Westerbeke 27 overheating troubleshoot

[Russian007]

UPDATE:The tubing isn't removable and the acid bath didn't do anything to loosen up the closed tubes. Looks like I'm headed to the radiator shop.

[Russian007]

UPDATE: local radiator shops don't deal with heat exchanges because of EPA regs.

[Diesel Bill]

Go to Home Depot and buy a 1/8 inch BRASS brazing rod. Pull end cover off of heat exchanger and push BRASS rod through the cooler tubes. Do each tube several times so to make sure you get them all. Most tubes will be plugged with calcium carbonate scale. Sometimes it's soft and sometimes hard like cement. Be patient and punch tubes all the way through. Sometimes you can't go all the way through on the first pass. My engines ran hot when I bought my boat. 230 degs. After rodding the coolers they now run at 175-180.

[Russian007]

Originally Posted by Diesel Bill

Go to Home Depot and buy a 1/8 inch BRASS brazing rod. Pull end cover off of heat exchanger and push BRASS rod through the cooler tubes. Do each tube several times so to make sure you get them all. Most tubes will be plugged with calcium carbonate scale. Sometimes it's soft and sometimes hard like cement. Be patient and punch tubes all the way through. Sometimes you can't go all the way through on the first pass. My engines ran hot when I bought my boat. 230 degs. After rodding the coolers they now run at 175-180.

Thanks but I threw in the towel and took the HX to a radiator shop. What I thought was a calcified tube turned out to be a old solder repair to fix a leak. That's what the radiator guy said. He's gonna soak it, and pressure test it and I'll assess from that point.

[Russian007]

UPDATE: still having overheating issues. New water pump and thermostat and HX flush at radiator shop in last year. Ran the motor for 15 minutes NOT under load and this happened:

https://www.youtube.com/watch?v=tNkX...m-upload_owner

after shutting down it gurgled into the overflow

https://www.youtube.com/watch?v=TLnjS5hwDyg

[Mutt]

Picture one looks like thermostat gasket is leaking. Is the thermostat in the right way around?

[Russian007]

Originally Posted by Mutt

Picture one looks like thermostat gasket is leaking. Is the thermostat in the right way around?

It is indeed leaking. I will take it off and send pics. Seemed like there was only one way it could fit....

[Mutt]

Often times thermostats can be installed upside down. Ensure that the copper button is pointing down. Also leaks prevent the proper pressure build up and may allow over heating and coolant to boil at too low a temperature. It is normal for the coolant level in the reservoir to go up when the coolant gets warm and expands. Bottle should only be half full when cold. Both an upside down thermostat and a leak can cause the coolant to overheat and boil.

I hope this helps. Good luck.

[a64pilot]

You sure it's overheating? The overflow tank seems overfilled, did it start out overfilled?
I ask as it looks a lot like a blown head gasket. Gases get pushed into the coolant, which causes that tank to overflow, and the bubbling isn't boiling coolant, its air.

[Russian007]

It over heated. Temp gauge was headed toward 220 when I shut it down. It was really hot. Overflow tank started out empty.

[CS Cruiser]

Were you sure to purge all Air out of system?

[jimbunyard]

Well you know what you've changed and cleaned, so that rules out those items.

Given that the water on the freshwater side is dirty, I'm guessing that you have an internal blockage somewhere (provided that there is no airlock).

The solution would be to start disassembling things, easiest first, until you find the problem, though a better plan might be to assume the worse and disassemble the whole cooling system (exhaust manifold, heat exchanger, circulation pump, t'stat housing...the whole nine yards) to ensure you have all the bases covered.

If you want to go at it piecemeal, I might have a look at something called the 'flo-controller' that is bolted to the aft end of the exhaust manifold. The service manual (available here https://www.westerbeke.com/Category/...BF61A#techdocs
) is strangely silent about it, but it is listed in the parts manual (https://www.westerbeke.com/Category/...BF61A#techdocs).

I don't actually know what it does, but from the description in the parts manual, and its' name, it looks like it somehow controls the flow of fresh water to the heat exchanger.

[Russian007]

UPDATE Was at the boat today. Fired her up, pulled off the coolant cap and didn't see any bubbles. Pulled dipstick, no pressure or oil being sprayed out so hopefully head gasket is okay. Same spot by thermostat still sprays out a little water as shown in the video. Tomorrow I'll try tightening the bolts around the thermo, add water and fire her up and see if she still overheats. and yes I will bleed out the air.