White steam

My 8.1HO's always have some steam. Idle, low rpm's, high rpm's. The colder the water, the more steam - or as someone above mentioned - the tighter the temp/dew point the more steam. Big temp/dew point spread, less steam. I read my temps directly from each engines ECU, zero issues.

Enjoy this....mid-December sea trial of my boat on the Ohio river. Water temp was 45 degrees. Learned all about steam from the surveyor (ya, that's him between the motors in the video) that day as I was initially taken aback...

 
My story... Had steam after a 15 minute run with the motor in my sig, no engine temp change. New mani's and elbows, now ...no steam. Hmmm
 
I've had my boat for 11yrs and replaced the manifolds just after buying. It's 8.1's have been blowing steam for the last 11yrs. No overheating ever. I was a bit concerned about it long ago, but then I noticed SeaRay's brochure for my boat had a photo of it running on the cover that clearly showed two long stream trails coming out of the exhausts. The photo was most likely taken off the shores of Merrit Island FL where the boat was made, so it apparently even steams in warmer water.

Some boats by their exhaust designs are more prone to it than others. In my case, the exhaust/cooling water from the engine is dumped into a Vernalift type can, then it travels about 6' through a 6" exhaust tube and exits out the large thru-hull ports on the stern corners.
 
scoflaw said:
My story... Had steam after a 15 minute run with the motor in my sig, no engine temp change. New mani's and elbows, now ...no steam. Hmmm
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Always nice when you dodge the bullet!
 
IMG_4230.JPG
JVM225 said:
I get that the water and ambient temps can contribute to the appearance of steam, but if it were me I would be a bit concerned that as you say it doesn’t happen at idle, but only under load.
Depending on the answers to the following questions I may want to take a little bit more of an in depth look if it were my boat.
1. Is this steam something new?
2. What does your gauge say you’re temp is when the steam appears?
3. How old are your manifolds and risers?
4. What did the old plugs you replaced a few days ago look like?
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I believe you are overthinking this issue. We have never owned a boat that did not blow steam out the exhaust, and they all did it when they were brand new out of the box.
 
E10F9664-70F0-4BE1-8648-AB55EE33270B.png
i dug this pic out , this is after two fresh motors. There have been days when I would only see a wisp of steam and other days it would be 20 foot trails like in pic above. But knowing that my water pump is good as well as my exauhst system and after a few years of knowing this I’m confident it’s Atmospheric
 
sbw1 said:
View attachment 71643
I believe you are overthinking this issue. We have never owned a boat that did not blow steam out the exhaust, and they all did it when they were brand new out of the box.
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X2. I'm in agreement with this. How much steam depends on exhaust temp, water temp, air temp and humidity. My 454 Crusaders blow steam all the time but more when the air is cold and dry. I consider it normal.
 
The difference between the Problem/No Problem guys are the No Problem guys know their boats and manifold riser history very well.

If the OP knows the condition of manifolds and risers, then probably OK. If unknown, might be worth going through the progression John posted, especially since hes in salt water.

Water ingestion is an expensive fix, and risers are a KNOWN contributor to the early demise of engines.
 
FWIW i have owned my boat for several years and operate it in all kinds of weather and both hot and cold ambient and water temps....never once noticed any steam from the exhaust....

cliff
 
dtfeld said:
The difference between the Problem/No Problem guys are the No Problem guys know their boats and manifold riser history very well.

If the OP knows the condition of manifolds and risers, then probably OK. If unknown, might be worth going through the progression John posted, especially since hes in salt water.

