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-   -   Dented Piston (http://www.focusfanatics.com/forum/showthread.php?t=302290)

mysonsfocus 11-14-2012 07:50 PM

Dented Piston
 
Just got the head off and guess what, ate the #4 intake valve seat which has dented the piston in #1 and #4 cylinder. The cylinder walls are undamaged, DO I HAVE TO REPLACE THE PISTONS???

DerbyDave 11-14-2012 08:22 PM

as long as the damage is limited to just a dent and the piston dosen't have a hole in it then you shouldn't have to replace it.

mysonsfocus 11-14-2012 08:27 PM

Maybe I understated the amount of denting...the valve seat bounced around and made the top look like a rocky river bottom...It is not leaking oil by the rings, but it looks pretty dented over entire top

amc49 11-14-2012 09:18 PM

Can you provide a pic? Usually that much means you gotta change it, absolutely if any denting is within 1/4 inch of piston edge. There the denting fractures through to let ring land come loose as soon as engine runs, you'd be repairing it for nothing. Cast pistons pretty much crack under dents unless the dent is very shallow because they are brittle. Multiple dents close to each other are always cracked underneath the dents.

mysonsfocus 11-14-2012 09:22 PM

Thanks, the denting is right up to the edge all the way around, sounds like a set of pistons is on the order list. Any thoughts on removing the engine and leaving the auto trans in???


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