What would make the P15 engine smoke out the oil fill tube??

[BobT-47P15]

About 3 years ago, before the tornado and recent repairs................the car began smoking

out the oil filler pipe.   We thought the cause of the problem was the fact an old carb I had

put on was dumping gas into the oil -  Dale later determined there was gas in the oil.  He

replaced the old carb with one he rebuilt and has changed the oil a couple times or more.

 

Tonight when he started the engine and ran it for just a very short time...........it began

emitting smoke from the oil fill tube again.   The car has sat for the last 3 years and not

been started during that time....which probably did it no favors.  

 

Any suggestions regarding this issue would be appreciated.  

 

If the engine proves to be too bad now, we do have yet another seemingly good

1947 engine for an eventual replacement.  But would rather not have to go thru

all that.  

 

Thanks for any thoughts or ideas.         

[Frank Elder]

Debris/mouse nest/clogged draft tube?

[Plymouthy Adams]

the draft tube is only somewhat effective at idle as any moving air for it to creative the draft needed to vent the engine would be coming off the fan blade itself.  smoke coming from the fill tube normal is usually a sign of blow by due to worn rings.....as the car has sat for some time you may have a large amount of moisture absorbed in the oil and oil residue within the engine and this may burn off to some degree after coming to a sustained operational temperature and allowed to evaporate.  A higher thermostat say in the 180 verse 160 will help to burn this off quicker and is actually better for the engine in the long run...as it was showing some signs prior and you still ran the car...bring it back to life and operate on the road a few time before making any final judgement

[Don Coatney]

If you place your hand over the open tube with the engine running do you feel any pulsations? Have you done a compression test on the engine? How do the spark plugs "read"?

 

As the rest of your car is "fresh" I would think you would want a fresh engine too.

[Lumpy]

Just exactly how much is it smoking? Some smoke or fumes/vapors will be normal. I'm assuming you mean really excessive. Is it smoking out the exhaust pipe? (in addition to the filler tube)

 

Another possibility, as it has been sitting, is that some of the rings have frozen up, especially if It sat with dirty oil. How long an engine can sit without damage depends a lot on how dirty, or clean the oil was the last time it ran.

 

If that's the case, don't panic. Get some good clean, thin oil in it, and some oil additive made for the purpose of cleaning, or flushing the engine. Add the "stuff", and fresh thin oil, and run the engine per instructions. Maybe give it a couple treatments.

 

Also note and act on suggestions from Coatney, Adams and Elder. !!!

 

Now a worn engine with thin oil, such as 10w40, will sometimes smoke. I hope you are not running such oil....don't answer! Change to a heavier oil. I've bought many an old car that smoked when I got it, changed to a straight Castrol 30wt, and abra kadabra, hocus pocus, motor didn't smoke anymore. Just my experience, not trying to start an oil discussion war. !!!! But do the flushing thing first. Don't just change to a heavier oil at this point.

 

Last resort, pull the heads, hose the pistons with some kind of liquid wrench stuff, and tap on the tops of the pistons with a short piece of 2X4 and hammer. TAP, not bang, whack, or smite.  Let the pistons "soak" for a day or two before tapping on them.

 

I agree with Don. True happiness is a fresh rebuilt flathead engine. It's worth the time and money, and will then last you just about forever.

 

Good luck.

 

ken.

Edited January 28, 2014 by Lumpy

[JerseyHarold]

Have you checked the exhaust for restrictions that could increase the back pressure in the engine?

[Niel Hoback]

Marvel Mystery Oil worked on mine.  Fresh 10-30 and a qt. of MMO took a couple hundred miles, but it stopped the smoke from both ends so I
 assume the rings were stuck with carbon and old oil residue.

[Lumpy]

This is true, it's possible that if you just run the engine for a few hundred miles, with some good "stuff" in the crankcase, the rings will free up, if indeed it's sticky rings. All the "clues" seem to point to that, although we really don't know exactly how much it's smoking, and if this smoke is smoke, or vapor, or heavy blow-by or what. ??? Clarification please!

 

They used to make additives just for this/that purpose, and it worked well on a International Travelall I bought once, that was a smoker, but like Neil it took a few miles, it's not an instant fix. But on a 318 I once knew, where the rings were super gummed/stuck, pulling the heads, and tapping on the pistons did the trick.

 

You could pour some penetrating oil (or make your own "mix" with some MMO, gas, diesel fuel, or whatever else sounds good) down the spark plug holes, let it soak that way. However, it's so easy to pull a flathead that I can't see any reason NOT to do that. Swapping engines, that's another matter, and I'm not sure if swapping in another "seemingly good" used engine is worth the trouble.

 

Re-reading the first post, it might be worth while to run the engine for a LONG time and see what develops. Maybe it just needed to get up to operating temp. ??

 

k.

[BobT-47P15]

Not sure what has happened to the engine.  It ran fine with no issues before I put an old carbureator on it 3 years or so ago.  

Then it started with the smoking (or maybe vapor) out the fill tube.

 

I didn't drive it much after that day, but the next time I started it while sitting in the garage, it began smoking very quickly.

I don't recall that it smoked out the tailipipe - at least not noticeably.  

 

So now, after sitting for around 3 years, son in law says there is a noise too - sort of a squealing thing I think.  

I will listen to it next time I get up to Kansas City where the car is.  That's right at a two hour drive from here.  

 

He wonders if a ring has become un-seated, or stuck, or some such.    I suggested adding Marvel Mystery oil.

He also mentioned putting just a little transmission fluid into the cylinders.   Or, perhaps a rod bearing might be

involved as the gas that got into the crankcase may have thinned the oil.  

 

Am thinking of trying to drive it a little to see if that has any influence on the noise.    He says the engine starts quickly

and easily.  

[Don Coatney]

Suggest you check and lube your generator as that could be a source of the squealing.

[Frank Elder]

Or your water pump might need a squirt....

[Niel Hoback]

      ^{Trying hard not to comment on that last post.}

[Frank Elder]

      ^{Trying hard not to comment on that last post.}

Niel, it was a little tongue in cheek..  ...on the other hand do water pumps with grease fittings squeal when they need serviced?

[Niel Hoback]

  Seriously, yours is a good suggestion, I am just very warped.

[Don Coatney]

I will refrain least wise I will have to stand in the corner facing the wall.

[Frank Elder]

I will refrain least wise I will have to stand in the corner facing the wall.

The thing I like the most squeals while being serviced........Now both Don and Niel ...you guys made me finish that trilogy....

[Niel Hoback]

We're running out of corners to stand in.

[BobT-47P15]

Thanks.  Will try to check those things. 

Edited February 1, 2014 by BobT-47P15