New GMT400 Member Help Please

[1993Z71]

Hey Guys i recently bought a 1993 Z71 Ext Cab 350TBI 242K Running Strong.Motor is Stock Always had Proper Maintenece On Schedual.Since I Have owned and driven the truck it smokes white constantly,sometimes less but usually a thin quickly dissipating smoke.Doesn't really use coolant,Maybe 50ml per 2000 Kilometers.Doesn't use oil,Head gaskets are good cause no bubbles in coolant and oil is clean.What could it be??The truck has no catalytic converter.Exhaust smells very gassy.What could it be?Warm or cold always throwing thin white smoke

 

[thz71]

How cold is it where you are?

 

[1993Z71]

Well In Summer it gets to be about 35 Celcius and in Winter right nowwe can get to -50 Celcius with windchill.Manitoba has a huge temperature range

 

[1993Z71]

How cold is it where you are?

-25 ATM

 

[90W7]

Since you don't have a cat your exhaust will smell a lot more.. I also took the cat off on my 91 k2500.

It doesn't take much coolant to blow white smoke but If your not losing any fluids I'd attribute it to condensation in the exhaust system. Myself Being in alaska I have the same issues but when the system is warm the smoke should go away.

Is it doing it on the summer time too?

 

[1993Z71]

Since you don't have a cat your exhaust will smell a lot more.. I also took the cat off on my 91 k2500.

It doesn't take much coolant to blow white smoke but If your not losing any fluids I'd attribute it to condensation in the exhaust system. Myself Being in alaska I have the same issues but when the system is warm the smoke should go away.

Is it doing it on the summer time too?

Yes it is Blowing Smoke in Summer

 

[90W7]

Hmm. You probably have a small ammount of coolant leaking into the cylinder(s) due to a cracked/warped head when the engine cools. I would smell the exhaust and verify it smells like coolant/ has a sweet taste. If it's a true white smoke.

Now if it's bluish smoke at initial startup that would be worn valve guides/seals. However I'm thinking it's a coolant leak.

 

[1993Z71]

Hmm. You probably have a small ammount of coolant leaking into the cylinder(s) due to a cracked/warped head when the engine cools. I would smell the exhaust and verify it smells like coolant/ has a sweet taste. If it's a true white smoke.

Now if it's bluish smoke at initial startup that would be worn valve guides/seals. However I'm thinking it's a coolant leak.

Thanks for the reply man.No its definitely not burning oil,Its white and my oil hasnt budged for pressure or level.About every month I have put about literally 50-100ml in the overflow so very little, like sometimes not even that much.But as I have heard it doesnt take much for a small amount of coolant to cause smoke.It smells more gassy probably from the catless exhaust system, but it dissipates very quickly (thin smoke) Must just be the coolant oh well . Thanks

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[Horns]

As engines wear the valve seals start allowing oil to seep into the cylinder a bit. It doesn't take a lot of oil at all to blow white smoke all the time.

Are you sure you're losing any oil at all? I only lost a quart every 6 months when mine did this.

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[98_k1500]

Should be able to diagnose this by pulling the spark plugs. Tan plugs-no problem, white plugs- coolant, black plugs- over fuel, oily plugs- self explanatory lol