Genteleman: while i was driving the timing belt broke after replacing it
the motor turned but did not start, friends say the valves my ae be
damaged this consists of replacing the top `end could thier be more
On Mon, 23 May 2011 11:30:40 -0700, Billy Gonzales wrote:
Without doubt there will be some bent valves. That might be the limit of
the damage; piston damage is possible, but less likely.
Best bet is to remove the head and look. If everything except the valves
is OK, getting the head reconditioned at an engine rebuilder is the best
If you are looking at getting the whole job done at a garage, it may not
be cost effective to do on an 11-year old car.
Whether or not there is valve damage depends upon
whether your engine is an interference or non-interference
type. Your dealer will be able to tell you.
In an interference engine the timing chain keeps the pistons
and the valves apart. If the chain breaks you've got a serious
In a non-interfering engine (usually with a timing belt instead
of a chain), the pistons and valves do not occupy the same space.
The belt simply keeps pistons and valves in sync. A belt failure
will stop the engine but will not cause additional damage.
On Mon, 23 May 2011 21:06:31 -0400, Don McC wrote:
There are very few OHC engines of the last 20 years that are not
AFAIK, the last Ford one was the Pinto from the 1970's.
It makes no difference whether the camshaft(s) is driven by belt, chain,
or gears. What makes an engine one that will self-destruct if the crank
turns and the cams don't is the combination of valve lift and piston-to-
On Tue, 24 May 2011 18:32:49 -0400, Don McC wrote:
I made the assumption that the OP was in Europe, where all Focus petrol
engines are interference. If in the USA, it does indeed vary by engine
type. Even the model year won't help, as different states used different
engines according to their environmental legislation.
On Mon, 23 May 2011 11:30:40 -0700, firstname.lastname@example.org (Billy
I assume you replaced the belt yourself. Are you absolutely certain
you got the timing marks lined up properly when you put the new belt
Have you considered doing a compressing test on the cylinders?
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