Problems after snapped cambelt

[xcatch22x]

Hello,

The story so far is that the 1.1 S plate Saxo I have been given has a suspected snapped cambelt.

After inspection this has been confirmed.

Now, after turning over the engine there does not seem to be any metal to metal contact. So the new timing belt has been fitted and the engine turned over again. Still no contact between anything.

I rechecked the timing belt by inserting the 6mm pin through the engine block into the flywheel and a 10mm bolt through the camshaft sprocket into the head. Everything here seems fine.

With the rocker cover off the valves when cranking seem to be returning correctly and there would appear to be some compression.

When trying to start the car we are getting it backfireing through the throttle body/carb (single point inj?) and it wont start. The fuel is there and so is the spark.

So, just how much damage can have been caused to the engine when the belt snapped? Are we talking just a couple of bent valves? Holes in pistons?

It seems strange that it wont fire on at least a couple of cylinders.

Any thoughts before I get the compression test done?

[ScottyD-VTS]

did u strip the head down 2 c if there was any bent valves or did you just put a new timing belt on? I would personally strip the head and check the valves if they are ok then maybe the key on the cam sprocket has snapped allowing the sprocket to turn freely from the shaft

[xcatch22x]

You have got me thinking now. I think the next check will be to see if both valves are closed for No1 cylinder when the timing marks are aligned. This would tell me if the cam sprocket has indeed moved.

We have not yet had the head off as we are trying to avoid it if possible. The compression test may be the best bet first.

Are the valves expensive to replace? I will do all the work myself so no labour costs involved.

[Joesnow]

backfireing through the throttle body/carb

Bent valves...

So, just how much damage can have been caused to the engine when the belt snapped? Are we talking just a couple of bent valves? Holes in pistons?

The pistons should be fine just a few bent valves...

It seems strange that it wont fire on at least a couple of cylinders.


If the timings correct and it still won't start there must be a few bent! A compression test could give you a clue which ones are bent...