My zetec seems to have a rattle at 3000 rpm ish on very light throttle. no rattles under load or off the throttle or at any other rpm!!
The tappets rattle on first startup if its left for couple of weeks which must be oil drain back through filter but this rattle seems to have started from nowhere.
Engine has done about 42k miles and was mint inside when i checked it.
Any ideas?!???

 

Is it the 1.6 fiesta zetec s or 1.4? I know these had issues with the bottom ends failing from low miles if not serviced well. Normally accompanied with loss of oil and smoke.

May be worth getting it looked at to see if it the bottom end letting go.

The upside is you can get another lump pretty cheaply and throw it in. Just make sure you see the replacement lump running and dont just trust the seller or rely on 30 day warranties, not much good if you have to rip it back out and send it back etc.

 

Its 2.0l silvertop. just driven it again. drives ok but defo rattling. Worse when engine gets hot. looks like it could be engine strip job

 

I fitted a boost controller and i thought i had knaked my cams because the noise of the solenoid mounted on the bulkhead sounded exactly like rattling cams (i mounted it on a rubber bobbin for a mini exhaust- noise went away)

moral - check its not something stupid like a rattling heatshield 1st

 

Check your exhaust dude my s1 mate a rattling noise around a certain rpm and it was the down pipe only turned the nut a 1/4 turn and it stopped

 

it sounds like big ends but the engine was like new so i cant see how it would have gone wrong, unless its due to lack of use or contaminated oil? the car has only done 500 miles in 2 years!
Here is a video of it. you can just make it out when i hold the revs still
https://www.youtube.com/watch?v=uOPW87d9TRQ&feature=youtube_gdata_player