[Vwdiesel] Piston selection--- (when reboring or re-ringing)

slatersfb at aol.com slatersfb at aol.com
Tue Apr 12 12:58:25 EDT 2005

Checking piston fit with feeler gauge might take a lifetime to learn. Piston & bore are round, while gauge is flat. Also the thicker the gauge, the less it flexes to conform to gap between piston & cylinder wall. Bore gauge is the way to go & large mic for pistone.
Truth be told, pistons in my Jetta are so loose they slap under load & have for the last 50k miles. No oil use though. Never had any problems caused by loose piston fit in any engine. A little noisey maybe is all.
Loren pointed out to me that  my way of checking piston fit was near impossible 
to do.
Simple really --- I did not explain it right.

I learned this procedure from a mechanic at Finning Tractor  Van.BC.

Clean bore  --clean Piston NO RINGS or pin.  Long feeler gauge blades  about 12 
" american inches.

With a 5 thou blade in cylinder and piston slides right through --on its own 
weight ?    NO
good for a diesel VW.  You need a bigger piston------  well you DIY's gets the 
drift ?---if NOT ?.
Leave it ALL to a good shop.  ----BUT make sure you tell them to fit on the 
THIGHT side of specks.

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