<VV> rebuild 140 engine noise (answer)

Michael Kovacs kovacsmj at sbcglobal.net
Sat May 20 18:45:02 EDT 2006


 I must thank all that responded to the problem, all good stuff but we were all wrong. 
   
   After pressurizing the #4, I immediately got air leaking back at me!! Think, Mike, what could it be. Ah ha! The #4 had a spark plug hole so booger-ed up that the machine shop had to make a custom spark plug insert. This was screwed in locktighted and pinned to prevent it from pulling out later. Good idea, no?
   
   Upon removal of the top engine cover, I found the pin had blown out. Apparently the hole it was in was a LITTLE too deep, but NOT into the combustion chamber. I know this as I did a lot of work deshrouding the valve areas and would have seen it. 
   
   My theory is that the combustion chamber pressure blew out a very thin aluminum skin in the combustion chamber and then the pin. This is why it ran well for about 20 seconds then started the hissing sound as the aluminum skin gave and blew out the pin.
   
   I removed the head yesterday. Today the machine shop apologized greatly and said they would put a set screw in and then TIG the screw in and maybe close the end in the combustion chamber. No sharp edges!  
   
   My next question is:  
   Why the clicking noise when  I turn over the engine on the starter. I think I'll secure the left cylinders, remove the fuel pump and deactivate the ignition and see if I can duplicate the sound with the left head off.
   
  

BobHelt at aol.com wrote: 
  
In a message dated 5/17/2006 2:45:24 PM US Mountain Standard Time, 
kovacsmj at sbcglobal.net writes:

Anybody have any thoughts on any other diagnostic trick to be used before I 
pull the left side off? I wont pull the whole drive train again. I don't have 
a bore scope to look into the cylinder.



Check for pulled head stud.
Regards,
Bob Helt


MIKE KOVACS


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