O/T ... engine noise question?

I hope you'll forgive the O/T post as I appreciate this isn't a Honda
question. However I've often had good advice from here and it's really an
engine issue rather than anything car specific! And I still have an ATR as
the main car ;o)

I'm thinking of buying a UK spec Focus 2.0 Ghia (5 door, petrol, manual,
2001 reg). I took it for a test drive today. Starting engine from cold,
all sounded well enough and the car felt solid on the road. However there
was a strange engine noise below about 2500rpm that has me a little worried.
I can best describe it as like demented pinking (but not pinking)! It's
quite noticeable and happens in any gear, but obviously you hear it more in
3rd/4th as you can keep the revs there (needs some throttle to make it
happen - dies down at constant revs).

The car has been off the road for almost 6 months, so probably has yucky
deposits at the bottom of both the petrol and the oil. They're offering to
do a mini-service and MOT for free. The service would include changing the
oil and filter, flushing the oil out and the fuel system with a cleaning
solution. They say they'll remedy any faults (it will have to pass the MOT
anyway) and give a 3 month warranty on major problems.

Unfortunately I only got to speak to their sales guy and not one of their
mechanics and he didn't know what the noise was. Do any of you have any
idea at all what it might be? The car has some nice extras in it that you
don't often see and is in good condition otherwise so it would be a little
bit of a shame to let it go, but not the end of the world!




a

 

Sounds like pinging..Could be many reasons. Anything from low octane,
to
improper timing, to overheating. I'd probably pass on the car
myself.
But if you bought it, I would let them flush the fuel system, but
*not* the
oil system. 6 months is really not enough time to degrade fuel too
much,
and the oil is not going to be any problem. All they need to do is
change the
oil and filter.
They need to find out what the *real* problem is before I would even
consider
buying that car.
MK

 

I found this when browsing around and it sounds a lot like what I
experienced:

http://forums.focaljet.com/zetec-tuning/420335-low-rpm-2000-engine-noise.html


It's a strange one. I'd have thought improper timing would have been
constant across the rev range? Overheating wouldn't be the issue as it did
it right from cold until I came back with it hot. Why not flush the oil
system btw?






a

 

If you're serious about purchasing the car, then it would be worthwhile to
get a prepurchase inspection performed by an independent mechanic. If the
seller won't let you do this, then walk away from the deal. Even so, why
start out with a car with a problem unless the price is significantly lower
than other comparable cars?

Eric