2.3 compression readings

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2.3 compression readings

Postby pchicky » Tue Mar 29, 2016 4:14 pm

OK, I am new to the forum and somewhat new to the standard Vega, although I do have a Cosworth, so my knowledge isn't zero on the vehicles. Anyway, I am the proud new owner of a 1974 woody wagon with 34k original miles on it. Before I bought it, I ran compression tests on all four cylinders and got 152 on cylinder 1, 153 on cylinder 2, 123 on cylinder 3, and 152 on cylinder 4. Hmmmm, so cylinder 3 plug did show a small amount of oil residue around the edge but it wasn't an oily mess per se....it was just blacker, but not wet black. I have been told that the 120 psi isn't abnormal for this engine, but it is less than the other three cylinders and ideally having all three the same is a good thing. The car does blow a little smoke on startup, but then stops after warmed up....it's blue, not black, so there is some oil burn in there, but it isn't bad like birds falling out of the sky or anything.

Is my puppy sick and need a tear down, or is 123 PSI satisfactory for this engine?
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Re: 2.3 compression readings

Postby rpoz-29 » Wed Mar 30, 2016 9:27 am

I would drive it. It would be a good idea to locate the parts for a rebuild if your plans are to keep the car. Parts for these engines are getting really hard to find. Does it puff a little smoke between shifts? (assuming it's a manual transmission)? Valve seals will leak a bit of oil into the combustion chamber too.
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Re: 2.3 compression readings

Postby pchicky » Wed Mar 30, 2016 6:42 pm

It's an automatic, and no, there are no smokes between shifts......just seems to be some oil burn off during start up and warm up right now......I've got a 16K mile Cosworth motor sitting here....hmmmmm.....but that takes changing tranny and rear end and making it a manual....the car is so nice I'd like to keep it factory original.

Yeah, I think I'll just drive it and continue to monitor compressions every now and then. Supposedly the motor was sleeved by two owners ago in 2002 when it had about 32K miles on it, but no documentation to prove it.
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Re: 2.3 compression readings

Postby Kenova » Wed Mar 30, 2016 9:31 pm

Put a new timing belt on it, keep good oil in it and beat on it like a rented mule.

Ken
My other car is a Nova.
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Re: 2.3 compression readings

Postby hammerdown7 » Wed Mar 30, 2016 9:51 pm

Paul,
Welcome to the h-body site! I agree with Bill's comments.
Dick
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Re: 2.3 compression readings

Postby kgroombr » Thu Mar 31, 2016 6:47 am

Oil burn off on start up probably means valve seals need replacing. This is a common 140 problem, and replacing them isn't too hard, but you need to remove the camshaft and that takes a special tool which is getting somewhat hard to find.

Ken
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Re: 2.3 compression readings

Postby monzabug350 » Thu Apr 07, 2016 9:06 pm

If you are not in a hurry to lay wrenches on it, you may want to try an additive I came across a few years ago. It is called Marvel Mystery Oil. I have used it in my Daytona and my chevy Cav 4 banger. After using it for the past 2 years I found the chevy eng looks like it was built yesterday inside.There is no gunk buildup inside and a little lifter tick was gone after 2 oil changes. Same for the Daytona. Plus it can also be added to the fuel system as it cleans injectors as well, and you get a little better gas milage. I got mine at Dollar General for 3$ for a 16 oz bottle and you can also get a 32oz bottle for 6$ here in va beach, which beats the auto stores double price for the same bottles. It also softens the rubber seals for the valve guides. You just add 1oz to 10 gal of gas or more if you want. I was getting about 80 to 90 mpg before using it and now I can easly see 100 to 130 mpg.(No shit batman) Oh, I got the cav as a used car with 46k on it and have had no trouble so far. You have nothing to loose except 3$. Give it a try and see what happens. P.S. It comes in a red bottle with a black label with white letters on it.
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