Focus None Starter?

[anthony25]

My uncle has a 2003 1.8 focus zetec petrol 104k miles car cut out whilst driving,I've been have a look I've turned the key car seems to have no compression,it's as if the engines just spinning over, cam belt is intact,,cars been plugged in no fault codes,...Is it possible the belt has slipped and so on don't really want try bump it incase I cause damage,is it conceivable that the engine is damaged etc??

[tonyav]

Stands a very good chance that the cam belt has slipped a tooth or two.
If it has slipped a tooth or two it's unlikely to have done any damage ie to the valves or pistons.

[anthony25]

Yes the belt has not snapped tony do you think it would be worth buying a belt kit and timing it up and see what happens?

[malagabob]

Have you tried tugging the cam belt to see if it's snapped rather than a visual check. 104K should have had a new belt about 30K ago

[anthony25]

I've removed the cam belt cover turned the engine I've the belt does complete rotations the the belt is not broken my money's on for there to be no compression the belts jumped putting the timing out..could will be looking to see if I have a spark and fuel to getting through today

[bhg481]

I don't see why a slipped belt would cause loss of compression. The timing belt should set the engine to fire when the pistons are in the right position - a slipped belt will cause the spark to occur at the wrong time but it will not stop compression taking place. The cheap way to check for compression is to remove the plugs, put your thumb over one plug-hole and turn over the engine, Repeat for all cylinders.

[anthony25]

When I put my thumb over one plug hole what am I actually looking for?

[bhg481]

When you turn over the engine you will feel the pressure push your thumb off the plug-hole as that cylinder comes up to its firing position. All cylinders should feel the same. You can buy a gauge if you want an accurate reading but the thumb test is good enough to check that there is some compression there. The compression ratio of a petrol engine is about 8 to 1 which will generate ample pressure to blow past your thumb.

[anthony25]

Ok I shall try that tomorrow in the event the belt has slipped or the tensioner has failed is the a procedure to re time the engine?.. Will the engine have to be rotated by a few times etc as how will I know,if everything is tdc??

[bhg481]

There will be marks on the engine and pulley which indicate TDC - you need a Haynes manual to tell you where they are on that particular car. Engines are normally timed when running using a timing light. The timing can be a long way out and the engine will still run, albeit badly. I had a colleague who complained that his car had no power and he was right. I checked the timing and found that it was 10 deg retarded instead of 10 deg advanced.

[tonyav]

The silver top does have timing marks on the crank pulley which line up with the angled mark on the sump.

The black top doesn't have these marks but does have the threaded hole for the crank locking pin.