Heat exchanger zinc

[clp]

11 years..

Wow, eleven years of neglect. I could not have that kind of luck. I turn my back on an engine for a second, and the crank will unscrew out the back.
But this many years of inattention would concern me. The debate over the thermostat would not even be a consideration. Change the silly thing. A ten dollar part like that could leave you somewhere. Like in the channel, with a freighter bearing down is where it would happen to me. The ts may be generic, and a gasket cut out of a Coke carton. Or beer if it comes to that, but use a Michelob carton, not Bud. Show some class here, we are after all yacht owners. And I've made gaskets like this countless times, they work well.
One other thing I've not seen touched on here yet.You know you are doing the right thing getting rid of the rotten HE, and hoses, (the 11 year thing), and yes, it probably needs burping. But 140 degrees? Unless there is something VERY specific about a Universal, (and I doubt it), but that is too cool. In fact, it's a slow murder. Short of a two chapter book about burning up the "acids" in the oil, poor combustion is the operative term. Short of an overheating issue, and the obvious no-brainers about running it out of oil, that is a terrible thing. 180, or 190, even 195 is the norm. A hot diesel, is a happy diesel.

 

[Loren Beach]

I believe that the stock termostat for the M25XP is 165 deg.
That's what ours does.

Loren

 

[clp]

Hmm. I'm corrected. But I'll buy that. It's still better than 140. If there's pale smoke coming out the pipe, it shouldn't. A properly "tuned" diesel ideally should not smoke at all. Now, that said, I've built high horsepower diesels, that when standing in the throttle, would POUR black smoke out the pipe, but that's not to say it was efficient. It just sounded like from the "symptoms", that it could be warmed up a little. Not that I'm recommending this, but I've seen some even run over 212 degrees, but these were generally semi worn out engines, that needed the heat to complete the combustion process.
However, we're not building tug boats here.
So, obviously that's a little extreme. But when a diesel gets a few miles under her belt, sometimes a little more heat ain't bad.

And I'd be willing to bet, that in eleven years, (with the same impeller albeit), that those valves haven't been adjusted either. There again, I could be wrong, not knowing the engine SPECIFICALLY, but most small diesels I've been close to, have solid lifters, and should be gapped regularly. I don't think I need to say why. But, it could be another symptom of the smoke "issue". And it is one of the few things that should be done to maintain an inherently very simple engine.

 

[our38]

Overheating resolved

Just start the engine and loosen the plug; once the engine is running and the coolant is circulating I don't think the engine has to be up to temp. Marine Diesel Direct (Toressen Marine) should have t-stat and gasket; MDD is pricey however, so it is worth searching for other sources; I found TDC Equipment in Huntington Beach, relatively close to me, to be better. If you can cross reference the t-stat part number or engine block to the Kubota tractor model, a tractor supply store might have even better pricing. Someone around here put together a cross reference list at one time. MDD has manuals for the Universal engines I believe. I usually look up part numbers on their website and try to find better deals elsewhere.

Mark, thanks. I loosened the plug and bled the air out, and that seemed to work. I let the engine run for 30-40 minutes, in forward, at around 800-900 rpms. I think the temperature got to around 150. I'll start it again early tomorrow and let it run for another 45 minutes or so, then I'll take it out and run it up to 2200 rpms to see how hot it gets.

I'll have to read up on tune ups and valve adjustments, since I'm fairly sure that hasn't happened in 11 years. I'll keep an eye out for leaks, and i'm carrying extra replacement hoses, a container to hold any coolant I might have to drain AND extra coolant.

 

[mherrcat]

Glad that worked for you. As far as a $10 thermostat, let me know where to find that; Torresen wants $38 for the 5432 t-stat. They want $60 for the M25XP t-stat.

 

[clp]

Oh Lerd...yeah, what was I thinkin'. I really should have known better. Every time I need something from them, I have to mortgage the farm. 200 dollars for a silly little 3 hole head gasket, geez.
I should have gone into the marine parts business..

 

[our38]

HX and Temperature

I replaced ALL the hoses below the waterline on my E38 when I purchased her. Not knowing the vintage and many were visibly dry rotted, etc. it was the prudent thing to do. Any hose connected to a seacock or critical fluid like coolant, etc. is a candidate for close inspection and replacement. I cannot comment on the grease cup, I have the Sherwood pump and it doesn't have one. There are many folks here with the Oberdorfer, they will have the answer.

