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That STEAM thing

knuckle47

knuckle47

Advanced Contributor
"In the posts about : "Whi

"In the posts about : "Which pump is correct", I brought up the question about the steaming exhaust on my 1992 engines. In fact I may have asked this question a few months back. The explanations seem logical and make sense but I get the feeling that a 15 foot trail of steam behind the boat at 3000 rpm MIGHT NOT be considered normal. While temps are normal and it is not overheating, I should be looking for a cause if this is NOT the norm...

WHAT parts in the system might cause this. I do have new manifolds, elbows, block off, e-35 pumps, valve jobs, head gaskets...etc. Basically new from the piston tops to the exhaust holes in the transom. The only thing left from before are the heat exchangers which I am "pretty sure" are clean.

I need a push in the right direction"
 
"I assume you have an infared

"I assume you have an infared non-contact temperature gun, and that you've 'shot' the entire exhaust system end to end, to see what temps it is running at?

Hummm?? Hummmm?

Jeff

Disclaimer: Contrary to what you may have heard, I do not get a kickback on every infared non-contact temperature gun sold!"
 
"Yup!...Temp on the u-coolers

"Yup!...Temp on the u-coolers are about 96, Elbows 130, thermostat housings about 150, manifolds about 170. Of course they fluctuate a few points either way during operation but this is about average for BOTH engines.

Incase it means anything, the air out of the s/c vent at the dock is 44 and my left hand about 87 right hand 86....I have had that gun read temps of almost anything I can point it at!"
 
"Including the cat! (About

"Including the cat! (About 95 degrees.)


That sounds about right for IDLE conditions, but have you taken temps at cruising speed? That's different.

Jeff"
 
I had a similar steam problem

I had a similar steam problem and it turned out to be the water pump that is on the engine fairly expensive but fixed the problem fine.
 
"Funny, Yesterday, lower humid

"Funny, Yesterday, lower humidity in the atmosphere and the steam trail was bout 2 foot long.

Derrick, You mean the antifreeze pump or raw water pump?"
 
"Al:

is it steam or is it c

"Al:

is it steam or is it condensation?

Jeff's use of the temp gun is a great idea. I'd suggest looking for a difference between your exhaust segments as an indicator.

The only time i get 'steam' is when there isn't enough water - usually the impeller is worn or the oil cooler is clogged.

Shoot the gun at the exhaust outlets and see what it is there - if there's no temp difference but one is clear and the other 'steams', I'd say look for a restriction at one of the risers. If a piece of flashing was there and it popped free once you ran her, that could do it. you should be able to see it in the temps at the exhaust hoses, about a foot or two 'downstream' of the riser outlets.

If both sides 'match' but only one 'steams', something is different between the way the plumbing runs from the risers to the transom. If you can't find a hot spot and both engine temps are 'close', i'd say it isn't worth worrying about anymore."
 
"Thanks for the confirmation M

"Thanks for the confirmation Mark...Saturday, practically Zero steam, maybe a 2 foot tumbling trail at 3200 or so. Below these rpm's usually nothing. I will re-measure everything this weekend and see where it gets me."
 
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