Compression check numbers ??

MDH33

 
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Jul 5, 2005
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Ames, IA
I just had a compression check done on my FJ60 2F. I'm a little concerned with the numbers:

1 2 3 4 5 6
120 120 110 110 105 120

How serious is this? I did a search looking for optimal numbers but couldn't find anything. :confused:
 

MDH33

 
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Ames, IA
Thanks for posting the link to that thread, I hadn't seen it.

So it sounds like my lower than expected numbers are not unusual since the test was done at about 5500 ft elevation. I was expecting numbers in the 140's but had consistant 120's. The number 5 cylinder which was about 15 psi below the others is a bit troubling but not fatal? I need to find out if they put any oil in the cylinder to see if it is rings. It had a valve job and new head gasket less than 10000 miles ago.
 

chitown40

 
 
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Buffalo Grove, IL
Make sure the engine is warm and the throttle is wide open and you have a good charge on the battery. <-- This is all per the FSM. Has your 2F been rebuilt before, or has the head been done? Hopefully your problem is worn valves, as that is the easier and less expensive fix. Good luck.
 

MDH33

 
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It blew a head gasket about 10,000 miles ago. Had a valve job and new gasket at that time.
 
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I think a good number in Denver would be right around 120-125 psi and at sea level the same engine would show 145-150psi.

Good call Chitown about trying to retorque the head bolts (easy to do when you check the valves). My friends engine on is taco went toast after his rebuild since the head bolts came loose cause they told him he didn't have to retorque the head bolts after 10K.
 

chitown40

 
 
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Buffalo Grove, IL
I never considered the altitude difference as a compression factor, since the FSM never mentioned it. But like Norcal said you may be ok.
 
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