Engine Smoking

73survivor · June 15, 2006

My son just bought a 1990 Work Truck 4.3 V6 with 47,000 original miles. The truck has sat for the past 3 years. When he started it up it didn't smoke but after going down the road about a mile light colored smoke started pouring out of the exhaust.

By the time we got home, (about 10 miles) it had pretty much stopped smoking. It also has a slight miss. Any ideas what it could be? Thanks in advance.

larry arizona · June 15, 2006

My son just bought a 1990 Work Truck 4.3 V6 with 47,000 original miles. The truck has sat for the past 3 years. When he started it up it didn't smoke but after going down the road about a mile light colored smoke started pouring out of the exhaust.
By the time we got home, (about 10 miles) it had pretty much stopped smoking. It also has a slight miss. Any ideas what it could be? Thanks in advance.

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Sounds like it is burning coolant. White or light colored smoke indicates water in being burned. Check coolant level as it will obviously drop if the engine is consuming it. Also pull the plugs and it will be very obvious which cylinder is leaking.

Could be an intake or head gasket leak. Not too bad to repair either.

snoman · June 15, 2006

My son just bought a 1990 Work Truck 4.3 V6 with 47,000 original miles. The truck has sat for the past 3 years. When he started it up it didn't smoke but after going down the road about a mile light colored smoke started pouring out of the exhaust.
By the time we got home, (about 10 miles) it had pretty much stopped smoking. It also has a slight miss. Any ideas what it could be? Thanks in advance.

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Sounds like it is burning coolant. White or light colored smoke indicates water in being burned. Check coolant level as it will obviously drop if the engine is consuming it. Also pull the plugs and it will be very obvious which cylinder is leaking.

Could be an intake or head gasket leak. Not too bad to repair either.

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I tend to think otherwise here. Since engine has set for a while it make have just been some oil the was being burned as the pings reseated and the miss if from the plugs fouling out a bit. It is not unusual for a engine that has sat for a while to smoke a bit which is okay as long as it stops after a while. If it keep the routine up it is more cause for concern than a one or two time event.

ken1mod · June 15, 2006

I think both previous posts have merit. my advice is not to jump to conclusions. If it is losing that much coolant, the radiator will empty quickly. If it all settles down after a few days, relax and enjoy.

Ken

TEE · June 15, 2006

I'm gonna' say valve seals if it stopped smoking after a while and it had been setting that long. Check all the fluid levels after driving it awhile and if there's oil consumption...you may want to replace the seals.

snoman · June 15, 2006

I'm gonna' say valves seals if it stopped and it had been setting that long. Check all the fluid levels after driving it awhile and if there's oil consumption...you may want to replace the seals.

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I would drive it for a while first and do change the oil in it right away and get some fresh oil in it (10w30 not 5w30)

73survivor · June 15, 2006

Thanks for the replies, I checked coolant level before we drove it and it was full. I will keep checking it. I'm going to change the plugs and see what they look like. I'm hoping the rings are just reseating. I'm going to drive it a few days and see if it keeps smoking. I'll let you know in a few days how its working.

73survivor · June 15, 2006

I'm gonna' say valves seals if it stopped and it had been setting that long. Check all the fluid levels after driving it awhile and if there's oil consumption...you may want to replace the seals.

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I would drive it for a while first and do change the oil in it right away and get some fresh oil in it (10w30 not 5w30)

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Snoman, why 10w30 instead of 5w30? The manual calls for 5w30. Just curious.

ken1mod · June 15, 2006

I have never been in favor of thin oils particularly in hot climates. i tend to use 10 30 in summer and 5 30 in winter. Old school, I suppose.

i know you 5 30 guys are probably correct but oil does provide a certain amount of "cushioning" and almost any engine will use less heavier oil than thin.

I think those of us that work our vehicles hard in hot weather benefit from slightly heavier oils. We always used straight 30 in our work trucks in phoenix and had absolutely zero problems. Of course that would never work in cold winter weather.

I am influenced by the manual that came with a medium duty (c-60) chev dumptruck with the truck 350 (steel crank, really cool, looked like stainless) that said under no circumstances use anything other than sae 30, even in alaska. (engine heater required)

Ken

larry arizona · June 15, 2006

I have never been in favor of thin oils particularly in hot climates. i tend to use 10 30 in summer and 5 30 in winter. Old school, I suppose.

i know you 5 30 guys are probably correct but oil does provide a certain amount of "cushioning" and almost any engine will use less heavier oil than thin.

I think those of us that work our vehicles hard in hot weather benefit from slightly heavier oils. We always used straight 30 in our work trucks in phoenix and had absolutely zero problems. Of course that would never work in cold winter weather.

I am influenced by the manual that came with a medium duty (c-60) chev dumptruck with the truck 350 (steel crank, really cool, looked like stainless) that said under no circumstances use anything other than sae 30, even in alaska. (engine heater required)

Ken

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Ken, 5W-30 and 10W 30 are the same viscosity once the engine is warmed up. They are both 30 weight oils at temp. So they are only different when cold and that is for a very short period of time at start-up.

snoman · June 15, 2006

I have never been in favor of thin oils particularly in hot climates. i tend to use 10 30 in summer and 5 30 in winter. Old school, I suppose.

i know you 5 30 guys are probably correct but oil does provide a certain amount of "cushioning" and almost any engine will use less heavier oil than thin.

I think those of us that work our vehicles hard in hot weather benefit from slightly heavier oils. We always used straight 30 in our work trucks in phoenix and had absolutely zero problems. Of course that would never work in cold winter weather.

I am influenced by the manual that came with a medium duty (c-60) chev dumptruck with the truck 350 (steel crank, really cool, looked like stainless) that said under no circumstances use anything other than sae 30, even in alaska. (engine heater required)

Ken

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Nice comment Ken. I agree to that 5w30 is not best choice here for basically the same reasons. Also 5w30 by its nature has more VI in it (Viscosity Improver) which adds no lubercation properties to oil (actually take a bit away) and it make oil more unstable above the 200 degree SAE30 test temp and engine oil is usual well above 200 especailly in bearings and such on a hot day. (you will never see 5w30 recommanded for a diesel because of concerns over oil film rupture)

sjspor · June 16, 2006

You know what, if that thing sat for 3 years, and only has 47000 miles on, your just going to have to run it and see what happens. For sure your gonna puff blue smoke on start ups until the valve guide seals get wet, hopfully none tore when you started it up the first time from being dry.

BUT... put new fluids it. I can't imagine what sitting 3 years has done to all the engine seals, the water pump seal, A/C, tires, calipers/wheel cyl.

73survivor · June 16, 2006

After running it for two days it has quit smoking considerably. Only smokes a little on start up and very little while running. I put new plugs and wires in and changed the oil. Runs like a new one now. The #1 cylinder plug was black and all the rest were tan colored. Right now I'm going to keep running it and keep a close eye on the fluids. I'll keep you posted. Thanks for all of the replies!