Water ingestion is an expensive fix, and risers are a KNOWN contributor to the early demise of engines.
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Particularly in the salt water.
If I were to purchase a boat and didn’t know, or couldn’t verify, the age of the exhaust I would factor in the cost of replacement and chalk it up to cheap insurance.
If that new to me boat exhibited
sbw1 said:
View attachment 71643
I believe you are overthinking this issue. We have never owned a boat that did not blow steam out the exhaust, and they all did it when they were brand new out of the box.
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Ahhhhh......
The difference here is that you knew what the norm was for your boats because as you say “and they all did it when they were brand new out of the box”.
Is this 19 year old boat relatively new to the OP or is it a boat that, like you, he has owned since brand new out of the box?
He has indicated though that he isn’t sure if the steam is a new thing in his 19 year old boat or something he just hasn’t noticed before.
He also hasn’t yet said how old his exhaust is, if the temp gauge is telling him anything or if there were any telltale signs on the plugs he recently removed.
But he was concerned enough about the steam to pose a question here.
Asking 4 basic clarifying questions before taking a strong position on whether or not the steam may be cause for concern could certainly be considered overthinking things a bit by some, but so might being dismissive while lacking additional information.
To each his own.
What makes this forum a great place is that a user can come here to get a bunch of information based on other people’s experience and then choose whether or not to use it.
 
CliffA said:
FWIW i have owned my boat for several years and operate it in all kinds of weather and both hot and cold ambient and water temps....never once noticed any steam from the exhaust....

cliff
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That sounds about right considering that you have an underwater exhaust set up on your boat, the boats that have above the waterline exhaust will always show condensation/steam To some degree that’s a matter of physics
 
I have no idea, either way. Here is a pic of mine, 07 350 5.7L MPI, fresh water cooled, 2016 manifolds/elbows/risers, memorial day weekend. Engine temps are solid 165-ish. You can see just a bit of steam/smoke/something.
Am I okay?
6AA7E7AB-D8AC-4A3F-A491-47AA4C84D2D2.jpeg
 
Todd320 said:
I have no idea, either way. Here is a pic of mine, 07 350 5.7L MPI, fresh water cooled, 2016 manifolds/elbows/risers, memorial day weekend. Engine temps are solid 165-ish. You can see just a bit of steam/smoke/something.
Am I okay?
View attachment 71677
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Good temps and manifolds/risers known to be only on their third season equals fun boating!
 
Great Lakes said:
I run 162-165 and I look the same.
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Temps are important.
In saltwater, the age of the manifolds/risers/elbows is important. Number one cause of catastrophic engine failure around here is hydro lock attributed to bad exhaust components.
Life expectancy for good quality OEM exhaust is about 5 years in this area. Aftermarket is more of a crap shoot.
 
dtfeld said:
The difference between the Problem/No Problem guys are the No Problem guys know their boats and manifold riser history very well.

If the OP knows the condition of manifolds and risers, then probably OK. If unknown, might be worth going through the progression John posted, especially since hes in salt water.

Water ingestion is an expensive fix, and risers are a KNOWN contributor to the early demise of engines.
Click to expand...

I agree. To make things even more confusing for me was that my 360 with 8.1's steamed from the get go and after changing manifolds.
It steamed evenly from both sides, a lot. It never was a problem.
My 400 DB steams only from the starboard. Did at sea trial and surveyor said that as long as all temps and IR gun readings are normal, it can just be the nature of the beast. I took pictures of it shortly after purchase. I thought there might be a problem because it was only one side. I was all over that exhaust system from Barnacle busting to visual inspection to IR readings everywhere. It doesn't steam as much as the 8.1's did, but the fact that the port side never steamed at all had me guessing.
Fast forward 6 years, over 2000 hrs, and completely servicing the raw water cooling twice, including new fuel coolers, new tranny coolers, new SMX water pumps, new exhaust hoses at the mixer elbows and inspection of the mixer elbows, all done because of age/hours of use/preventive maintenance over that time period, she still steams on the starboard side just like she did back then.
I just chalk it up to maybe a slight difference in the configuration of the exhaust system from one side to the other? Don't really care what the reason is because I Know it's OK.

Starboard side
DSC_0118.JPG


Port side
DSC_0119.JPG
 
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