Compression Test Result Help

[Discoman]

As some of you have read in my thread below, I am looking at a 1978 FJ40 with a stock drivetrain. Thanks to suggestions below, I had a mechanic take a look at the rig and do a compression check. I'm still waiting for the report to get the exact numbers but he told me the compression readings averaged about 120; however, two cylinders read 90 & 100 (I believe the highest was 140ish). I'll edit & post the exact numbers when I get them later today. How bad is this reading? I know the factory spec is all cylinders within 10% of 150. Am I looking at a swap/rebuild pretty quickly? I haven't driven it yet but the mechanic says it drives fine.

Lastly, the current owner says he is having cooling problems in traffic. Could these be related?

Thanks in advance,
Lance

 

[jwest]

Factory spec for compression is:
149 psi standard
114 psi limit
and less than 14 psi difference between cylinders.

Do a wet compression test to check whether you're dealing with rings or valves. An increase in compression figures point to rings.
Your mechanic will know how to do this.

.

 

[Discoman]

Thanks. The actual readings were:

1-128
2-120
3-90
4-150
5-100
6-120

These reading and evidence of a general lack of maintenance (leaks everywhere, needs knuckle rebuild, frame rust, etc) made me decide to keep looking.

It's hard to be patient. . .

Thanks again,
Lance

 

[petescoffee]

Do a wet test or leak down test. It may need just a valve job.

 

[redrustbucket]

Sounds like p/o neglect put a hurtin' on that ride. Try offering less $$. You may get it for a steal now that you know that it's tore up. I'd hate to see somebody get ripped off on e-bay with that thing. It sucks i tried it -once!

 

[Discoman]

I agree with you regarding the ebay thing. Looks to me like the PO just drive it with zero regard to maintenance. I passed on the rig am still looking.

Thanks,
Lance

 

[Romer]

wise move not to hurry in. There are lots of nice cruisers out there.