There's only three possible sources of smoke coming from a tail pipe. The most common is oil burning. That usually shows up as a bluish or darker smoke. Coolant always is white with a sweet odor. The third and most rare, is transmission fluid. And that's always mixed in with coolant.
The reason it's rare: most cars have transmission cooler lines running to the radiator. Sometimes the radiator will develop an internal crack that allows tranny fluid to mix with the coolant. Then if there's also a blow head/intake gasket, both fluids will burn out the tail pipe.
Tranny fluid will always burn white as well, but much thicker.
As for your problem, when you drove your car, did you get on the highway with speeds in excess of 50-60? The reason I'm telling you the car may not necessarily overheat is this:
I recently had an Olds Aurora with a 3.5 V6 and a blown head gasket. There's no question I knew what the problem was, but I couldn't fix it right away.
Knowing what I know, I stayed off the highway, kept my sustained speed under 50 and made sure the fluid was always topped off and bled of air.
I could drive around for hours without overheating.
So back to your issue. Pull the resevoir cap, and while someone revs your motor up and down past 1500 rpms, look at the coolant and any signs of large bubbles. If there's any, you have a blown head gasket.
Next dip your finger in the tail pipe and smell it. If it's sweet, blown head gasket. If it's oily, you're burning oil.
If you eliminate the coolant as a possible source, do a compression check on each cylinder. This'll tell you if it's oil and where it's coming from.
Keep in mind, after so many miles, all motors wear internally and begin to smoke from the tail pipe.
Monday, November 22nd, 2010 AT 11:01 PM