K11 1996 Grating noise when cold

[robj_1992]

Just wondering if anyone could help.
I have a 1996 N reg Micra. After first starting, the engine makes a grating noise, like metal rubbing on metal. When the engine is warm, the noise disappears.
I have took off belts and worked out it isn't the water pump or idle pulley. It seems to be coming from the timing chain area. Any ideas?
Cheers
Robert

 

[frank]

a slack chain should quieten after a few secs robert (or else clatter continuously when totally knackered )

 

[robj_1992]

Thanks for the response, it doesn't sound like a chain rattle. It sounds more like a scraping/rubbing noise of metal on metal. It takes a good ten minutes until the engine is warm before the noise disappears.
Cheers again,
Robert

 

[MopedMan]

Do you have enough oil in you engine??
Because as far as I know, the tensioner for the chain is hydraulic, so no oil means the chain is slack.

 

[Harlen]

I get this sound aswell. It doesn't seem to make any change to performance, it's just a weird sound. Sort of a high pitch metallic wail. I get it mostly in low RPMs.

 

[robj_1992]

Yes I have plenty of oil in my engine. Only recently changed the oil and filter. The noise isn't the same as a slack chain. It is like metal rubbing on metal. It only seems to be apparent at low RPMs as the above person noticed, but I possibly can't hear it when it is revving higher due to engine noise.
We are going to take the panel of the side of the rocker cover (on the drivers side) to see if anything is noticeable.

 

[robj_1992]

Just taken the inspection panel off the side of the head and noticed the top chain was very slack (bottom was fine). It turned out the top tensioner was jammed so we removed and cleaned up. This tightened the chain a lot but didn't stop the noise. Dad reckons a cam guide may be blocked so no oil getting in?