White Steam

[2000 Elisa's Ring SR 24]

I run twin mercruiser bluewater 454's in the Chesepeake Bay. Over the past two weeks I have noticed my engine temperature has risen from running temp of 160 to 175. I have a small to medium amount of steam coming from the exhaust as well. Recently the air temperatutre has been well into the 90's and the bay water is in the 80's. I had the impellors replaced and have good water flow. What could be the cause of the steam and is it the temperature of air and water that caused the rise in temp? At idle speed the engines go back to normal 160 degrees anfter a while. Any suggestions?

 

[Don S]

Re: White Steam

Old or damaged raw water pump impeller, plugged hoses, lines, block.
Defective Exhaust manifolds and risers. Plugged with rust and scale.
Plugged block due to scale, rust, sand, mud, and who knows what else. (If a raw water cooled engine)
Could even be ignition problems, is the advance working?
Lots of things could cause it, what sort of maintenance has been done in the past few years? And what year is your engine,

 

[2000 Elisa's Ring SR 24]

Re: White Steam

Old or damaged raw water pump impeller, plugged hoses, lines, block.
Defective Exhaust manifolds and risers. Plugged with rust and scale.
Plugged block due to scale, rust, sand, mud, and who knows what else. (If a raw water cooled engine)
Could even be ignition problems, is the advance working?
Lots of things could cause it, what sort of maintenance has been done in the past few years? And what year is your engine,

 

[2000 Elisa's Ring SR 24]

Re: White Steam

The engines are 1992, the manifolds and risers were pulled, cleaned and check beginning of this season. The manifolds are 1.5 yrs old, risers a little older but they were in good shape. The temperature on the risers are good while running at the 175 degrees. You can touch them and leave your hand on them and be "cool" to the touch.

Why would the igniion cause it, the steam only starts as the engine warms, it is not there at first?