Running Hot

Steph Lakner of Annapolis, Maryland, asks:"I have a Westerbeke engine (circa 1987) on a Cal 28. The engine overheats (to 210-215 F) after about 20 minutes running at full rpm. The impeller is fine, but water flow is reduced beyond the heat exchanger. I have found no obstructions (broken vanes, etc). I brought the heat exchanger home and cleaned it with vinegar. It was
Author:
Publish date:
Updated on

Steph Lakner of Annapolis, Maryland, asks:

"I have a Westerbeke engine (circa 1987) on a Cal 28. The engine overheats (to 210-215 F) after about 20 minutes running at full rpm. The impeller is fine, but water flow is reduced beyond the heat exchanger. I have found no obstructions (broken vanes, etc). I brought the heat exchanger home and cleaned it with vinegar. It was already pretty clean, but I found leaks in the “little tubes,” so raw water has been mixing with the antifreeze. Interestingly, the antifreeze level is always normal. Should I try to repair the heat exchanger or should I replace it? Could this be the cause of the overheating, or I should look elsewhere?"

Nigel Calder replies:

If raw-water flow is reduced, this most likely is the cause of your problem. Although you have replaced the pump impeller, the pump housing may be worn, and this can also cause a loss of output. If this is not the case, another place water flow can be obstructed is at the injection nipple into the exhaust system. You should also check the feed to the water pump to make sure the hose is not kinked or collapsed. Sometimes the hose gets soft with age and then collapses due to the suction pressure from the pump.

One way or another, you want to get the raw-water flow back to normal. You also need to replace the heat exchanger. If salt water is mixing with the fresh water, the salt will scale up your engine, which can itself lead to overheating. Descaling the engine will certainly be more work than sorting out obstructions in the raw water flow.

Lastly, is the hull seriously fouled or might there be something wrapped around your propeller? This would increase the load on the engine and could also cause it to overheat.

Related

Pestilence

Sailor-Punk and the State of Cruising

Back when I was a young man, sailing back and forth across the North Atlantic in an old fiberglass sailboat, it seemed fairly obvious to me how all that was wrong in the world might be set right. Everyone should be issued a boat at birth! Or so I declared to any who would listen ...read more

promoOnTheHorizon600x

Cats On The Horizon

Dragonfly 32 Evolution Denmark’s Quorning Boats has been systematically upgrading its line of folding, performance-cruiser trimarans in recent years as part of a long-term effort to incorporate the latest developments in yacht design, with the latest to receive this treatment ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell. Got a tip? Send it to sailmail@sailmagazine.com The double range  Every skipper knows about ranging two objects in line to keep the boat on track in a cross-current. What’s less obvious is monitoring both sides of a gap such as a harbor entrance. ...read more

FamilyCruise

Bareboating on Puget Sound

Depending on where you are, Puget Sound can look no bigger than a mountainous version of the Intracoastal Waterway. That’s what I thought when I first laid eyes on it from the lighthouse at Mukilteo Park on a sunny day last July. Then I went to the top of the iconic Space Needle ...read more

Bali4point1

Boat Review: Bali 4.1

Coming fast on the heels of its predecessor, the Bali 4.0, the Bali 4.1 adds a number of improvements, many of them inspired by feedback from owners and charterers. She’s an evolution of a concept that has already proven popular and very many benefits from its builder’s ...read more

Headsail

Ask Sail: Silencing A Rattling Headsail

Q: Our Pearson 26 has a 110-percent jib that tends to rattle very noisily at the top hank. We only bought the old boat recently, but it must have been happening for a long time, since there’s a deep groove worn inside that bronze hank. The jib has an unusually large and wide ...read more

Alerion2048x

Alerion Yachts 33, the 90 Minute Get Away

Easy to sail, luxurious, and swift; the Alerion 33 is the solution to your busy life. The intuitive, simple rig design, easy set-up, and put-away mean there’s no need to wait for crew to enjoy a weekend, a day, or an hour out sailing. Her beauty and comfort are evident in the ...read more