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Universal 5432 Engine Running Temperature

footrope

Contributing Partner
Blogs Author
During the 15 years I've owned the E38, I have generally had excellent performance from the 5432 diesel engine. It drives the boat at 6+ knots (3-blade feathering prop) and runs smoothly. The engine is under the companionway and is closely confined in there (forward head and shower interior configuration, galley starboard aft). I have ventilation hoses run under there but no fans to cool the compartment. I have been using the Universal 160 degree thermostats continuously.

In its history, at approximately 2000 rpm cruise power, the engine warms up gradually. Once everything is up to temperature after 2-3 hours its coolant temperature is around 170-175 degrees F. The temperature gauge value has been roughly confirmed (+/- 5) using an infrared temperature measuring device pointed at the thermostat housing.

As the time at cruise rpm continues beyond 3 hours I usually see the temperature continue to slowly rise, creeping up to 180 and above, particularly in recent years. I control or stop the rise by throttling back 100-200 rpm. Cleaning the heat exchanger and clearing the strainer didn't change the situation. The Oberdorfer 202M-7 pump is old, but water flow is good and seems unchanged over the years. The 3/8 inch reducing elbows that are reported by one shop to be "standard" size for the Oberdorfer have a little calcium build-up. No bearing issues or anything with the drive mechanics of the pump.

These engine coolant temperature characteristics do not sound like what everyone else is experiencing, regardless of engine type or age.

At the beginning of our cruise this year, we limped in to Everett for a planned stop with a hot engine that required much more severe rpm reductions than usual. The apparent cause of the sudden worsening of the problem was a gummed-up and cracking seawater impeller. Cleaning that up and replacing the impeller returned the cooling to its usual gradually increasing self. I used a solution of Unchloric acid in the heat exchanger, which was needed anyway after seeing the condition of the impeller housing. All the impeller vanes were cracked. After some consultation, I decided to get some real engine flush solution (Fleetguard) and while I was doing that I decided to pop in the 180 degree thermostat that I had purchased as a spare during the 2016 engine problems (oil in coolant thread). So, I doubled the mooring lines on the boat and ran it in gear at 2000 rpm for almost 2 hours to make the flush solution work. Amazingly (or maybe as expected), the coolant temp rose quickly to 180 degrees (+/- a needle width) and stayed there the whole time.

The results of the flush were good, even super good. The flush cleared out more oil from the cooling section of the engine. The 180 degree thermostat tryout was wildly successful and it remained in the engine for the rest of the cruise with the same steady 180 degree performance (over a month and 120+ hours of engine operation). Below is a picture of the two thermostats. My tentative conclusion about this is that the physically larger 180 thermostat allows higher coolant flow through the system and that makes the heat exchanger more effective. I changed the two bronze elbows on the seawater pump to slightly larger diameter machined elbows, but other original bronze 3/8 inch elbows remained upstream on the strainer. I don't think there was any seawater flow improvement.

Put me, finally, in the group that recommends trying the 180 degree thermostat in the 5432, if everything else isn't helpful.

20180811_143658-annotated.jpg

Do ya think this could be a problem?
20180806_153719-small.jpg
 

Shadsboat

Member I
E 38 engine model M5432

Hello,
I was told that the heat exchanger should be removed and "boiled out" periodically. What period, I don't know... I understand that it is made of
pretty much s
olid bronze so I hesitate to simply replace it. Have you done this sort of project and if so, where do you get this thing boiled out? I am local to Gig Harbor as well with my 38 berthed in Longbranch Marina (Filucy Bay). I am a little intimidated about doing the R&R but am also intimidated by numerous other things that I eventually overcome...
Thanks,
Paul
1984 E38 Amazing Grace
 

Frank Langer

1984 Ericson 30+, Nanaimo, BC
I have found that 5 years is too long, as our heat exchanger looked very "grungy" inside by then, so I get it done every three years. A local radiator repair shop does it for about $80.00 includes new gaskets at both ends and spray paint to protect it. Some guys do it themselves with muriatic acid, but I prefer to have the shop do it and pressure test it as well.
After draining the coolant it is not hard to remove the coolant hoses. Coolant should be replaced periodically anyway.
Frank
 
