# Piston hits valve plate



## rmt2202 (11 mo ago)

There are piston marks on the bottom of the valve plate. Noticed it when replacing bad gasket. What's causing this? All I can figure is the bearing that holds the piston to the crank is worn and allowing extra vertical travel


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## iowagold (Jan 22, 2020)

yea could be connecting rod.

use a reverse dial and rock the crank for the run out...
or do a full tear down.


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## stevon (Mar 5, 2019)

rmt2202,

Have rebuilt engines and there could be several different issues, a bent crank, wristpin looseness in the piston or the rod bearing/hole. It's just speculation until you start tearing down the parts and start examining and measuring. It's a compressor though and not mission critical. If there is little noise and little end play in the piston travel then the head gasket thickness could be your problem.

Stephen



iowagold said:


> yea could be connecting rod.
> 
> use a reverse dial and rock the crank for the run out...
> or do a full tear down.





rmt2202 said:


> There are piston marks on the bottom of the valve plate. Noticed it when replacing bad gasket. What's causing this? All I can figure is the bearing that holds the piston to the crank is worn and allowing extra vertical travel


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