Engine Well Damn - Low Compression

[Airtime]

I've been trying to address a slightly rough idle. Did plugs, wires, adj carb & timing etc. ...finally broke down and bought a compression gauge (evidently I own a leakdown checker but not a compression guage???). Anyway, 7 cylinders read 130psi - 135psi and cyl #4 reads 65psi. Dumped some 15w40 in there and compression went to 90psi. Google says that could be stuck rings and I have now soaked for days different things. I tried mm oil, seafoam, atf, a 50/50 mix of atf & acetone...now still at 65psi.

It runs fine and I drove it 2 hrs round trip a few weeks ago and got 15mpg. I almost wish I didn't know compression is the issue...but now that I do I have to fix it. I'm going to try to do it without pulling the engine. It's got 108k on the odometer but sat for at least the past 10 yrs.

Today or tomorrow I'll start by pulling the intake/carb and passenger side head. I'll look at everything I can from there.

Actually, just now I'm thinking. Maybe I should pull the oil pan 1st. That way I can see the cylinder wall. If it's smooth then pull the head.

Thoughts?

 

[TSB8C]

Agree on dropping the oil pan and check the cylinder wall. If it's scored than you know what needs to be done. If not and it's smooth, then you could just pull the head and check for a broken or stuck ring and make a decision from there.

 

[jzak]

Why you looking for problems bro! Just add some motor honey every once in a while, and you're good to go. Seems like everyone nowadays wants to pull an engine the second you hear some piston slap or rod knock. My dad drove his ford country squire 50K on zero compression. No problems.

 

[Belizean]

My number 4 is a little lower on compression also, but not enough that I’m going to do anything yet either. Not nearly as much as yours though.