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Top of piston is shiny

4545 Views 3 Replies 3 Participants Last post by  GTJIM (R.I.P.)
Hi All,

I thought I'd just throw this out here to see if this is something I should be concerned with.

I was putting my cylinder head back onto the block this morning. And in the process of cleaning the top of the block, I noticed that pistons 1-3 look about the same on their tops. A layer of carbon had deposited there. But on piston #4, the top is shiny. I scraped off as much of the deposits from all the piston tops as I could. The first 3 pistons were dry, like dust. But the last piston was like oily dirt.

Since I had the head redone, I hope this will fix whatever caused #4 to be different. Anyways, I thought I'd just see what you all think.

Thanks and Happy New Year,


PS. What do you use to torque the last head bolt on the driver side closest to the firewall? It's a pain to get to.
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The oily deposits will have come from the antifreeze in the cooling water - if coolant had been getting into the cylinder.
Check the old head gasket - if you still have it - for signs of "blow-by" and leakage.
I am pretty sure that any Opel head rebuilder would have checked the casting for cracks before expending any effort on it so carefully check the cylinder block for cracks or leaks too.
Carefully check the head/block faces for flatness as well.
Use a top quality Felpro "Printo-seal" head gasket and make sure that none of the head bolts either bottom out in the threaed holes (if your head or block have been surfaced) or have "dozy" threads ( ie stripped threads )

1 - 1 of 4 Posts
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