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4.0 engine tested bad...HELP

Old 01-19-2008, 02:45 AM
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Default 4.0 engine tested bad...HELP

Help Help Werird blown up 4.0L


We have a 6cyl 98 jeep, 4.0.
runs bad, compression low. Head replaced with used with all new gaskets.
jeep still runs like crap.
We did a compression test tonite.
1) 25 lbs
2) 27 lbs
3)98 lbs
4)96 lbs
5)50 lbs
6) 52 lbs

WHat gives? why did this motor blow up so perfect?? im new at this game so any insight would help.
Also we added oil to cyl. no change in compression.
s_vares is offline  
Old 03-11-2008, 11:34 PM
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Default Re: 4.0 engine tested bad...HELP

first was the used head psi tested? get urself cylinder leak down tester that way ul know where ur losing ur compression from its the fastest way i know
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Old 03-20-2008, 12:17 AM
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Default Re: 4.0 engine tested bad...HELP

Maybe you tightened down the rockers too far. I did that once after rebuilding a chevy six cylinder. I didn't check the compression, but it didn't run very well until I loosened up the rockers.
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Old 04-24-2008, 09:53 PM
Join Date: Apr 2008
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Default Re: 4.0 engine tested bad...HELP

3)98 lbs
4)96 lbs

Weird , somehow the compression is leaking out somewhere.

Try adjusting the rockers and see if that helps.
Truggy is offline  
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