Checking poo of an animal is an old vets way of telling you its health. The same holds true for boats or cars exhaust. In a car or boat, vapor or smoke coming from the exhaust in different colors mean different things. Here are a few possibilities for the white plumes.
Transmission fluid may be entering the intake manifold through vacuum modulator.
The Fix: Replace vacuum modulator
Cylinder head gasket(s) may be bad.
The Fix: Replace cylinder head gasket(s).
Cylinder head(s) may be warped or cracked.
The Fix: Resurface or replace cylinder heads. (Resurfacing is not a DIY job)
The engine block may be cracked.
The Fix: Replace engine block.
Grey: Valve seals may be worn
Fuel may not be all burned prior to entering exhaust. Bad signs.
Engine uses more oil than normal, and there is some smoke from the exhaust. The oil level is low between oil changes. It appears that the oil is being burned by the engine because of the smoke in the exhaust. You may or may not notice the engine doesn't have the same power as it used to.
Check these things first. Then if you just can't figure it out, try a certified tech and they can tell you in a few moments.
Best of luck here. Todd
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