CJ3b smokes but compression is good?

[kickitandholdit]

I sold my last jeep a few years ago so I have not posted on this forum in a long time. I just bought a 1953 Cj 3b so i'm back!

My first problem I need to fix is that the engine smokes after running for a minute or two. Cylinder compression is between 120 and 130 on all cylinders. All cylinders hold pressure.

This makes me think oil maybe getting into the intake valves somehow or something that I'm not familliar with.

What are things I can check and look into?

Thanks in advance and I'm glad to be back on the jeep forum!

Cheers,

 

[Posi]

Welcome back
F-134?
Is the smoke blue, black, white?

Pics of your tall hood would be sweet, I've owned three in the past.

 

[kickitandholdit]

Welcome back
F-134?
Is the smoke blue, black, white?

Pics of your tall hood would be sweet, I've owned three in the past.

It's hard to tell not having much experience with smoke. At times I'm like oh that's "blue smoke" but it doesn't have a strong oil type smell which makes me question my judgment. I figured if there was a cracked head gasket and it was burning water that would show up in the pressure test. Maybe I'm wrong.

I will try to post some pictures tonight

 

[Posi]

Does it have the original F134 Hurricane engine?

 

[kickitandholdit]

Does it have the original F134 Hurricane engine?

As far as I know

 

[kickitandholdit]

Welcome back
F-134?
Is the smoke blue, black, white?

Pics of your tall hood would be sweet, I've owned three in the past.

 

[kickitandholdit]

Welcome back
F-134?
Is the smoke blue, black, white?

Here is a pic. It doesn't smoke much at cold start or idle. Pat the gas and a plume of smoke puffs out. Compression on all four cylinders are 120 plus and hold that pressure.

 

[Lumpy Grits]

Valve guides are worn
What weight oil?
LG

 

[kickitandholdit]

Valve guides are worn
What weight oil?
LG

They guy said 30.

I figure either way the head is coming off. I might pull it and take it to the machine shop for them to check out.

 

[Lumpy Grits]

How long does it put out the smoke?
Can you R&R the valve seals with the head in place?
Check the plugs for fouling.
LG

 

[kickitandholdit]

How long does it put out the smoke?
Can you R&R the valve seals with the head in place?
Check the plugs for fouling.
LG

The plugs were dry and black. My plans for the afternoon got canceled so I pored a cold one and grabbed my wrenches.

The only thing holding the head on now is the gasket. I'm going to save the surprise for the morning. Wish me luck as I crack her open. I couldn't even pick up the valve cover gasket. I had to wipe it off in pieces.

I may have to find that old thread about Previous owner problems. I have come across some good ones on this thing.

 

[Lumpy Grits]

Dry & black is a rich fuel mix.
Make sure you have the correct plugs and the choke opens all the way.
LG

 

[kickitandholdit]

Dry & black is a rich fuel mix.
Make sure you have the correct plugs and the choke opens all the way.
LG

The plugs were rusty and really old. It definitely had been running rich at some point with those plugs. I'm familliar with runnning rich though. It's totally different that what this jeep is doing. I expect valve guides since compression was good. I hope the block or head isn't cracked. Hopefully I can get a gasket set, go through the head and just drive it.

 

[Lumpy Grits]

Fingers are crossed for good luck
Keep us updated.
LG

 

[kickitandholdit]

Fingers are crossed for good luck
Keep us updated.
LG

Ok, so the head gasket was fine. There's a lot of sludge built up and cylinders are thinly rusted. The sludge was all dry except for #4 which seamed oily.

My best guess is that #4 valve seal was leaking or the cylinder wallls being rusty was letting some oil pass. Maybe a combination of both. I read that if it's smoking due to thin rust on cylinder walls that running it will clear that issue up.

My options are to go through the head, have it redone and bolt it back in and drive it or total rebuild. The tops of the pistons are sludgy so having the whole motor rebuilt is a good option but more expensive and not totally needed since compression was high and it ran good. If I get the head done I can be cheap and leave the motor as is. This will allow me to get it on the road a bit to get to know the rest of the jeep and go from there.

While the head is off is there anything I should do? Should I try to clean the pistons and deck or not worry about it? What's the best way to clean it if so? I know I have to clean the deck to get a good gasket surface but is trying to clean the sludge worth the time if I'm not rebuilding the motor?

All opinions and suggestions are welcome!

Ps. The picture of the piston and cylinder wall wasn't originally that wet. There was some leftover antifreeze in the head that fell in that one haha.

 

[Lumpy Grits]

Do the cyl walls feel smooth?
I would reseal all the valves in the head and put it back on.
Get some new plugs, wires and cap & rotor. New points and condenser and have at it.
Run a 15w-40 or 20W-50 engine oil and enjoy.
Clean the head and block with a large flat med file.
Vacuum off all the crud you can. Wipe down all else. Don't be afraid to use some Q-tips for this.
LG

 

[kickitandholdit]

Do the cyl walls feel smooth?
I would reseal all the valves in the head and put it back on.
Get some new plugs, wires and cap & rotor. New points and condenser and have at it.
Run a 15w-40 or 20W-50 engine oil and enjoy.
Clean the head and block with a large flat med file.
Vacuum off all the crud you can. Wipe down all else. Don't be afraid to use some Q-tips for this.
LG

I think that's is going to be my plan. I want to keep this project cheap for now and restore it in a year or two.

The cylinders feel smooth.

Is it a bad idea to soak it down with purple power and clean. I don't want to cause any problems that weren't there to begin with. I hate to degrease anything that might need to be lubercated.

 

[Lumpy Grits]

Wipe down with solvent and keep the weird chems to a minimum. Squirt a small amount of oil into each cyl at the rings before you re-install the head.
Wire brush goes along way here.
Change oil & filter before next startup.
LG