[mikedsilva]

Limited experience here... a couple years ago, I bought a 3.2 engine to rebuild as a project.
I wanted to test run it first so I put it on my test stand... it started and ran 'well'. But after a couple minutes running, it would start to blow a LOT of white smoke.

The next day I started it cold... seemed perfect.. after it got a little heat into it, it blew more and more white smoke. It never cleared so I rebuilt it.

The machine shop found that the valve guides were SO worn, that the valves had so much movement in them, that the seats were concave. Pretty sure this was the source of my white smoke. New guides, new valves and new seats.

After the engine was rebuilt, it ran perfect and never blew smoke.

My understanding is that blue smoke is burnt oil and white smoke is unburnt oil. A bit like a plane signwriting in the sky... not sure if that's a good analogy.


On another engine I worked on, it blew white smoke when the engine got HOT. Turns out that the engine had been sitting for a LONG time and had also been overfilled.. so much that the muffler got oil into it. When the muffler got hot, it made the oil smoke... I changed to a known good muffler and the engine never blew smoke. So in the end, I tried to flush out the old muffler, and then I just ran it and ran it till all the oil was burned out of it!