The Stovebolt Site Forums The Shop Area Engine Shop 235 smoking insanely

So my friend has a 235 that upon start up shakes very bad on top of that it smokes out of the valve cover and vent tube insanely white smoke for about 10 to 15 minutes. I traced the shaking to the carb but the smoke is still there any suggestions? And as always I greatly appreciate all your knowledge, wisdom and experience.

Is this something that just happened all of a sudden? A little more information about the truck will help.

No its been an on going thing.it runruns great after it warms up but he doesn't want the smoke.

Run a compression test, should answer your questions.

Yeah that's what I'm doing now.ill post the results.

White smoke coming from the crankcase Normally means a spinning rod, cam or main bearing. What is your oil pressure?

Excess blow-by (smoke) is usually an indication of bad rings or excessive wear in the cylinder walls. I have seen the top of the piston with a hole in it or ate away at the edge down to the ring land, just not very likely on a stovebolt 6. A compression test along with a cylinder leak down will probably give you the answer you are looking for. Spun bearings usually begin with some racket and then they progress to oil dripping from holes in the pan.

Oil pressure is at 30 no noise whatsoever and runs like a champ.it just billows the white smoke for the first 10 to 15 minutes and then goes away.

But wouldn't blow by come out of the exhaust and not the ventilation?

Blow-by usually comes out of the draft tube,if lower piston rings are affected. It will smoke out of the exhaust,if the upper rings are not seating,or cylinders are worn beyond the ring tolerance. I hope a water jacket in the head isn't cracked. Coolant may seep into a nearby cylinder,and it will smoke until the head expands enough to seal the leak,and evaporate the coolant. A bad head gasket may produce the same effect.

Leak down test. If it's coming from the head, possible valve guides/seals? Spark plugs are a good indicator also.

all plugs looked good not too rich not to lean nice clean even look.

Spark plugs nice and tan in color? Is one or two a cleaner plug than the others?

Non that are oily?

Blowby is cylinder pressure getting into the crankcase past the pistons and rings, that's why its coming out of the vents for the engine. When you have stuff coming out the tailpipe its being burned in the combustion chamber and then exits through the exhaust valve and out the tail pipe.

Jerry, please fill in anything I missed with my description above.

You pretty much got it covered, Don. Is the smoke bluish, or bright white? If the "smoke" is white, I'd also be concerned about the possibility of moisture getting into the engine in some way. Does it miss or run rough while it's warming up, or put white smoke out the tailpipe? I've seen a leaky head gasket that will seep just a little moisture into a combustion chamber or two and cause a miss and lots of white "smoke" (steam, actually) will be evident right after startup until the moisture is purged out of the combustion chambers. In the early stages of a head gasket leak, there won't be any overheating, just steam after a cold start.
Jerry

Try a radiator pressure test on the engine cold. Two spark plugs cleaner than the others screams "cracked head". Are the "cleaner plugs" adjacent? This could mean leaking head gasket. The pressure test will tell the tale. Good luck. Hope I'm wrong.

Try a radiator pressure test on the engine cold. Two spark plugs cleaner than the others screams "cracked head". Are the "cleaner plugs" adjacent? This could mean leaking head gasket. The pressure test will tell the tale. Good luck. Hope I'm wrong.

Be careful with pressure testing, especially if the truck is running an original-equipment radiator. Most everything produced before the late 1950's had a maximum system design pressure of about 7 PSI. Getting energetic with a pressure tester while looking for a cracked head or a leaky head gasket can hand grenade a radiator or heater core. I like to pump up 5-6 PSI and leave the pressure on overnight, then spin the engine with the spark plugs out the next morning. If coolant is going into a combustion chamber, the plug holes of the affected cylinders will squirt.
Jerry

HRL described exactly a problem I had on a 2006 which overheated from loss of coolant due to loose radiator cap.
Caused a very minor leak in the head gasket, leading to white smoke in the exhaust in the morning after sitting overnight. It went away fairly quickly, once the water which collected in the cylinder overnight burned off. The problem got worse over time resulting in taking it in to have the heads removed and the head shaved to remove a low spot in the aluminum head caused by erosion from driving it too long with a bad gasket.
Carl

White smoke almost always means water in the combustion chambers. Blue smoke means oil in the combustion chambers. Black smoke means carbon buildup in the combustion chambers.

Water can come from a number of places including a bad head gasket, a cracked head, cracked intake manifold, cracked block or condensation from sitting for a long time.

HotRod is right. Be careful about overpressure on the system. You could cause a problem you didn't have before.

well fellas i will tell you that its white smoke steam like.and we did a pressure test with zero drop replaced carb runs smooth.all plugs look good and no signs of water or coolant in the combustion chamber.i looked at the oil and again no signs of water.nothing coming out of the tailpipe.

If it's blowby a compression test will tell.

I have a 49 216 that sat 30 yrs before I got it running. I had the head refreshed but did nothing to the bottom end except break the glaze off the cyl's.
At 1st it had terrible blowby, smoke would pour out the valve cover vents. With usage it's down to practically none now. It still has blowby as evidenced by the huge amount of condensation that collects in the valve cover in cold weather. Theres none in warm weather...

In thinking I could have a coolant leak in the cyl's I added a coolant overflow tank. It not only proved I had no coolant leak but I haven't had to add any coolant to the radiator since. When hot the radiator pukes some coolant into the overflow tank and when it cools off it sucks it back. Constant monitoring has proven to loss of coolant.

Compression testers are cheap and if one likes to work on ICE's of any type it is a necessary tool to have in ones arsenal.

Good luck
Dave

With your descriptions of symptoms, you likely have a tiny coolant leak into a cylinder which is not big enough to affect performance, and would take a while to show a loss in the radiator. A tiny leak will steam clean the combustion chamber and the spark plug. I would recommend you take another look at all of the plugs. Rather than looking for water, look for one of them which is cleaner than the others. If you were to pull the head, you would likely find one cylinder with a very clean piston top.
Carl

My buddy left for the rest of the week so when he gets back we are going to get on it again.thanks fellas.