Snapped Cam-belt Question
 

Here is a question for someone with previous experience of this sort of thing.

My Cam-belt snapped on my D5 just as I was starting to pull away from a roundabout .
Now, given that it happened at low speed ,what are the chances of there being no damage to the valves or pistons?

Should I put a new timing belt kit on and see if I can turn the engine manually
or not ?(At the cost of around £150). Or would I be as well to take the head off first to see what damage there is ? (Because if there is piston damage, the car is basically scrap).

Thanks in advance for any answers .

Buy a belt at £20(ish) and put it on, its a fairly simple job, no need to build it back up completely before trying to start. When the marks are all in place and the belt is on and tensioned, give 2 turns by hand, if all seems ok, turn the key. I'd be surprised if there is piston damage, probably will be valve damage though. You should be able to pick up a 2nd hand head or engine at sensible money. If it starts with no issues, go buy a new tensioner and replace it and you have a shiney new D5 engine again :)

Thanks for your reply bud.

I haven't had a chance to look at it yet, since it only happened on Fri night,and I had to try and find another runabout over the weekend to use for getting to work.
If the tensioner is ok ,then I will certainly try your plan. But am I right in saying that it is common for the tensioner to fail,and this causes the belt to come off or snap?

I've heard of belts snapping, but not heard of the cause. There's kits on eBay for £65ish, be worth pulling the cover off and see whats needed, get the bare essentials to get the engine running them make a decision from there. Bound to be someone here would have replaced a belt recently and even give you their old one for the cost of postage.

As said its got to be worth a go with a new belt, but I would very suprised if the engine survived scot free. What did you do when the engine stopped? Did you know immediately that the belt had snapped ? Or did you try and turn the engine over thinking the engine had stalled? If you turned it over after the belt snapped then i'm afraid damage to the valves,pistons and ,in extreme cases , the camshaft is likely.

I never thought of that Mark.
Yes, I did try to restart the engine after stalling .
So the starter will have turned the pistons and they will have been colliding with the valves ? Is that how it works ?

yes afraid so .
mike

Attachment 65454 The offending knackered tensioner. (I put the belt back on for the sake of illustration)

Attachment 65455 The results;

Attachment 65456

You've hit the nail on the head,no pun intended !! If you spun it over then its almost certain that a piston would have collided with (at least) a couple of valves at best. Sorry to be the bearer of bad news.

What year, how many miles on car and belt ?