lots of steam

[colhel]

I took the boat out on Saturday for a bit of a run after re-fitting the heat exchanger.
I'm not sure if the amount of steam coming from the exhaust (quite a lot) is normal bearing in mind the ambient temperature. I'm going to change the impellor and check the strainer as a matter of course and anything else within easy reach, but with temperature gauge not going above 90deg even WOT how concerned should I be? I'm aware the question "why's my exhaust steamy" is a bit like how long's a piece of string, but....

Cheers

 

[BruceK]

I found mine to show more steam early season when the water is still cold and the spring air saturated. Whether or not you have a fault is another matter. Did you get a chance to look at any other boats out and if so did they not show the same?

 

[jrudge]

What engines ? 90 is pretty hot. Volvos run in the low 80s

When you say Re fitted have you de calcified it ?

 

[colhel]

Its a tamd41a, I filled it with brick cleaner to try and fizz it out.
There weren't any other boats out, wasn't a very nice day really.

 

[jrudge]

Props and bum clean ?

The impact on temps and fuel. Insulation when dirty is astonishing. I burned another 250 LG’s on a trip to Ibiza last year as a result.

 

[Greg2]

What engines ? 90 is pretty hot. Volvos run in the low 80s

When you say Re fitted have you de calcified it ?

If I recall correctly 90 was within range on a boat we had with KAD42s and they used to run at around that. Last boat had Perkins and ran at 80-85, which was notably lower.

 

[jrudge]

The thermostat temp is 82 degrees.

 

[andy59]

Colin, when you did the work did you check the exhaust elbow on the turbo as they can get restricted with rust/ debris.

 

[Mike k]

another thing to do is to check your manual and it will tell you how much water should be expelled at different revs, any less and its a restriction somewhere. I had this and it was a coating of fine gunge on the seawater strainer basket that wasn't really visible until removed and washed. Furthermore if it was 'lots of steam' as you quote that could be a placcy bag or something blocking part of your inlet scoop

 

[colhel]

Andy, I haven't checked the exhaust elbow, but will.
jrudge, She was antifouled last August but since November has been kept in Weymouth Marina quite close to sluse gate which when opened allows fresh water in, so even though the hull looks clean there could be tube worm on the shaft and prop which is difficult to check.
Thanks Mike, I'll check the strainer again and the inlet scoop.

Cheers

 

[kashurst]

good call on the exhaust elbow too. worth taking it off and have a look at the stainless insert next to the turbo for pin holes.
check the temperature of the thermostat housing with an IR thermometer too. My temp gauges over read by @ 6 degrees.

 

[jrudge]

Andy, I haven't checked the exhaust elbow, but will.
jrudge, She was antifouled last August but since November has been kept in Weymouth Marina quite close to sluse gate which when opened allows fresh water in, so even though the hull looks clean there could be tube worm on the shaft and prop which is difficult to check.
Thanks Mike, I'll check the strainer again and the inlet scoop.

Cheers

Had I not experienced it myself I would not have believed the difference. It was the first trip of the season and off we go to Ibiza. Temps pretty high. Full consumption Hi. Boat speed - low.

Scrape the props off and had as much of a go on the bottom as a tank of air would let me. Transformed.

Well aware you will slow down, aware you will use more fuel ( but not as much as I actually did). Didn't know temps would rocket. I do now.

 

[DavidJ]

Colin, when you did the work did you check the exhaust elbow on the turbo as they can get restricted with rust/ debris.

Hmmm interesting!
I replaced both turbos last year but didn’t touch the elbows. They obviously weren’t blocked but had interior rust. Is this a really important performance factor?

 

[andy59]

This is what I found when I checked our old boats turbos, an easy clean and improved water flow and reduced steam .

 

[colhel]

Thanks all. Plenty to keep me busy. Cheers

 

[Dazzajohm]

Are you on outdrives? I had an issue with steam on my last boat and it turned out to be a burst exhaust bellow. It was replaced and the same thing happened again. Turned out the engineer I was using at the time was using non Volvo parts and it just wasn’t up to the job. Got the proper VP part and no problems after.

 

[Mr Googler]

View attachment 76216
This is what I found when I checked our old boats turbos, an easy clean and improved water flow and reduced steam .

That’s nothing....

Before

New

 

[colhel]

Ours is shaft drive. Looking at the schematic for the tamd41 A, I'm slightly reluctant to start taking the exhaust elbow off until due to the exhaust flap, I haven't had a good prod around yet but I'd be worried about damaging something. It's a very restricted working area too which doesn't help.