fot
[Top] [All Lists]

generic question on compression checks

To: fot@autox.team.net
Subject: generic question on compression checks
From: "Brad Kahler" <brad.kahler@141.com>
Date: Wed, 16 Oct 2002 16:04:10 -0500
Amici,

This isn't really Triumph related (other than its a tow vehcile!) but I'm 
looking for guidance on an engine problem.

We had an engine rebuild in our Jeep last spring and over the 
course of the next year we had over heating problems, lack of power 
and apparent blow-by.

We took it back to the rebuilder multiple times to try and get the 
problem(s) corrected.  Never did have much luck.  However, trying 
to get past the state emissions test last month this almost new motor 
failed miserably.

Here are the apparent symptoms.  OIl in the air cleaner coming from 
the valve cover.  Compression check shows approximately 140-145 
across all 8 cylinders at first.  However on the 3rd revolution of each 
compression check (which is what the manual says to check for) the 
pressure drops to 115-120 but comes back up to 140-145 on the 5th 
revolution.  

This doesn't sound like a piston ring problem to me.  It would seem 
to be more of a bad cam.  The cam shaft was replaced, the heads 
were given valve jobs.  Basically it was a complete engine rebuild.

Any thoughts on what to look for?  Should he just pull the heads and 
cam on the assumption that the rings are probably ok?  Or does this 
sound like a ring problem AND a valve/cam problem? 

Any help on this would be greatly appreciated!

Thanks

Brad

<Prev in Thread] Current Thread [Next in Thread>