt on a Diesel engine cause expensive damage?

Question

I know it ruins a petrol engine, but heard it isn't half as bad on a diesel??????

Thanks in advance!!

F.

Answer 1

Most Diesels are interference fit engines so I'm not sure where you heard it's not half as bad.

Any engine that is an interference fit engine will have the piston smacking into the valves if the timing belt breaks. So it would only be alright for the timing belt to break in a diesel for the same reason it would be alright for one in a gasoline engine. If the engine is non-interference fit, you're safe(r), if it's an interference fit engine, your screwed either way.


As Diesels depend on high compression for ignition, most compress to the point where the valves have an interference fit.

Answer 2

It depends on the design of engine. Interference engines means the top of the piston can strike an open valves if they fall out of time. Free-wheeling engines don't take this risk. I don't know which is more common in diesel engines but I've never heard of this happening even though diesels have a very long engine life so you are probably OK

Answer 3

Yeah, a timing belt has essentially the same purpose in diesel as in petrol engines. A broken cam belt can really hurt your valves, it could bend them and that is EXPENSIVE. In a worst case scenario you could have to replace your engine. Modern belts last the lifetime of an engine, but older ones when damaged need to be replaced, by proper ones, not cheap rubber ones (rubber melts at high temps).

Answer 4

It is probably just as bad. If pistons strike open valves, you are in deep do-do.