Smoke out of only one side?

[hbar]

So this morning, I fire up the old girl, and it starts right up, no problems. It was in the low-mid 50s this morning, so a little smoke/visible exhuast out the back isn't unexpected. The car doesn't appear to burn oil, but neither have I driven it enough to really say (I've been driving it non-stop since I got it running last month, but that still only amounts to ~250 miles).

It usually takes ~15-30 seconds before I see anything come out the back, probably because it takes that long for the exhaust to heat up to the point where atmospheric conditions cause it to be visible out the back. The odd thing is that I only saw it out of the driver's side for maybe 5-10 seconds, and then it was only out of the passenger's side, and then eventually it was out of both. By the time I got to the office, which is maybe a 15 minute drive, there was no visible evidence of anything coming out of the tailpipes. On warmer days, I typically don't see anything in the way of smoke/exhaust out the back.

Any ideas what's going on, or if it's a problem?

 

[Sluggo]

What color is the smoke?

 

[daveSanborn]

How many miles on the engine since it's last known rebuild? Without any other information to go by.... it sounds to me like you could have some wear in your cylinders that's allowing warmed up oil (thinned) to enter into the combustion process. Why it's alternating between cylinder banks is a mystery though. Does a "puff" of smoke emit from either exhaust tip upon initial start-up? If so this is a tell-tale sign of worn valve guides.

 

[scedd]

maybe you have 1 bad eye

 

[DAVER]

Culprit is generally valve seals that have hardened and crack allowing oil to pass down the valve stem and valve guide into the combustion chamber. It need only be one cylinder bank to have the issue to cause the smoke and only (generally) when the car is initially started after sitting a while.

 

[AzPete]

While all the above may be true, it also could be simply condensation which looks more like steam and not bluish...that would be oil. Coolant would smell sweet. The one pipe and another could be simply the rate at which they warm up and the condensation dissipates. The fact of a crossover pipe or not can also change how the smoke exits.

 

[hbar]

I'll try to answer all the questions, in no particular order....The smoke did not look bluish. I dont have any knowledge of the history beyond the PO, who had it for ~10 yrs(?? i've had it for 3, and it sat in my garage for nearly all of that time). He did not have it rebuilt. Odometer reads 70k, fwiw. I don't know if there is a puff at startup, I'm usually facing the other direction when I turn the key. Both eyes are good.

 

[blue65coupe]

Crank it and go back there and watch. Smell it also. I'm leaning toward Pete on this one with the condensation. Sometimes it's hard to distinuish between blue and white for some of us so use your sniffer. You'll be able to tell real quick whether or not it's oil or coolant. The alternating (if it's condensation) could just be the difference in the heating of the sides.

 

[camachinist]

Even with a crossover, differing levels of condensation retention can occur downstream and cause variations in the quantity of emissions. Also, when cold, the engine can emit differing levels of water vapor from each bank. Based on the OP, I'd call what he saw condensation evaporation/engine water vapor emission. Combustion produces water vapor. If the car is just idled (like sitting in the garage and run only occasionally) on a cool/cold day, a good amount can condense out in the mufflers. When it's cold, water evaporates slowly. Lots of stuff can happen. Sounds normal to me.