any idea y my mondeo si is knocking??

[nai]

my si has started knocking outta the blue. its a top end knock and only seems 2 do this between 2500 and 3000 revs she also knocks quitely on idle. we've changed her oil and filter as it was dead but its still there although a little quieter now.
Anyone got any ideas?
Does she have hydaulic lifters shes on a L plate? could this b the prob?

[EDLT]

I think it does have hydraulic lifters, although they usually tap at all revs. Are you sure its not a misfire?

[nai]

definately not a misfire and yes i have found out that she is def hydraulic lifters. she gets worse as she gets hotter took rocker off and there doesn't seem to be a prob with the cams. just dunno!

[Trooper2]

Just a thought, grab a long handled screw driver and use it as a stethoscope, have a listen around and you may pinpoint it. It could be something as simple as a water pump bearing going.

[nai]

tried it. seems 2 be coming from last 2 cylinders gear box end but not gear box???

[Zad]

Early Mondeo engines were *very* sensitive to oil type and change intervals. Using something like Wynn's hydraulic tappet noise fluid in your oil may help.

[dern]

Trooper2 said:

Just a thought, grab a long handled screw driver and use it as a stethoscope, have a listen around and you may pinpoint it. It could be something as simple as a water pump bearing going.

...or the alternator. How's made a slight knocking noise before it went and it was so bad when it did go that the AA man recovering the wife thought it sounded like the big ends had gone until he spent a good while pinpointing the source to the alternator which had shattered its bearings. Running the engine without the aux belt will discount the alt, pas and aircon. Disconnecting the water pump belt (for a very brief perdiod) will discount that.