RT

Rob, since your E38-Ruby is close in age to our E38-Forever Young, and since you have changed your HX and hoses (although you have a different water pump), what temperature does your engine run at once it's warmed up? Have you also changed your thermostat? September, October, and maybe November, are good sailing months here, so I don't plan on doing any unnecessary work on our E38 until after that time. The thermostat seems like a good candidate for change, especially if the engine is running too cool (not sure why that matters yet, but I'll understand at some point).

 

[our38]

HX and Temperature

Hmm. I'm corrected. But I'll buy that. It's still better than 140. If there's pale smoke coming out the pipe, it shouldn't. A properly "tuned" diesel ideally should not smoke at all. Now, that said, I've built high horsepower diesels, that when standing in the throttle, would POUR black smoke out the pipe, but that's not to say it was efficient. It just sounded like from the "symptoms", that it could be warmed up a little. Not that I'm recommending this, but I've seen some even run over 212 degrees, but these were generally semi worn out engines, that needed the heat to complete the combustion process.
However, we're not building tug boats here.
So, obviously that's a little extreme. But when a diesel gets a few miles under her belt, sometimes a little more heat ain't bad.

And I'd be willing to bet, that in eleven years, (with the same impeller albeit), that those valves haven't been adjusted either. There again, I could be wrong, not knowing the engine SPECIFICALLY, but most small diesels I've been close to, have solid lifters, and should be gapped regularly. I don't think I need to say why. But, it could be another symptom of the smoke "issue". And it is one of the few things that should be done to maintain an inherently very simple engine.

Clp, once I'm able to run the engine for awhile I'll be able to determine the temperature at which it really runs. I'm a recently new (first time) sailboat owner (or boat of any type), with absolutely no diesel engine experience; I have way more questions than answers. Although our E38-Forever Young, is 32 years old, and wasn't taken out of her slip in about 11 years, my understanding from the PO (also the original owner), is that the engine was started every couple weeks or so AND was put in forward, or reverse, to run for a little bit (don't know how long). The hour meter for the engine shows 630 hours, and I believe those to be original hours; so I believe the engine just needs some TLC, proper care, and maintenance. With that said, I don't think she is that old really, and I just need to learn how to change a plug, adjust a valve, and do all the other things sailboat owners love to do besides actually going sailing. If you happen to have a 5432 repair manual laying around (that you don't need), or a link to where I can get one, please let me know.

 

[rwthomas1]

our38,
Yes I replaced the the thermostat. My engine runs at 160*F no matter what. That was not the case when I got the boat.

-Do you have a waterheater on your boat and is it plumbed into the engine coolant circuit? Why do I ask? Well I found that the waterheater coolant circuit was restrictive and slows the coolant flow enough that the engine would overheat if operated for any length of time over 1800rpm. The pic of your thermostat shows a short/small hose running from the top of the coolant pump to the thermostat housing. That is the bypass hose and if you hook the waterheater up to those nipples the engine will NEVER starve for coolant flow. This was the main thing that kept my engine from running cool. Its an easy mod, just use standard 1/2" automotive heater hose, change the barbs on the waterheater to match. Prime the coolant circuit during installation so there is no significant air trapped.

-Replacing the thermostat is as easy at the 57 Chevy you used to work on....

Hope that helps, RT

 

[clp]

38, I just thought I read earlier where the engine was running 140, maybe 150 degrees. Too cool for fuel burner.

And Mr. Thomas said it right. If you can change a thermostat on the Chevy, this one will be a whiz-bang for you.

And do not let the diesel "intimidate" you. One of the many reasons that I like diesels are their simplicity. I think a lot of people are skittish about them because they did not grow up with them in their first cars. If you can work on a horrible gas burner, the diesel will be a pleasure. I mean, the internal mechanics are mostly the same, just the lack of a conventional firing system. That's the great part. No plugs, distributor caps, points, etc, etc. It's simply a timed fuel injection system, more or less just like a newer auto. They have timed gas injection like a diesel, but the diesel is "self igniting". You can study up on the combustion process of diesels, the specifics are not really important here.

I wish ALL engines were diesel. Imagine....little turbo diesels on the weed eater. And, you could "bore out" the injectors, honk up the pressure on the pump, black smoke pouring out the back of that puppy. Wouldn't the neighbors be impressed?

