Smoke on startup

[cookin86]

Recently my 86 has been smoking on startup. I would have thought maybe it was the valve seals because I know they are known for it, but this morning I noticed something else. It only smokes out the left (drivers side) exhaust. Not a thing comes out the passenger side. Or if it does you can't see it.

Not even really 100% sure it's oil. Up until this point I thought it was for sure, but now that I think about it. It has a little bit of a sweet smell. Like antifreeze maybe. Oil and water look good. No spots in the oil. No Milk in the water. So I don't think it's a head gasket. Could it be from the turbo, and why only the left side exhaust?

As always any help would be appreciated.

[svobud]

The exhaust is not a true dual. (dual tail pipes on a 85.5/86) It starts off a single pipe, then after the converter - it splits at what's called a Y pipe, that goes into two separate pipes to mufflers, then tail pipes. The whole exhaust has bends and turns in odd places. Even the Y pipe has a funky split angle to it - which might explain why you're getting the heavy mixed exhaust only on one side.

As for the contents what you're seeing. Headgaskets can have small breaks between cylinders - that seeping might show up in your exhaust and not your oil. If you suspect you're having headgasket issues, do a compression check.

Smoke only on start up is a common sign of valve stem seals needing replacement.

[GAboySVO]

What color is the smoke? Blue=oil, white=anti-freeze, black=gas.

[cookin86]

What color is the smoke? Blue=oil, white=anti-freeze, black=gas.

It looks white to me.

And it smells to me much like when you have a bad heater core and you leak hot antifreeze on the floor board. So I agree it could be water. If it were a head gasket though I would think it would continue throughout driving and not just on startup.

The turbo is water cooled correct? Is there a seal in the turbo that could be bad? Letting water pass through until it heats up and seals? I know that's probably reaching a bit.

I know the exhaust is a y-pipe so that's why the smoke out one side really throws me.

[svobud]

It looks white to me.

And the results from your compression test?

I know the exhaust is a y-pipe so that's why the smoke out one side really throws me.

If you know the exhaust design, then you should understand how the stock Y pipe has one pipe that is a straight shot to the tail pipe, and the other juts off without fluid design = Flow follows the path of least residence.

[GAboySVO]

It looks white to me.

If it were a head gasket though I would think it would continue throughout driving and not just on startup.

I would agree with you in general, but as Bud says, a compression test will confirm or eliminate that possibility.

In general, all cars will "smoke at start up" when the air is cold and humidity high. Just like an air compressor that build up water in the tank when operated, the air compressor under your hood (engine) is doing the same thing and steam (water vapor) is released from the tail pipe.

[cookin86]

And the results from your compression test?



If you know the exhaust design, then you should understand how the stock Y pipe has one pipe that is a straight shot to the tail pipe, and the other juts off without fluid design = Flow follows the path of least residence.

Okay I gotcha. I was aware of the general y-pipe design. I was not however aware that one pipe went straight out and the other came off of it. I made an assumption that they had a equal split. You know what they say about assumptions.

I agree a compression test is an easy way to see if it's a blown head gasket.

[cookin86]

I would agree with you in general, but as Bud says, a compression test will confirm or eliminate that possibility.

In general, all cars will "smoke at start up" when the air is cold and humidity high. Just like an air compressor that build up water in the tank when operated, the air compressor under your hood (engine) is doing the same thing and steam (water vapor) is released from the tail pipe.

I will do a compression test. Although I really am leaning towards it being something from a seal in the turbo. I've suspected I have a turbo issue for a while. I have boost issues as well so at some point i'm sending this turbo off to Evergreen. But if compression doesn't look good then I guess I know what i'lll be doing first. Crossing my fingers for the turbo.

I do know that condensation in the exhaust will vaporize and cause smoke or steam, but I know that's not what this is. In that case it would most certainly come out of both pipes and would almost definately not have an odor. At least not one like this.

I do appreciate your help.