Abnormal amount of condensation on startup?

[C.E.Divine]

Hi everyone,

Trying to get my 94 K2500 350 in good operating condition. Upon startup, there is a tremendous amount of condensation blowing out of the exhaust. I have never seem a vehicle blow this much out. It doesn't seem to lose any coolant, and I never get a coolant smell. I am wondering, could this be a sign of a clogged cat and a large temp difference before and after the cat? It seems to go away after 5 or so minutes, but will start up again when the truck is off for 5 or more minutes, but only blows out for a few seconds upon a warm startup. Is it also possible that a small amount of coolant is seeping in to the system somewhere after sitting for an amount of time, but as the engine warms up the leak seals? I have not done a block test to see if there are any exhaust gasses in the coolant because it seems to be such a small issue. But I do not want to let it continue if this is something to be concerned about. The truck is almost to 274,000 miles if it helps. And I cannot remember if it does this in the summer, because I drove it so little before it came in to my possession in May and then sat until just recently.

 

[90W7]

Hi everyone,

Trying to get my 94 K2500 350 in good operating condition. Upon startup, there is a tremendous amount of condensation blowing out of the exhaust. I have never seem a vehicle blow this much out. It doesn't seem to lose any coolant, and I never get a coolant smell. I am wondering, could this be a sign of a clogged cat and a large temp difference before and after the cat? It seems to go away after 5 or so minutes, but will start up again when the truck is off for 5 or more minutes, but only blows out for a few seconds upon a warm startup. Is it also possible that a small amount of coolant is seeping in to the system somewhere after sitting for an amount of time, but as the engine warms up the leak seals? I have not done a block test to see if there are any exhaust gasses in the coolant because it seems to be such a small issue. But I do not want to let it continue if this is something to be concerned about. The truck is almost to 274,000 miles if it helps. And I cannot remember if it does this in the summer, because I drove it so little before it came in to my possession in May and then sat until just recently.

What's the temperature roughly where you are? Id lean more toward condensation however given the milage you could be right as far a very very small coolant leak when the engine cools.

 

[C.E.Divine]

Temperature today was mid to upper 30's.

 

[90W7]

Temperature today was mid to upper 30's.

Is there any cross contamination of fluids such as coolant in the oil?

Oil on Dipstick look milky at all?

I would take the radiator cap off, run the engine up to temp and look for bubbles in the radiator. (coolant loss theory)

Also another theory/possibility could be to check the little drain hole on your muffler. If it were to become clogged or rusted/restricted your muffler will hold water.

 

[C.E.Divine]

I haven't noticed any cross-contamination in the oil, and the guys that did the oil change didn't say anything about milky oil today. I'll do the coolant cap thing tomorrow. And if it is the drain hole on the muffler....new exhaust from the manifold back goes on Thursday. So if it is still an unresolved issue after those steps, I will keep looking.

 

[90W7]

Awesome, let us know how it goes.