White smoke in the tail pipe

I have a 2004 Nissan Pathfinder with 61K miles. It started to spew white smoke from the tailpipe about a month ago. I’ve had 4 mechanics look at it. The Nissan dealership said that I had sludge in the engine and needed to replace the engine. Another mechanic said that I had a crack in the engine, another said that it was fine and that I just needed to change the oil every month for the next 6 months. I’ve read online that the white smoke is burning anti-freeze. I don’t know which of these answers are correct or not. Can anyone advise? Thanks!

White smoke is water/antifreeze. It’s NOT a good sign. If it just started all of a sudden and doesn’t go away…then it could be a cracked head or blown head gasket. Have you checked the water level in your radiator?

Who ever said it was sludge is an idiot. Do NOT go back to that dealership. This should not be a very hard problem to diagnose. Check oil and water levels. Pressure test the radiator. But it is something that should be addressed.

Did anyone do any tests? You read correctly: this is the sign of coolant in the combustion chambers, usually due to a blown headgasket. Have you been using coolant?

Whatever it is, it’s bad, but you may not need a new engine. In older cars with a vacuum control on the transmission, a rupture of the diaphragm in the controller would allow the engine to suck in transmission fluid, resulting in a white exhaust. Immediate repairs ususally did not result in engine damge.

Similarly, a head gasket leak or cracked enginew block or cylinder head would have white “smoke” come out of your tailpipe. You need to see a good, independent mechanic immediately, and get a proper diagnosis. All three “experts” you talked to are guessing since they appear unable or unwilling to do a proper investigation.

In any case don’t drive the car much further!!!