Arfa Daily wrote:
Focus 1.8 Ghia Estate. 2000. Tad over 100k miles. Last night, it suddenly
started making a nasty noise from the engine, so bad that even my daughter
commented on it, and it's got to be noticeable for her to hear anything
wrong with a car engine ...

When it's idling, it sounds like a diesel. That's honestly the best way I
can describe it. As the revs build, it becomes more of a growl, until at 2k,
it smooths out like a switch has been thrown. I've had a listen this morning
with the bonnet up, and it sounds as though its coming from around the front
side of the engine, and doesn't sound as though it's anything to do with the
exahaust system. My tame mechanic friend, who hasn't actually heard it yet,
suggests a leaking injector seat can cause this sort of problem, allowing
excess fuel into a cylinder at low revs, causing random detonations. This
sounds a bit fanciful to me. Anyone got similar experiences to share ?
Anything common on this engine ?

Thing is, it sounds worryingly like my little Fester did, when it knocked an
end out, and which ultimately led to my scrapping the car, although that may
have been slightly different in that the worst of the noise was when you
were on a light throttle at any revs, whereas this definitely seems to go
away as you pass 2k revs.

Any thoughts from the (far better qualified than me) 'usual suspects', much
appreciated.

I am not a ford expert, but IIRC there's an issue with some ford engines
as fitted to Mondeos and Focuses where a valve or 2 will stick if you
don't use exactly the right spec of oil.

Cheaper than an injector seat, worth a try?

--
Douglas