Visit our Popular Forums

**skipmac** · 11-05-2019, 08:52

Just spoke with a friend that suggested it could be a leak in the water cooler between the fresh and raw water. That seems to be a possibility but how would one test for that? If I pressurize the fresh water cooling system it could show a leak but not where it's leaking.

Jason Flare · 11-05-2019, 08:52

I wonder if you could put some dye in the coolant and see if it’s exhausted out?

Valmika · 11-05-2019, 08:56

I hate to break it to you but this same issue baffled me on my Westerbeke 42B (mitsubusi block) for a long time. Eventully the leak became faster. I couldn't figure out where the coolant was going. I took of the HE and pressure tested it. (you can do this with your mouth) It seemed fine. Cleaned and new gasket and put back. The checking for bubbles in your tank was my first clue. Second we did a pressure test on the cooling system (standard radiator leak test kit) Pressure in the cooling system shot up to over 90 PSI. They should normally run at about 15 PSI. This means gasses from you cylinder are escaping into your cooling system (through a crack in your head or your head gasket)

Now the fun part:

Source the parts and see what they will cost before deciding to move forward

I removed the head myself. Take lots of pictures so you know where everything was. Wires, hoses fuel lines, Everything!! Careful with the fuellpump if you have to remove it. You don't want to mess up the timing.
If you don't have to remove it to get to the head, DONT!

I figured while I had it out I would rebuild and resurface the head and lapp the valves and rebuild the injectors. Near me in Los Angeles there was a commercial truck engine repair place that did my head for $450 and the injectors (4) for about $300

BTW They also did the fuel pump for about $350 (see don't mess up the fuel pump timing)

I was told I should replace the head bolts as they stretch ($80 apiece times 12 or something like that) I politely declined.
I did hire a great but busy mechanic to help me put it back together and get it set up $1000. It has been fine for over a year now so I guess I did OK. I don't want to get too far ahead so do your checks and I will help you more if I am able.

sainted · 11-05-2019, 08:56

As Tek suggests, a likely culprit is your heat exchanger, which is leaking fresh water into the raw water side.

To test, disconnect the raw water hoses, fill the fresh water system and pressurize the fresh water system with a pressure tester (Available at your local auto parts store. They may even loan you one). If coolant comes out of the raw water connections on the heat exchanger, you've got a leak.

A radiator shop may be able to repair it, but I'd be inclined to replace it if it's very old.

**skipmac** · 11-05-2019, 09:01

Quote:

Originally Posted by skipmac

Just spoke with a friend that suggested it could be a leak in the water cooler between the fresh and raw water. That seems to be a possibility but how would one test for that? If I pressurize the fresh water cooling system it could show a leak but not where it's leaking.

Guess I would have to pull the heat exchanger off and pressure test it off the engine?

Valmika · 11-05-2019, 09:01

Quote:

Originally Posted by sainted

As Tek suggests, a likely culprit is your heat exchanger, which is leaking fresh water into the raw water side.

To test, disconnect the raw water hoses, full the fresh water system and pressurize the fresh water system with a pressure tester (Available at your local auto parts site. They may even loan you one). If coolant comes out of the raw water connections on the heat exchanger, you've got a leak.

A radiator shop may be able to repair it, but I'd be inclined to replace it if it's very old.

If you are in the Galapagos I wonder if you could test HE in place by using your fresh water pressure system on the coolant side of your HE to test. (about 40 psi) Leave the raw water side open and se if you have a leak

I did get a new HE from a website called MR Heat ex changer or something for about 1/3 the price of the Westerbeke one) HE was my first thought also because your coolant is at about 15 PSI but your raw water is not pressurized. Unfortunately in my case this wasn't the issue

Valmika · 11-05-2019, 09:03

Here it is:

https://www.mrcool.us/35135-westerbe...SABEgK1lPD_BwE

**skipmac** · 11-05-2019, 09:05

Quote:

Originally Posted by Valmika

Here it is:

https://www.mrcool.us/35135-westerbe...SABEgK1lPD_BwE

Good company to deal with. I bought a new oil cooler from him.

**skipmac** · 11-05-2019, 09:25

The more I think about it the more I think it could be the heat exchanger.

1. No water in the oil.
2. No oil in the fresh water system.
3. No steam or leaks visible.

Teknishn · 11-05-2019, 09:29

As has been suggested to test the heat exchanger: pressure testing or adding dye. A cheap and easy test since you stated that you lost nearly a quart of fluid at one point (which sounds like a large loss to me) is to mix up a couple of quarts of red Kool-Aid (without the sugar), add it to your coolant, run the engine for a bit and watch your heat exchanger overboard discharge for any red discharge. If no red discharge, then I would proceed with considering pressure testing of the entire coolant system.

Cheechako · 11-05-2019, 09:34

It might be a head gasket, they can either get water in the cylinder that burns off or get it in an oil passage and in the oil. Or both.
You could also have a heat exchanger leak, and there may be a transmission cooler/exchanger also.
Removing the head is not a huge deal and, depending on room to work, you may have it off in less than an hour. You can carefully study the visible traces on the block, head and gasket to see if a leak is obvious.

Valmika · 11-05-2019, 10:08

Quote:

Originally Posted by skipmac

The more I think about it the more I think it could be the heat exchanger.

1. No water in the oil.
2. No oil in the fresh water system.
3. No steam or leaks visible.

Just curious, where is the boat right now? Maybe someones knows of a facility close by.

slowpoker · 11-05-2019, 10:22

After testing the cooling system and before taking the head off, if you still cannot find the problem using all the very good suggestions made by all here, you could do a compression test of each cylinder by using an old, hollowed out injector without the internals of it, or make up some fitting to fit where the injectors go and with a diesel injector tester from one of the discount tool places, check each cylinder piston and valves, wet and dry cranking before removing anything else. Otherwise removing the head will lead you to replacing head gasket, bolts, lapping valves and on and on. Hoping its just a leaking hose but you mentioned harder cranking and temperatures rising. Good Luck with this.

model 10 · 11-05-2019, 10:56

It's unlikely that you would get water in the oil from just a blown head gasket. The water passages in the block and head are right next to the gasket sealing ring around the cylinders. The only opening in the bock leading to the oil sump is on the other side of the block from the piston. There is not really any reason the head gasket would leak that way, on this engine anyway.