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Alan Gomes

Sustaining Partner
I have found that 5 years is too long, as our heat exchanger looked very "grungy" inside by then, so I get it done every three years. A local radiator repair shop does it for about $80.00 includes new gaskets at both ends and spray paint to protect it. Some guys do it themselves with muriatic acid, but I prefer to have the shop do it and pressure test it as well.
After draining the coolant it is not hard to remove the coolant hoses. Coolant should be replaced periodically anyway.
Frank
I also wonder whether switching to the 180-deg. T-stat will require more frequent cleaning of the heat exchanger. If I'm not mistaken, the reason Universal went with a 160 or 165 deg. thermostat was to keep the salt from precipitating out into the exchanger. I think the engine itself actually likes to run at the higher temp and the 165 deg. T-stat is something of a compromise.
 

footrope

Contributing Partner
Blogs Author
Hello,
I was told that the heat exchanger should be removed and "boiled out" periodically. What period, I don't know... I understand that it is made of
pretty much s
olid bronze so I hesitate to simply replace it. Have you done this sort of project and if so, where do you get this thing boiled out? I am local to Gig Harbor as well with my 38 berthed in Longbranch Marina (Filucy Bay). I am a little intimidated about doing the R&R but am also intimidated by numerous other things that I eventually overcome...
Thanks,
Paul
1984 E38 Amazing Grace

Hi Paul,
We've spotted Amazing Grace at Longbranch - nice looking boat! Yes, the heat exchanger is a maintenance item, mainly the salt water circuit because it will build-up white deposits. Performance Radiator in Tacoma has done it for me in the past - about $80. I've also taken it to Federal Way Automotive in Milton on south 99. They were about $130 three years ago.

Removal of the heat exchanger is fairly simple, if only it was easy to reach the mounting clamps and the hose clamps and have a little bit of leverage to tug on the hoses. An empty heat exchanger is still heavy because it is a copper alloy that is similar to bronze. I have done the R&R several times over the years. It is a problem of access. I have done it from the lazarette after removing the muffler and getting the exhaust hoses tucked out of the way. Once I became familiar with the hoses I was able to do it by laying over the top of the engine and through the port side access in the quarter berth, and reaching through a tight spot on the port side of the engine to get the coolant hose loose that is behind the starter.

The other mess you have to plan for is the loss/recovery of anti-freeze from the engine coolant circuit. I've not developed a nice clean method of recovering and re-using good anti-freeze. I pump it out of the engine bilge later and discard it at a household hazardous waste collection site. As others have replied, 3 years is probably a good interval, depending on how much you use the boat. Sitting unused is worse in a lot of ways than if you use the boat in the winter. It is possible to winterize the seawater side with fresh water, again with some preparation, and it is fairly simple.

Re-filling the anti-freeze can be a challenge. Removal of the thermostat is recommended to ensure you can pour fluid into the passage that goes to the coolant (water) pump. My engine has to be run for a couple hours to get all the trapped air out. It usually takes between a pint and a quart to bring it back up to full once the air is out. Sometimes I loosen a coolant hose on the water heater to ensure any trapped air is released from there.

PM me sometime if you want to discuss it further. I'd love to see your boat.
 

footrope

Contributing Partner
Blogs Author
Yup. All that salt water coming in over 30+ years is bound to have left a memory.

View attachment 25110

I recognize that picture. My fittings haven't gotten that bad. Even after opening that horror show of a seawater pump my elbow fittings looked like this.

20180811_162153-crop.jpg

The boat wasn't cruised for two seasons and the cracks in the impeller blades were a bigger shock than the deposits. There was even a little wear from the deposits. That is a nitrile impeller.

