Cleaning heat exchanger

cseltzjr · **Joined:** 16 May 2009 08:06 **Posts:** 254

The factory oil cooler plumbing makes thorough routine maintenance pretty difficult. It could be that someone did the rerouting for that reason. It does make the oil cooler a bit less effective but much less prone to failure (no need for a zinc either). I can’t comment intelligently on the issues of restricted coolant flow due to the small opening in the oil cooler but the raw water is restricted the same way.

Velera · **Joined:** 29 Dec 2006 09:38 **Posts:** 656

I always felt the Westerbeke 50 oil cooler was an exceptional weakness in a cobbled together cooling system, but I do not think that rerouting the flow is the answer. Seems like a recipe for overheating. We run these engines—generally designed for taxicabs, tractors and other open applications—in very confined spaces where they have concentrated ambient heat and very little way to get rid of it—compared to their designed environment. Running a loop from the already hot engine seems absurd to me in this application.
I always felt that that W50 oil cooler was much too small to dissipate the heat it experienced and that is why it filled with salt so often and sometimes plugged so badly that it could not be cleaned. It did not require much attention to zincs—-compared with the main heat exchanger zinc which seemed to require regular attention and replacement. If I was still using a W50 I would consider replacing the expensive W50 oil cooler with a much larger generic —and probably cheaper—version (they are common and available and would seem easy to substitute) but keep the cooling side in the sea water side of the system. I realize other engines, like my Yanmar, have routed freshwater coolant for the oil coolers in them (this may be where the previous mechanic got the idea) but their cooling systems are of a completely different design for marine application.
As I have said repeatedly, the bugaboo of these small diesels converted to marine applications is the cooling system. The designers are combining dissimilar metals, very hot coolant, against very cold salt water and it is an ideal situation to generate corrosion and salt accumulation in any part of the system and you have a complicated and serious problem to solve. Also, it is “out of sight, out of mind” to the boat owner and a major PIA to properly access and maintain. Once I learned to take the system apart periodically for inspection and cleaning, I really had no problems with my old W50. Until I left it in a jungle marina for a rainy season without running it, but that was no one’s fault except mine.
Good luck with your pursuit. Seems like you are on the right track to manage this situation.
Ray Durkee

felizcortez · **Joined:** 25 Apr 2016 10:25 **Posts:** 185

I made it to La Paz yesterday and will post a picture up of the current routing of the cooling system shortly.

I spoke with a mechanic, they are at least 2 weeks out until they can look at anything. They did mention that most people remove the heat exchanger and then soak it in a bath of muriatic acid and water in a bucket to remove the build up. They mentioned that is what they would do if they did the work. This was also the answer I got on a cruisers net this morning. I'm still asking around if there is a radiator shop or something similar in the area.

I am going to try to find exhaust/hot water hose to plumb the oil cooler back into the raw water system. If I'm going to flush\clean the main heat exchanger I'm assuming I should also do the oil cooler as well.

If I can't find the hose necessary to plumb in the oil cooler, it sounds like some people have removed it completely from the system? This may be a good way to check whether the oil cooler is causing over heating in my set up.

felizcortez · **Joined:** 25 Apr 2016 10:25 **Posts:** 185

I have an engine manifold gasket, but no gaskets for the heat exchanger. Are there anything special about them or can I find some gasket material and make them? If have to order them it will be at least a week until they arrive.

felizcortez · **Joined:** 25 Apr 2016 10:25 **Posts:** 185

Another quick question. I was reading engine technical reference manual today and saw the following regarding the oil cooler.

9. ENGINE LUBE OIL COOLER:
Lubricating oil carries heat away from the engine bearings and other friction surfaces. The oil circulates from the
lube oil pump, through the engine, through the engine oil cooler, and back to the oil pump. The oil cooler may be cooled either by engine fresh water or by sea water.

felizcortez · **Joined:** 25 Apr 2016 10:25 **Posts:** 185

I was finally able to get enough internet to post a video of the plumbing. See video below.

https://youtu.be/asGEEyLi4T8

Velera · **Joined:** 29 Dec 2006 09:38 **Posts:** 656

Well, I could be wrong about questioning your hook up if the technical manual allows that—the routing is shown in the diagrams as being raw seawater as I recall. I still am skeptical based on years of servicing my much used W50 (taking apart my system) that the oil cooler is adequate for the heat generated by this engine. I think the oil cooler is probably fine for the non marine application of this engine (it was used in London taxicabs and some generators) and would, of course, use the fresh water coolant connected to the radiator. As I have said, my experience with these engines makes me very skeptical of the level of engineering and testing that was done with any of these “marinized” diesels and their seawater cooling systems.
You likely have as good marine mechanical folks in La Paz as you will encounter in Mexico or Central America. Not hard to find good mechanics and machinists in the urban areas—but recreational marine diesel experience gets hard to find. So I think you probably have access to better advice than I can give. I still would have added a bigger oil cooler had I kept my W50–regardless of whether it was cooled with sea water or coolant especially operating in the warm and tropical areas.
BTW the sea water connection between the heat exchanger and the oil cooler is a crappy part to install and I am not sure it is not on the list of no longer available parts. That may figure into your consideration if if proves to be true.
Good luck—you are lucky to be in LaPaz there is a developed cruiser community and a developing service business that is probably one of the best places to be stuck with your problem.

Velera · **Joined:** 29 Dec 2006 09:38 **Posts:** 656

Looking at the video you posted, your W50 looks different from mine. It also looks like it has been well maintained and has had attention from someone who is paying attention to maintenance of hoses and such. We started out this thread with your temps creeping up. I would suggest that you not fool with rerouting cooling lines until have assured yourself you present coolers and connections are clean (you have checked the elbow and hose out of the seawater pump for impeller fragments, no doubt) and that you still have the heat problem.
I would like to see a still picture of the front of the engine to assure myself that we are not looking at a different block than the W50. Some parts look like a 4-107 to me.
Ray Durkee

felizcortez · **Joined:** 25 Apr 2016 10:25 **Posts:** 185

I ran some barnacle buster through the system last night for a few hours and here are the results on the heat exchanger.

You can see the before in the previous posts and the after down below.

I had all the hose connections apart looking for impwller bits and also fresh water flushed backwards and nothing came out.

The barnacle buster solution did remove build up in the heat exchanger.

I ran the engine today under load at the dock to see whether this made a difference. The gauge still reads hot, but shooting the thermostat housing with a infrared thermometer it shows about 180 so now I am skeptical of the gauge and whether we have an actual overheating issue.

I bled air from the petcock/banjo fitting on top of the thermostat until coolant came out. (why there is coolant on the pad in the picture).

How can I test whether the gauge and temp sensor sender are correct.

felizcortez · **Joined:** 25 Apr 2016 10:25 **Posts:** 185

I tried to get the elbow off today but was unable to get it to budge. I need a longer pipe wrench I think. I did take the muffler off and scrapped inside what I could reach. Some stuff came out but not a huge amount. I took a picture up the exhaust hose into the elbow. See attached.

Tartan37.com

Cleaning heat exchanger

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