Excessive steam/Vapour?

[Russ the Diver]

I have twin Volvo D1 20 on my cat.
Starboard engine runs fine, pumps water out of the correct outlets etc, with little steam/vapour
Port engine does exactly the same but with just a litle too much steam/ vapour.
Both engines are not overheating,, no warning sounds etc.
Can someone give me an idea where I need to be looking if I need to be looking at all/
Ta in advance
Russ

 

[Yngmar]

Probably clogged tubes in the heat exchanger insert. That's the bit that looks like a gatling gun barrel: https://www.marinepartseurope.com/en/volvo-penta-explodedview-7746500-26-9709.aspx

Buy a set of new seals/o-rings, a pipe cleaning brush and some citric acid (the red Ecover descaler works wonderfully). Pop it out, remove the debris with the brush (this is where missing impeller blades often end up) and if there's any buildup, apply some acid and scrub it off (don't leave it on for hours though). Rinse with plenty of fresh water, pop back in, new seals/o-rings on, refill coolant, engine should be happy now. Good luck!

 

[Russ the Diver]

Thanks for the reply, thought it might be exchanger. Thanks for confirming much appreciated

 

[Ripster]

Thanks for the reply, thought it might be exchanger. Thanks for confirming much appreciated

Yep, that is what I would check too if your impeller is OK and your raw water filter isn't clogged up. The other thing you could do is to reverse flush the inlet pipe to make sure nothing is clogging there either. I recently serviced the HE unit as part of routine maintenance and was shocked to find it 20-25% blocked up - no symptoms or anything from the engine.

 

[VicS]

Thanks for the reply, thought it might be exchanger. Thanks for confirming much appreciated

Any thing that restricts the water flow could be the cause. From inlet and strainer, hoses, partially blocked heat exchanger to injection point into the exhaust. As well of course a defective/worn water pump

 

[Russ the Diver]

Quick update guys. Thanks as usual for the advice.
The problem was in fact the Heat exchanger. Took it all apart and cleaned through.
Reassembled and tested. All now working as it should. Once thank you all for taking the time to post replies.
Russ