Probably why beautiful bride hires landscapers...

 

[our38]

HX and Temperature

our38,
Yes I replaced the the thermostat. My engine runs at 160*F no matter what. That was not the case when I got the boat.

-Do you have a waterheater on your boat and is it plumbed into the engine coolant circuit? Why do I ask? Well I found that the waterheater coolant circuit was restrictive and slows the coolant flow enough that the engine would overheat if operated for any length of time over 1800rpm. The pic of your thermostat shows a short/small hose running from the top of the coolant pump to the thermostat housing. That is the bypass hose and if you hook the waterheater up to those nipples the engine will NEVER starve for coolant flow. This was the main thing that kept my engine from running cool. Its an easy mod, just use standard 1/2" automotive heater hose, change the barbs on the waterheater to match. Prime the coolant circuit during installation so there is no significant air trapped.

-Replacing the thermostat is as easy at the 57 Chevy you used to work on....

Hope that helps, RT

It all seems to running fine, for now. Not too sure it reached 160*F though; I was just so excited that I had good water flow out of the exhaust, the temperature was staying low, and the engine seemed to be running smooth at 700 (or so) RPM's.

Yes, I do have a water heater, but since the engine is running cool now, the circulation must be fine. It looks like it could still be replaced though, just not right now. We took it out for a tryout today, and it worked wonderfully.

 

[our38]

HX and Temperature

38, I just thought I read earlier where the engine was running 140, maybe 150 degrees. Too cool for fuel burner.

And Mr. Thomas said it right. If you can change a thermostat on the Chevy, this one will be a whiz-bang for you.

And do not let the diesel "intimidate" you. One of the many reasons that I like diesels are their simplicity. I think a lot of people are skittish about them because they did not grow up with them in their first cars. If you can work on a horrible gas burner, the diesel will be a pleasure. I mean, the internal mechanics are mostly the same, just the lack of a conventional firing system. That's the great part. No plugs, distributor caps, points, etc, etc. It's simply a timed fuel injection system, more or less just like a newer auto. They have timed gas injection like a diesel, but the diesel is "self igniting". You can study up on the combustion process of diesels, the specifics are not really important here.

I wish ALL engines were diesel. Imagine....little turbo diesels on the weed eater. And, you could "bore out" the injectors, honk up the pressure on the pump, black smoke pouring out the back of that puppy. Wouldn't the neighbors be impressed?

Probably why beautiful bride hires landscapers...

Clp, I'm going to try to take it out again tomorrow (if I have crew) and push it a little harder, to see what the temperature goes up to. I don't think it made it up to 160 today, but maybe 150. I'm not opposed to replacing the thermostat, I just don't want to open a new can of worms for a couple months while i can go sailing whenever I want, at the end of every day of the week (weather permitting). When the weather starts to change, I can spend as much time down below as I want; close the hatches, turn on the music, and start tearing things

If you have a link to some literature I could read, regarding the temperature these things should run at, I'd really like to have a better understanding.

 

[mherrcat]

I wouldn't waste the money replacing the thermostat. The only reason I replaced mine was that I discovered the idiot previous owner had installed a t-stat that didn't fit. I mean it literally didn't fit. The flange on the t-stat was smaller than the recess it was supposed to fit in; it let coolant flow around the t-stat rather than through it and just rattled around inside the housing. In the process I also bought a new temperature sending unit that it turned out I didn't need.

 

[toddster]

back to the zinc

Hmm... So I sent away for a H/E zinc and installed it last week. Not that the boat is likely to be operating in sea water much in the near future. Anyway, the zinc was just sort of lightly crimped into a brass plug. It wiggles around but doesn't fall out. I'm not sure that there's likely to be much actual electrical connection there. Is that normal?

 

[mherrcat]

Those zincs usually screw into that brass plug. You can buy the zincs without the plug and just screw them into an old plug if you have one; that is, if you can get the old zinc out of the old plug. I have done that and it works. If I have to buy a zinc that includes the brass plug, when it eventually needs replacement I try to remove the old zinc and keep the plug. If the zinc is loose when you buy it, just use a pair of pliers to tighten it up and it should be fine; if you try to do that with a several month old zinc it will probably crumble to pieces. That's what makes it hard to get them out of the plug sometimes.