440 smoke

[MWFan]

Ok, I have a smoking problem.
440 does NOT smoke when cold, period.
Does not smoke on startup. At all.
Has 165-175 lbs. compression on all 8.
Smokes at IDLE ONLY, when HOT only.
If I hammer it it DOES NOT VISIBLY SMOKE. Hot or cold, riding down the street, no visible smoke. Highway, no visible smoke.

I have replaced the valley pan and intake gaskets.

Any ideas?
Thx, Bernie

 

[steve340]

Valve guides and the valve guide seals.
PCV system???

 

[cheeseburgerhead69]

Was the engine rebuilt ?? Possibly the rings are not aligned properly... I think if it smokes, oil must be seeping past the rings or Possibly valve seals...

 

[MWFan]

The engine was rebuilt in 1998. If it is rings, why is the compression so high? If it is valve seals, why doesn't it smoke at startup?
I am beginning to think this perfectly functional very strong running big block will have to get rebuilt to figure this out.

 

[steve340]

The compression and oil control are different rings broadly speaking. I saw and engine years ago running on 3 cylinders that had broken top and second rings but burnt no oil at all.
Good compression does not equate to good oil control unfortunately.
I would look at something in the heads or PCV.
What oil do you have in it?

 

[MWFan]

The compression and oil control are different rings broadly speaking. I saw and engine years ago running on 3 cylinders that had broken top and second rings but burnt no oil at all.
Good compression does not equate to good oil control unfortunately.
I would look at something in the heads or PCV.
What oil do you have in it?

Thanks. I have seen broken, stuck and worn compression rings a lot more than any oil ring issues, but it could be. I wonder how accurate the compression test dry compared to compression test with oil might be. I was running Castrol 10w 30 with zinc, just changed to 20w 50 and no difference. The previous owner ran straight 30.
Think I'll pull the heads and look. It may just have dried out seals but I still don't know why it doesn't smoke at startup. A mopar thing? A my GMs did there was a valve so problem.

Thanks.

 

[WP29440SE]

rule out the easiest thing first (as far as mechanical issues go), replace the valve seals. I bet they are as hard as a rock

 

[khryslerkid]

It's not condensation is it? (Have to ask)
Need to determine if it's oil smoke, coolant smoke, rich fuel.

Check your pcv hose at the carburetor and see if it's oil soaked inside.

Don't be tearing things apart until it's properly diagnosed. What do the spark plugs look like? One or two cylinders showing oil deposits?

Obtain a bore scope and look for cylinder scarring that could mean broken rings.

 

[BDF6]

Is it smoking from exhaust or from under hood (like mine JUST started doing today- valve cover gasket...)

 

[MWFan]

It's not condensation is it? (Have to ask)
Need to determine if it's oil smoke, coolant smoke, rich fuel.

Check your pcv hose at the carburetor and see if it's oil soaked inside.

Don't be tearing things apart until it's properly diagnosed. What do the spark plugs look like? One or two cylinders showing oil deposits?

Obtain a bore scope and look for cylinder scarring that could mean broken rings.

Nope, blue smoke and noticable oil usage.
I need to check the pcv hose for sure but I'm betting its oily. My son has access to a bore scope, I'll get it and have a look.

Thanks.

 

[steve340]

You are probably best to get a cylinder leak down test done. I noticed one thing you wrote in an earlier post.
Do the compression test and leak down test dry and preferably warm. Do not introduce any oil - this is only done if you suspect a ring problem and want to "seal" the cylinder.
Also throttle wide open while doing compression test.

 

[MWFan]

You are probably best to get a cylinder leak down test done. I noticed one thing you wrote in an earlier post.
Do the compression test and leak down test dry and preferably warm. Do not introduce any oil - this is only done if you suspect a ring problem and want to "seal" the cylinder.
Also throttle wide open while doing compression test.

I have read that some do a "wet vs dry" compression check to diagnose rings which are marginal.
Thanks.