White / Grey Smoke Issue

[Floridaman904]

I have a 2022 Mercury 150 4 Stroke (SN: 3B227630) with less than 60 hours, regularly used in brackish salt/fresh water, that produces a fair amount of white / grey smoke out of the exhaust port and even some mildly seeping out of the water flush port area of the engine cowling (yes, I have the flush cap screwed on tight) whenever I slow down after running it above 3000 RPM for more than a few minutes.

I have VVM and it has no alarms or faults are indicated. The engine oil level is right in the middle area and does not appear to be decreasing enough to be noticed and the engine is always stored fully tilted up, on a lift after being flushed with fresh water for at least 15 minutes. However, the engine temperature has also never climbed above 137 degrees and I see folks here indicating I should expect to see >155 after using it above 4500 RPM. I have removed the engine cowling and there does appear to be a small amount of white salt type deposits on cylinder 3 & 4 of the head area but no other water leaks detectable. So how serious is this? Does it need to go back to the dealer right away or can I keep using it to the first 100hour maintenance check?

[Pulsare2020]

Are the salt deposits around the head gasket area? I would get it checked out. If the oil level is constant, there is the possibility that the head gasket has been compromised. I don't know where the coolant passages run on the 150, but Don will chime in. If some coolant water gets into cylinder 3 or 4 or both, the "white / grey" smoke might be steam from water burned in the cylinder. I have about 110 hours on a 300R and the temperature has always been between 135* - 145* depending on the time of year and water temperature. Most of the time it stays around 140*F. Not sure how the thermostat temps compare between the V8's and 150 or if the 150 has a poppet valve. Mine has never been over 145*F no matter how hard it was run.

[EuropeanAM]

Smoke coming from the idle relief port like that is NORMAL.

It is NOT normal to see smoke coming from the flush attachment port, however.

Perhaps pictures or video (video has to be posted elsewhere and provide a link) would prove helpful.

DON'T continue running the engine if you see leakage from the coastal flush port.

Note: Temps are relatively normal, in warmer water temps they may be higher.