20180806_154115-small.jpg
 
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footrope

Contributing Partner
Blogs Author
I also wonder whether switching to the 180-deg. T-stat will require more frequent cleaning of the heat exchanger. If I'm not mistaken, the reason Universal went with a 160 or 165 deg. thermostat was to keep the salt from precipitating out into the exchanger. I think the engine itself actually likes to run at the higher temp and the 165 deg. T-stat is something of a compromise.

Good question and a good possibility. Maybe someone will comment on that. Too soon for me. The explanation I heard about the salt precipitation and use of lower temp thermostats was from direct salt water cooling on older or smaller engines where salt water was sent through the block - no anti-freeze or heat exchanger was used. Later engine manuals (M-40) specify higher operating temps. Both versions may be true.
 

Alan Gomes

Sustaining Partner
Good question and a good possibility. Maybe someone will comment on that. Too soon for me. The explanation I heard about the salt precipitation and use of lower temp thermostats was from direct salt water cooling on older or smaller engines where salt water was sent through the block - no anti-freeze or heat exchanger was used. Later engine manuals (M-40) specify higher operating temps. Both versions may be true.
Yeah, that's certainly true with RW cooled engines, like my Yanmar 1GM. My 1GM is a ridiculously cold blooded beast! But the RW side of your exchanger would be subject to similar issues, it seems to me. Anyway, I guess more frequent inspections of the HE for now would be prudent. I would think your engine itself would be happy with the higher temps. Maybe Universal went with the 165-deg T-stat on the (correct) assumption that most owners are not going to do regular maintenance on their HE.
 

supersailor

Contributing Partner
I have been running a 180 degree thermostat in my M-25XP for several years. popping the ends off the heat exchanger at the end of each season hasn't shown any additional buildup. You guys on the lakes shouldn't have any worries about the heat exchanger at all.
 

footrope

Contributing Partner
Blogs Author
Unchloric acid and heat exchangers

Thanks for the input Bob. I have a friend with a M4-30 in a Bristol 32 and he runs a comforting 180 degrees, rock solid, and has not had any acceleration in his heat exchanger maintenance.

Alan, do you use any de-salting or de-scaling product through your Yanmar or do you flush the engine with fresh water periodically to keep down any random salt build-up?

The connection to this thread is that the UnChloric acid can also be used to clean calcium and rust from metal parts. Oxalic acid is the active ingredient in Davis brand FSR that is used to bleach rust stains from gelcoat, for instance. I talked to the Marine Sanitation expert about cleaning copper alloy heat exchangers and he said to reduce the soak time to about an hour. So, when I cleaned my heat exchanger during this troubleshooting process I did it without removing it from the boat or disturbing the coolant side. I rigged 5/8 inch hoses from the HX seawater inlet and outlet to allow the solution to sit in the HX. We reduced the amount of the acid crystals for the amount of water we thought we needed, about a pint. After an hour or so we flushed with fresh water into a bucket (don't pump it overboard) and went on our merry way. I will inspect the heat exchanger physically this winter, so I'll update the condition and see if more work is needed. This acid works slower than muriatic, so there may be a need to extend the time, carefully. If I remove the HX I could soak it in a pail of the solution and monitor the performance and any effect on the metals. Marine Sanitation has the instructions for its use on their website, although heat exchanger cleaning is not mentioned specifically.

I heard about Unchloric Acid this summer and I buy it at Marine Sanitation in Seattle, next to the Fisheries Display Store. They sell it for de-scaling waste pipes and toilet bowls. It contains Sulfamic and Oxalic acids and is sold in 1 lb. plastic jars. It is mixed with a gallon of warm water. The acids are not as strong as Muriatic acid, which contains Hydrochloric acid. The advantage is that it is safe for holding tanks and sewer systems and can be disposed of via pumpout when it is convenient. If it is used for other purposes it can be poured down the drain rather than taken to a hazardous waste facility. My toilet bowl had visible deposits from the 2 years of inactivity. Anyway, 24 hours in the toilet bowl and adjacent hoses did wonders for the appearance of the bowl. Supposedly it also helps de-sludge the tank, and there is a different product for the specific treatment of holding tanks that is used on an ongoing basis. We used that during this cruise, results are inconclusive at this point.
 

llenrow

Member II
Ok have to chime in. I have a 1985 e38 less than a year. Cooling sx maintenance unknown. Coolant level normal, took cap off WP—-impeller perfect. I’ve noticed the temp creep —-1800–steady at 180, 2000, steady at 190, but then intermittently back to 180, 2200 pushed 200 so I always backed off.

