Did a Compression Test

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May 21, 2001 | 08:37 AM

bluemustang

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From: Columbia, TN

Did a Compression Test

I finally did a comression test on my 360 in my F-100. All of them read about 130 except for one and it read 30 it was the #2, I did the test 4 times. Also the spark plug didn't even look used. Any ideas what the problem is and about how much it would cost to get fixed?

May 21, 2001 | 08:52 AM

73Custom

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From: SD

Did a Compression Test

[font color=red size=2]Sounds like some serious trouble... Try squirting some oil into that cyl and test again. If the comp goes up it is bad rings, if comp stays the same it's bad valve. I would bet on bad valve. In that case you will need to pull the heads and have a valve job done - about $400-$500 for head work - plus price of gaskets and removing/installing the heads. I did this to my 390 last summer, it's not tough if you are somewhat mechanically inclined. Take them to a machine shop and have them install new guides and new hardened seats for sure, plus they will check the valves, springs and surface the heads. Do both heads at the same time...

Marty

"Cleverly Disguised as a Responsible Adult"[/font]

May 21, 2001 | 09:03 AM

bluemustang

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From: Columbia, TN

Did a Compression Test

So, I quess I will be trashing this engine. I can get freshly rebuilt 390 for $700 that a shop rebuit for someone and they never picked it up and the guy just wants his money out of it, for parts. He does a pretty good job, my dad had one rebuilt by him.

Thanks for the info

May 21, 2001 | 10:34 AM

dinosaurfan

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From: SW Michigan

Did a Compression Test

David, for peace of mind, fix the oiling problems in that 390 before you drop it in. 999 out of 1000 machine shops don't do it even though it is very cheap insurance against a spun bearing. If your 700$ special is already assembled, you can still do the passage at the pump if you remove the oil pan, that is the most important one anyway. And what is to become of the 360 when you remove it? If you don't want it any of us that live within driving distance might love to take it off your hands. DF

May 21, 2001 | 10:47 AM

bluemustang

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From: Columbia, TN

Did a Compression Test

I going to see if will make deal with me if he will take some money off if I give him the old 360, if not I will be getting it away for just about nothing. The oil passage you are talking about, is there in direction out there that tell you how to do it? Is it easy for anyone to do?

Thanks David

May 21, 2001 | 11:26 AM

jspegg

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Did a Compression Test

Mine did the same thing and on the number 2 and it was the valve was not seating due to valve seat wear.Fix that cylinder and it started hiting again.

May 21, 2001 | 02:11 PM

dinosaurfan

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From: SW Michigan

Did a Compression Test

David, you can do the oil passage yourself. In less than a half hour you can have the pan back on and be ready to install the engine. To check if it has been done or not, remove the oil filter adapter and check the diameter of the oil passage from the pump to the filter adapter. If it is 3/8s of an inch it needs to be fixed, if it is 7/16s or more it has been fixed. I use a drill bit to check size. If yours needs it I can talk you thru it. DF