Low Compression, Old motor sitting 20 years Options

[Bartlett 914]

Hi all

I recently picked up a 74 2.0. This car has not run in 20 years. I pulled the gas tank and fuel pump which was a mess. I changed the oil and I pulled the plugs. The compression is even on all 4 at 70 lbs. I know this is quite low. Is this to be expected? Should I try to get it started before doing another compression test or should I just resign myself that this motor must be rebuilt. I does have 88K on it.

Thanks
Mark

[MarkV]

All 4 the same, that is good. Are you holding the throttle open when you do the test?

I would drive it, 88k isn't much.

[Bartlett 914]

Hi Mark

No I wasn't holding the throttle down. I will try that. The battery is also begining to get a little weak. I was never able to get the oil lamp off.

Mark

[Crazyhippy]

depending on how long it's been sitting, it might need some miles to let the rings re-seat to put up a decent compression #...

Sounds like a combination of a weak battery and a closed throttle caused this one though.

Re-check w/ a fresh battery and the throttle WFO

BJH

[Bleyseng]

wedge the TB open while you turn the motor over lots of rpms. A fresh battery helps.
Try a third test by squirting a tad of oil in each cylinder before testing and see if it goes up. (IMG:http://www.914world.com/bbs2/html/emoticons/monkeydance.gif)

[SirAndy]

QUOTE (Bartlett 914 @ Sep 23 2005, 02:29 PM)

This car has not run in 20 years.

just my humble opinion, but *ANY* motor that has been sitting for 20 years (or 10, or 5 for that matter) should be taken apart before you even try to turn it over.
unless it was stored *correctly* in a climate controlled enviroment where moisture in the air isn't a problem ...

god knows how the internals look like (think RUST) and you might just kill a bearing or two or add some nice grooves to the cylinders from simply turning it over ...
(IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif) Andy

[jd74914]

QUOTE (SirAndy @ Sep 23 2005, 05:45 PM)

QUOTE (Bartlett 914 @ Sep 23 2005, 02:29 PM) This car has not run in 20 years. just my humble opinion, but *ANY* motor that has been sitting for 20 years (or 10, or 5 for that matter) should be taken apart before you even try to turn it over. unless it was stored *correctly* in a climate controlled enviroment where moisture in the air isn't a problem ... god knows how the internals look like (think RUST) and you might just kill a bearing or two or add some nice grooves to the cylinders from simply turning it over ... (IMG:http://www.914world.com/bbs2/html/emoticons/cool.gif) Andy

I'd atleast spray some marvel mystery oil down the spark plug holes into the cylinders.

OT: Is your car the one in your avatar? Cause if it is its a 75 or 76

[Bartlett 914]

Thanks for the input.
I have read several posts about people starting and using motors that had been sitting. I wanted to see if it would run. I have decided to pull the motor. I see too much of a chance to ruin this motor.

The motor is in a project 74 car I picked up. My avitar is my regular car and is a 75. I plan to rebuild this 74 motor and install it in the 75.

Mark

[jd74914]

Ok, that makes sense now. You shouldn't need to rebuild the whole thing. Replacing the rings should give you better compression. (I personally would redo everything so you'll have a new and hopefully trouble free engine)