Today I was determined to test, Ran it to my usual 190 at 2000—takes a while to ge up there. Then, I opened it up to 2400 and watched. crept up and down and up and up waiting for arming light—-nothing. Finally at 205/210 or so engine stopped, no sputter, just stopped — yikes

Safety mechanism???? Waited a few minutes, said a quick prayer and (TYGod) started right up and ran fine again at lower temps—-and lower rpms. I’m reading all the talk about thermostats and boiling exchangers ——-what’s my next step?

Thx

Doug, “Island Bird” Fox Island WA
 

Alan Gomes

Sustaining Partner
Thanks for the input Bob. I have a friend with a M4-30 in a Bristol 32 and he runs a comforting 180 degrees, rock solid, and has not had any acceleration in his heat exchanger maintenance.

Alan, do you use any de-salting or de-scaling product through your Yanmar or do you flush the engine with fresh water periodically to keep down any random salt build-up?
I do have a "T" valve set up so I can draw the water out of a bucket. I use a fresh water rinse as well as a product called Salt Away.
 

supersailor

Contributing Partner
This sounds like an old sticky thermostat and/or a plugged heat exchanger. I would first replace the thermostat. It's by far the easiest thing to change and the most likely problem. The thermostat should be changed every few years but it is one of those deferred items that few of us think about. My engine did just the opposite right after I bought the boat and the engine never warmed up above 120 degrees. The ancient thermostat was stuck wide open. Yours may be stuck partially closed.

Take the ends off the heat exchanger this winter to see how much scale has built up inside. If there is a significant amount, clean it with the methods suggested earlier in this thread. Also check the intake hose. It is difficult to replace so it gets deferred. Mine fell apart with a tug. Scary when the hose is below the waterline. Be sure all hoses below the water line are double clamped. A hose coming loose could mean the end of your boat.

Welcome to the Ericson family. We think we have the bestest boats out there and this site is the icing on the cake.
 

llenrow

Member II
This sounds like an old sticky thermostat and/or a plugged heat exchanger. I would first replace the thermostat. It's by far the easiest thing to change and the most likely problem. The thermostat should be changed every few years but it is one of those deferred items that few of us think about. My engine did just the opposite right after I bought the boat and the engine never warmed up above 120 degrees. The ancient thermostat was stuck wide open. Yours may be stuck partially closed.

Take the ends off the heat exchanger this winter to see how much scale has built up inside. If there is a significant amount, clean it with the methods suggested earlier in this thread. Also check the intake hose. It is difficult to replace so it gets deferred. Mine fell apart with a tug. Scary when the hose is below the waterline. Be sure all hoses below the water line are double clamped. A hose coming loose could mean the end of your boat.

Welcome to the Ericson family. We think we have the bestest boats out there and this site is the icing on the cake.


Thx. Hope to see you up in the strait some day.

Doug
 

footrope

Contributing Partner
Blogs Author
Here are the Kubota part numbers for the 180 degree thermostat and gasket.

20180916_165231-small.jpg

I can't wait to see the thermostat you have in there, Doug. I have a couple spare 160s that you can try if you want. I am going to get a spare 180 degree from Kubota as soon as I can. I'll be calling the dealers in Shelton and Silverdale. I'll let you know.

Instructions on replacing it follow below, assuming a similar configuration to my picture.

