overheating and leaking heat exchanger

Steph

.
Sep 30, 2005
52
Cal 28-2 Port Annapolis, Annapolis, Md
After process of elimination to find the cause of my overheating engine, Westerbeke 13, (210 - 225 degrees), my heat exchanger has an internal leak! I brought it home to rinse out with vinegar and confirmed (with food coloring) that the raw water side is leaking from the "thin tubes" with the anti-freeze side. Can this explain the overheating? Interestingly, my antifreeze levels were never low. I assume the antifreeze side has higher pressures than the raw water side but levels didn't drop. Can this be repaired or is it time for a new heat exchanger? Should I look for another cause for the overheating? Thanks!
 
Nov 6, 2006
10,088
Hunter 34 Mandeville Louisiana
Yes, the overheat can (not sure it is actually, in this case) be caused by the leaky tubes. The coolant side will not be able to hold pressure and there can be some local boiling, especially in the cylinder head that will affect the flow and cause overheating.. Like operating a car with no radiator cap. When the engine stops, the coolant side will then pull raw water back into the fresh water side so you won't see a drop in fluid level.. While the bundle is out getting repaired/re-tubed, check the elbow and water pump and strainer for proper function.. Good luck..
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Steph,

You don't have to buy from Westerbeke. There are a number of aftermarket manufacturers of heat exchangers to fit the Westerbeke.

Try Lenco Coolers in NY. They used to be a supplier to Westerbeke and now supply replacement HX's for both Westerbeke & Universal. What Kloudie said about the pressure can lead to an overheat.
 

Steph

.
Sep 30, 2005
52
Cal 28-2 Port Annapolis, Annapolis, Md
thanks

makes sense that it would leak antifreeze into the raw water when hot then suck back in raw water when cooling... makes sense! Didn't think of that. Appreciate your help. Steph
 

Steph

.
Sep 30, 2005
52
Cal 28-2 Port Annapolis, Annapolis, Md
temp holding

Thanks again. I cleaned out the HX and re-installed. Not sure what I did right but now it's holding at 175-180 degrees. We'll see if it lasts. thanks all. Steph
 

Steph

.
Sep 30, 2005
52
Cal 28-2 Port Annapolis, Annapolis, Md
thanks for all the advise... cleaned it out and re installed and temp is holding at 175-180! By the way, Lenco had a new HX for $295. Thanks. Steph
 
Nov 6, 2006
10,088
Hunter 34 Mandeville Louisiana
Great news.. Good to have a new set of tubes in there that should serve for a long time..
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
thanks for all the advise... cleaned it out and re installed and temp is holding at 175-180! By the way, Lenco had a new HX for $295. Thanks. Steph
Good news! How did you solve the leak?