1994 4Runner 3.0 Automatic. 216xxx miles.

About 2 months ago, I noticed during startup I was getting a little bit of white/cold morning smoke. Not necessarily thick white smoke, like you would see with a blown head gasket but more of a early cold morning smoke. I initially thought, my head gasket is starting to go. But, that seems to be the only symptom that the car has, and now that it's getting cold I can't tell if it's the exhaust because it's cold or the head gasket is compromised.

I keep a close eye on the oil, and the coolant. The oil has absolutely no signs of water contamination. I've checked the cap for the milky emulsification, there is none. And the coolant does not have significant bubbling. Though the coolant does rise and fall pretty significantly prior to the thermostat opening.

My question is: could I have a blown gasket, experience no overheating, no water oil contamination, and possibly only light smoke during start up..none during regular operation (driving). Also the smoke happens after every startup even when warm but will go away once it comes up to operating temp or about 5 minutes of running.

A couple of things I thought could have occured, were bad valve seals and possibly worn piston rings.

The truck has not lost any significant power and other than the white smoke I have zero issues with the truck. Both AC and heat work correctly. And as I said before zero overheating issues.

The exhaust does not smell sweet. But I do get some water droplets coming out of the exhaust when I warm it up in the morning.

Oh additionally, I've had to put water and oil to top off both the reservoirs. I generally refill them once every three weeks with maybe a cup of coolant and a quarter quart of oil.

 

Mine's an '89 22RE 190,000 miles. Uses coolant. Can't figure out where its going. Its winter, so expect water mist from the tailpipe from cold start. looks like more than expected/normal mist. Even lots of mist when start after 30-45 minutes cool-down. I'll bet its the gasket on its way out. Taking to my favorite mechanics day after tomorrow. Too old to be messing with a job like this. Good luck on yours.

 

It sounds like you are experiencing some coolant loss. I would make sure you don't have any visible leaks in the cooling system.

You can usually rent or borrow a cooling system pressure tester to help you find a leak. If there is a leak into a cylinder, you might see a little coolant coming out of the bad cylinder when you remove the spark plugs.

It is normal on a cool day to get a decent amount of steam out of the exhaust before the exhaust heats up. Water is a byproduct of combustion, so under cool conditions the water vapor created by the combustion process and condenses in the relatively cool exhaust.

 

The chemical block test works well on the 22r. If there’s exhaust gas present in the cooling system, which would be indicative of a failing head gasket, the fluid will change color fairly quickly.