1989 Bronco II. Compression test results. Higher on one side of the engine


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Joined
Mar 16, 2025
Messages
5
Points
1
City
Iowa
Vehicle Year
1989
Transmission
Automatic
Hey all,

Did a compression test on my 1989 Bronco 2. With the 2.9l v6. Results are as following:

Cyl 3: 170 psi | Cyl 6: 165 psi
Cyl 2: 180 psi | Cyl 5: 165 psi
Cyl 1: 180 psi | Cyl 4: 160 psi

I found it weird that the compression was noticeably higher on one side. 180 also seems like its unusually high for this engine.

Any thoughts or does this look good?

Thanks!
 
I'd say its good.
Did you happen to start with #1 and end at #6? If so, the battery getting depleted might have something to do with those readings.
 
10% highest to lowest is acceptable. So your pretty close.

Are you having running issues?
 
10% highest to lowest is acceptable. So your pretty close.

Are you having running issues?

No running issues I just thought it'd be a good idea to check. I do have bad valve stem seals for sure though. I am changing those next week. Blue smoke out the exhaust when starting the engine for a couple of seconds. No smoke after.
 
No running issues I just thought it'd be a good idea to check. I do have bad valve stem seals for sure though. I am changing those next week. Blue smoke out the exhaust when starting the engine for a couple of seconds. No smoke after.
Yeah those numbers are totally normal....and pretty damn good.
 

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