Good evening all, a little teaser here.

What does the collective see as a possible cause of the marks shown, and should it be rebored?

Just stripped down the motor and when cleaning the bores, found this mark on cylinders 1 & 2 on the right hand side when viewed from the front of the engine.

It seems to sit just where the top ring stopes. It is a depression and can be felt with the finger nail.

Pistons all look good and no ring problems. (except all oil rings were gummed up.)


Cylinder bore mark

Len.

Mmmm difficult to tell TBH but it looks like poss earlier HG failure has let water into the bore. The cyl would then corrode but the oxides would be burnt off during combustion thus leaving the worn indentation. Given that an engine usually stops in or around the same 2 positions I 'd expect to se a mark at the bottom of the stroke as well although it will look different.

just a guess mind. As for needing a rebore well you'd need to measure it up and see.

Either way the general consensus it's a no brainer contemplating a re-bore on a Zetec or is this a load of tosh?

The wear shown, Bore ridge is typical of a 50,000km motor.
A much bigger problem.. if ..this is a recently (inadequately?) rebuilt engine.
The rust does suggest a Headgasket leak, if not outright failure

First off I would try a light hone, then measure to see if the bores are in tolerance and a new set of rings, cheaper than a rebore and pistons.

Anything you can feel worries me.
For the low cost of another engine I would go that route.

Thanks for the replies.

Replacement engine is a problem as I need a pre 95 unit for IVA emissions and I have just bought this one.....
(getting rare and expensive)

and I doubt I can get my money back.

The present wear on the rest of the cylinder is good - I have cleaned the top area with scotchbright and that has
shown the ring wear mark. Checked the rings in the bore and the gap was within tolerence, so bore / ring wear is not bad

There was no sign of head gasket damage but the head has been of previously, so maybe that was when the damage occured.

I will be getting the head skimmed so I will ask about a honing then. I may just rebuild it as is and get it on the road.
After that I can replace it with any unit if required... May be cheaper in the long run.

Len