Has anyone seen marks like this before? The history of the engine is unknown to me - and the car isn't on the road yet so it's not a failure that's occured during my ownership. Any thoughts on this would be much appreciated.
Evening all, my engine was low on compression on cylinder no 2 - circa 80psi compared to 150 on the other 3. After taking the head off there's no
obvious signs of damage to the head or gasket but I have noticed these marks on the cylinder wall of the offending cylinder:
Has anyone seen marks like this before? The history of the engine is unknown to me - and the car isn't on the road yet so it's not a failure
that's occured during my ownership. Any thoughts on this would be much appreciated.
Only a guess but i would say. Engine has been left for a number of years and piston ring have corroded, that is why you can see ring marks. Possibley water in the cylinder or plugs left out.
quote:
Originally posted by madteg
Only a guess but i would say. Engine has been left for a number of years and piston ring have corroded, that is why you can see ring marks. Possibley water in the cylinder or plugs left out.
If you cannot feel any ridges then rough the bore with some wet and dry following the honing marks on all cylinders then fit a new set of rings.
As above Its been standing or possibly started up and then turned off without getting up to full working temperature
Try and see if you can catch the marks with your nail or not, Hopefully it will be the latter...
quote:
Originally posted by perksy
As above Its been standing or possibly started up and then turned off without getting up to full working temperature
Try and see if you can catch the marks with your nail or not, Hopefully it will be the latter...
It is probably a stuck ring the pitting is due to moisture ingress via the inlet or exhaust.
But a drop to 80psi from 150 is huge for a piston ring problem alone. I would also check the valves
It would have been nice to do both dry & wet cylinde leak-down tests before stipping as this can usually give better clues as to what to look
for.
quote:
Originally posted by britishtrident
It is probably a stuck ring the pitting is due to moisture ingress via the inlet or exhaust.
But a drop to 80psi from 150 is huge for a piston ring problem alone. I would also check the valves
It would have been nice to do both dry & wet cylinde leak-down tests before stipping as this can usually give better clues as to what to look for.
quote:
Originally posted by Daf
quote:
Originally posted by perksy
As above Its been standing or possibly started up and then turned off without getting up to full working temperature
Try and see if you can catch the marks with your nail or not, Hopefully it will be the latter...
Nope can't feel them which is good news, is it worth me re-honing the bore?
Any recommendations an piston rings for the zetec blacktop engine?
as the orignal cross hatch hone pattern
is still clearly visible. quote:
Originally posted by Daf
quote:
Originally posted by britishtrident
It is probably a stuck ring the pitting is due to moisture ingress via the inlet or exhaust.
But a drop to 80psi from 150 is huge for a piston ring problem alone. I would also check the valves
It would have been nice to do both dry & wet cylinde leak-down tests before stipping as this can usually give better clues as to what to look for.
To be honest when I saw 80PSI I was expecting to find an obvious issue when I took the head off - however other than those marks on the bore there's nothing sinister looking at all.