How much exhaust steam is too much?

[brananders]

After doing some searches to find an answer, I still can't figure out if the amount of exhaust smoke or steam from my 210 is normal and just caused by cool ambient temperatures. I think its excessive, but I'm not sure. Once warmed up my boat's temperature is pretty constant at 175. The steam is worse when on a hard acceleration to pull a skier or boarder and then dissipates quickly but is still noticeable at speed. Is this normal or what should I look for to fix it? Hopefully the pics help.

[h2ohangtime]

I talked to my local CC dealer about this exact same issue yesterday. My 2002 GT40 runs at 170-175* and I have the same issue with the steam...a good amount when you hit it and then it dissipates, but there's still a little at idle most of the time.

He said it was completely normal, and that the GM engines are running at about 175* as well, although I'm not sure what thermostat they're using.

[AirTool]

brananders, can you post the air temp and dew point for the time of day and location you took the pictures?

There might be a weather station nearby on wunderground.com ....choose wundermap.

I think that will tell you the answer either way.

[brananders]

brananders, can you post the air temp and dew point for the time of day and location you took the pictures?

There might be a weather station nearby on wunderground.com ....choose wundermap.

I think that will tell you the answer either way.

Thanks, cool site. The lake is in the interior of BC and closest station I could find with historical data was 50 miles away. The dew point was 41 degrees and the temperature was 57 degrees (man have we had a cold summer up here). I do notice more steam on cooler days. So given this would you assume the steam is normal?

[AirTool]

The dew point was 41 degrees and the temperature was 57 degrees

I was hoping the numbers you reported would be closer together than that. I would generally say that 10 degrees spread should prevent any steam. If you were 2 or 3 apart, I'd expect a bunch of steam.

I'm looking at the pictures and it doesn't look like that much steam to me. Have you put your hand in the water/exhaust stream coming out? Generally at idle, I can hold my hand in mine.

Also, are the other boats on the lake steaming like that? or are you the only one? (only one steaming that is)

[brananders]

I haven't tried putting my hand in the stream when you say that you can hold your hand in yours do you mean its not too hot to the touch? I also haven't noticed other boats steaming, but why would I look, I have the only SANTE on the lake but I'll keep my eye out this weekend. The boat is getting its 25hr service on Thursday, is there anything I should get the service guy to check (he's not the dealer since the dealership is 7 hours away)? Would a damaged impeller cause more steam?

[AirTool]

I haven't tried putting my hand in the stream when you say that you can hold your hand in yours do you mean its not too hot to the touch?

I was in the water the other day with the engine running and (out of curiosity) carefully stuck my hand in the water stream coming out the exhaust. I was not nearly as hot as I thought it would be. (dunno...maybe 130 to 140?)

My point is: if you have a cooling problem, and steaming/boiling...I'd suspect your exhaust water would be pretty hot...too hot to touch.

Would a damaged impeller cause more steam?

Many weaknesses in the cooling system can cause the water to discharge abnormally hot....promoting steam.

I'm still a bit surprised about your steam when you have a 16 degree spread between dew point and dry bulb.

[bkey79]

My 96 with a GT40 steams more than that! Boat usually runs around 150, water temp 87, Air temp near 100 and dew points in the 50's...

[brananders]

From reading several forums, people say that its common for Nautiques to blow a puff of steam when you hit it. But it seems that this is not universal so I'm still not sure if my boat is operating normally or if there is a problem I need to have fixed. Bkey, has your boat always done this and do you think its normal?

[TRBenj]

Steam is normal. Unless your engine is overheating, dont give it second thought. You will get more when the air and/or water temps drop (spring, fall, mornings, etc).

[brananders]

Thanks. The boat got its 25 hr service today and they could not find anything wrong. I'll quit worrying and enjoy myself.

[pmgIA]

This is fog coming out of your boat, but it has little to do with the outside air temp and water temp of the the lake, but more to do with what comes out of the boat, this is why it dissipates so quickly.

From NOAA -The dewpoint temperature is the temperature at which the air can now longer hold all of its water vapor, and some of the water vapor must condense into liquid water. At 100% relative humidity, the dewpoint temperature and real temperature are the same, and clouds or fog can begin to form. While relative humidity is a relative measure of how humid it is, the dewpoint temperature is an absolute measure of how much water vapor is in the air (how humid it is). In very warm, humid conditions, the dewpoint temperature can reach 75 to 77 degrees F, but rarely exceeds 80 degrees.
Interesting facts:
SOUPY AIR: When the dewpoint approaches 75 degrees F, most people can "feel" the thickness of the air as they breathe, since the water vapor content is so high (about 20 grams of water vapor per kilogram of dry air, or 2% of the air's mass).

[toyota40runner]

if you are tired of looking at the steam like i was then get a fresh air exhaust. steam used to billow out of my 01 san and now there is none after putting on the fresh air exhaust.

as far as the relative humidity stuff goes im pretty sure it doesnt have as much to do with the outside air RH and DP as much as it does with the air coming out of your motor. the 190 degree air with a really high RH coming out of your motor will definitely hit its dew point when it meets the outside air unless it is really hot outside. i could be wrong about this