1.2L coolant pushed to expansion tank. Head sealing issue

[scoobydo123]

Cylinder 4 failed leakdown test all other cylinders ok. Water level rises during test above filler neck of radiator. Have torn it down and have noted the following.

ARP's on affected cylinder measured different in both length and thickness compare to the other cylinders. Haven't measured them all but certainly the ones on number 4 do not measure the same. Previous owner had loads of head sealing issues as had MLS gasket with poor block preparation. I changed to Felpro composite gasket but reused ARP studs which are only 10mm. Has been ok for around 1000 miles. I have ordered new ARP's

I have slight rocking of the exhaust cam in the journal around cylinder 4 but it is not binding. This may have been already there. Have swapped cams and the rocking stays with the journal.

After taking the head off I hit it with a flat block and some 120 grit to clean up the gasket face and through the middle of the head there appears to be low spots. I continued until I could just see sanding marks on these low spots.

There is some corrosion around the waterways especially the additional one for cylinder 4.

Video and pictures below.


https://drive.google.com/file/d/1lKsEZfWrWdmhP2Nmw...

https://drive.google.com/file/d/1e-_jIIoANsvWzzft3...

https://drive.google.com/file/d/1CUEwRqEcVkBb3l8Ba...

https://drive.google.com/file/d/1IlJCXSMk6eHb9YI0d...

https://drive.google.com/file/d/1ZC_nLu5eG5DFMBspB...

Edited by scoobydo123 on Monday 1st September 08:46

Edited by scoobydo123 on Monday 1st September 08:47

Edited by scoobydo123 on Monday 1st September 08:47

[GreenV8S]

scoobydo123 said:

I hit it with a flat block and some 120 grit

If the surface is warped, machining is the way to correct that. Grit paper is often used as part of the cleaning process, rather than as a way to correct a warped surface. It's more likely to introduce warping rather than cure it. If you are determined to do it, I'd have thought checking the flatness with a straight edge and feelers would be better than watching witness marks.

[scoobydo123]

Yes agree. Unfortunately I dont have an engineering straight edge. I needed to clean all the old gasket off the head prior to getting it checked so that was my down and dirty hone mechanic attempt. Hopefully get it checked today. Might have to bite the bullet and get the block decked but hopefully head is flat still and was just the reused ARP's. Can we gain any insight with the videos I linked to.

[scoobydo123]

Measured the head studs ARP's they have an uneven stretch

10 bolts total
Inlet Ex
1 117.34 117.38
2 117.34 117.36
3 117.64 117.48
4 117.36 117.48
5 117.24 117.49

So 5th set(cylinder 4 ) that failed the leakdown had the widest delta. Either way new bolts are orfered