The Stovebolt Site Forums The Shop Area Engine Shop Another smoking engine....

1953 3100 with a 1954 235.

I bought this truck, but didn't run it before starting a rebuild. I saw videos just prior to buying it, and the truck was running without blowing smoke.

I have the engine back in, and have run it a few times, and only maybe twice up to operating temps. Every time there is a lot of white smoke. Actually, the color and smell is academic as there is oil blowing and dripping from the exhaust.

Ok, so I get it oil is being burned (or not being burned). It didn't seem to prior to this. I'm at a bit of a loss. I hate to jump right into a rebuild....especially in Italy. OR a upper end.

Ok, one confession. Some months ago my wife put gasoline into her diesel car. Fortunately, she called me before driving it. She was on empty before filling with gas. I drained it all into containers, and I'm using that gas in the truck as it isn't put back together, and I can't drive it to the station for fuel. However, there is a very small concentration of diesel in the gas. I can't imagine that can be the issue. However.....

I vote for diesel mixture causing it, although when you say white smoke that in general sounds like water steam.

Oil in the exhaust can come from different things, Loose valve guides, rings not seating, and now from the fuel itself. And if you added oil to the spark plug holes when you did a compression test. White smoke can be steam as mentioned above. And it can be from a very rich mixture. Black smoke is usually oil. Check for water first. Pull the plugs and see if some are dirty, and some are clean. Steam from a crack or leaky head gasket will clean the plugs where the leak is. Watch for water or antifreeze in the oil. That can cause all sorts of expensive harm. If the plugs look about the same, and there is no water in the oil then I would be tempted to run at idle until fully warm with the valve cover off. If the oil turns muddy you have water leaking. if you just get white smoke, try adjusting the carb. It may have a bad float level and that is easy to fix. Drain the fuel out for certain. Use fresh gas, and keep an eye on the radiator level. Just leave the cap off and watch for any drop in the water. The rings may seat if it has not been run for some time. You can get white smoke from water in the muffler as well. That would be from sitting, or from a water leak. One sure way to determine if water is leaking is to pull the dip stick. If the oil level went up you have a leak. Let us know what you find.

Types of Exhaust Smoke:

BLUE SMOKE: Bad news because it means the engine is burning oil. The underlying cause is usually worn valve guide seals or guides, or it may be worn or broken piston rings, or worn or damaged cylinders.

WHITE SMOKE: More bad news because it means the engine is burning coolant or transmission fluid. If the white smoke is coolant, the cause is likely a leaky head gasket or a crack in the cylinder head. If the white exhaust smoke is transmission fluid, the engine is sucking transmission fluid through a vacuum hose to the transmission.

BLACK SMOKE: Black smoke coming out of the tailpipe on a vehicle with a gasoline engine is a sign of a rich fuel mixture (too much fuel, not enough air). A brief puff of black smoke may be visible during hard acceleration when the fuel mixture goes momentarily rich, but under normal driving conditions and idling the exhaust should be transparent. If black smoke is visible all the time and the inside of the tailpipe is coated with heavy black carbon deposits, it would tell you the engine has a rich fuel condition.

On an older vehicle with a carburetor, a rich fuel condition and black smoke can be caused by a stuck or misadjusted automatic choke, a leaky metal or hollow plastic float inside the carburetor fuel bowl, or a fuel saturated foam plastic float, or an incorrectly adjusted float (set too low). A restricted fuel filter may also contribute to a rich fuel mixture.


BLUE SMOKE: Usually smells like burned toast. Check the oil level on the dipstick to see if the engine is using oil and the oil level is low (add oil as needed to bring it back up to the full mark. DO NOT let the engine oil level get too low or serious engine damage will result!. You can also do a compression check or leak down test to diagnose worn pistons or rings.

WHITE SMOKE: The exhaust will have a slightly sweet smell if the exhaust contains coolant, or a burned oil smell if it contains transmission fluid. Check the coolant level and the transmission fluid level. If the coolant is low and/or the engine has been overheating, pressure test the cooling system to see if it holds pressure. If it does not, the head gasket is probably leaking and needs to be replaced. If only the transmission fluid level is low, add the required type of transmission fluid to bring it back up to the full mark, and inspect the vacuum hose from the transmission for fluid inside. If it is passing fluid, replace the vacuum modulator valve on the transmission.

BLACK SMOKE: Check the adjustment and operation of the automatic choke if the engine is an older one with a carburetor. Also inspect the air filter.

Could very well be the diesel fuel. Unburned diesel fuel will cause white smoke. Gasoline engines don't have enough compression to ignite diesel fuel = white smoke

Like Woods stated,Diesel fuel will burn blue,or in heavy concentrations,black. Gasoline burns black if fuel mixture is too rich.Un-burned Diesel white smoke? Transmission fluid burns white. I had a stuck vacuum modulator,in a '65 G.M.C.,and you'd think I was fogging for mosquitos!! Cleaned the valves and top cylinders,though Coolant will cause "white smoke",but actually it's steam,not smoke.

Update.

I had a few minutes to just check a few things.
1. Drained the old gas. I'll buy new gas tomorrow and try that.
2. Checked the plugs. All 6 are dirty, wet, and smell of incomplete combustion. Gaps are correct, plugs are new. I replaced the condenser, and points. I still have to locate a timing light. So, for the moment, timing is a swag.
3. Radiator is still full of fluid.

I had a small head gasket leak and it puffed white vapor which looked like one of those e-cigarettes. Came out and just hung in the air.

Yes, white smoke can be unburned diesel fuel. A friend of mine filled his motorcycle with diesel fuel, ran for about 30 seconds, quit, and when he tried to restart it, nothing but white smoke. Here is more proof
http://www.yachtforums.com/forums/t...ke-vs-white-smoke-both-unburnt-fuel.html

I stand corrected! Thanks for that info!!

Update:

Ok, it was the gas. I got it started with the new gas, and the truck stopped smoking out the mosquitoes. There is still a bit of smoke, but I am attributing that to residual bad fuel, the engine not being timed, and some carb adjustments that might be over my head.