To begin, take the hose off the cover fitting, see the black arrow. You might loosen the other clamp on that hose so you can rotate it out of the way, optional. (An original hose may be fragile. I don't remove the temp sensor wire. Optional.)
Remove the two hex bolts that hold the cover on the housing. Lift the cover.
You now can see the thermostat and gasket.
Remove gasket - you might be able to re-use it.
Remove thermostat. The Universal 160s have "160" embossed on the copper element at the bottom.
Put the new thermostat in, spring end down, and then put the gasket over it.
Bolt on the cover, then restore the hose.
Ready to start and leak check.

20180831_214310-arrow.jpg
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
For the record, my 5432 runs at 180 degrees all the time, even if WOT for a while, and under all conditions.

That is, the temperature dial reads "180." I've never checked to see which thermostat.
 

footrope

Contributing Partner
Blogs Author
When I have purchased thermostats for this engine in the past, I've rattled off the engine manufacturer and model (Universal 5432 diesel) and the thermostat I get is the 160 degree. The parts person has never asked me what temperature thermostat I want. It is in a Universal by Westerbeke blue box (t-stat and the gasket) labeled Thermostat Kit, with the Universal part number 200218. I think I paid $27 and change for this in August, from a Seattle dealer, which is pretty reasonable.

I wondered if I said "M-40" or "M-40B" engine model if the thermostat kit would be the same? I called the Seattle dealer and he says even the later engines specify Universal thermostats at 160 or 165 degrees. There is a different part number for the M-40B, and he said he thought it was due to a different diameter thermostat. I can't measure mine at this time, but I wonder. I plan to compare the Kubota and Universal thermostats after I get my spare 180, to see if I can verify the 180 might be higher flow. The differences are striking when they're side by side.

It may be possible to go through the seawater system and increase the flow rate to get better results with the 160 thermostat, just by changing fittings or hoses. That is a lot cheaper than changing a pump, a strainer or getting a larger heat exchanger. The impact of seawater flow on engine operating temperature might be found in the different strainers we have. My little strainer is pictured below. I'll have to add the model number, if anyone is interested in comparing. The gunk in there, after 130+hours without a cleaning, is another story. Maybe a blog post would be the appropriate place for that.

20180911_095509-small.jpg
 

llenrow

Member II
When I have purchased thermostats for this engine in the past, I've rattled off the engine manufacturer and model (Universal 5432 diesel) and the thermostat I get is the 160 degree. The parts person has never asked me what temperature thermostat I want. It is in a Universal by Westerbeke blue box (t-stat and the gasket) labeled Thermostat Kit, with the Universal part number 200218. I think I paid $27 and change for this in August, from a Seattle dealer, which is pretty reasonable.

I wondered if I said "M-40" or "M-40B" engine model if the thermostat kit would be the same? I called the Seattle dealer and he says even the later engines specify Universal thermostats at 160 or 165 degrees. There is a different part number for the M-40B, and he said he thought it was due to a different diameter thermostat. I can't measure mine at this time, but I wonder. I plan to compare the Kubota and Universal thermostats after I get my spare 180, to see if I can verify the 180 might be higher flow. The differences are striking when they're side by side.

It may be possible to go through the seawater system and increase the flow rate to get better results with the 160 thermostat, just by changing fittings or hoses. That is a lot cheaper than changing a pump, a strainer or getting a larger heat exchanger. The impact of seawater flow on engine operating temperature might be found in the different strainers we have. My little strainer is pictured below. I'll have to add the model number, if anyone is interested in comparing. The gunk in there, after 130+hours without a cleaning, is another story. Maybe a blog post would be the appropriate place for that.

View attachment 25125

Thanks for all the information Craig. I have a new 180 t-stat and gasket on order and will update you after installation. I'm hoping for a result that behaves as Christian described.

Doug
 

llenrow

Member II
5432 running temp

Getting back after installing new 180 thermostat—-an doing a lot of inspection and reading. New thermostat made little difference in heating up to 195 at 2200—didn’t push more—except it got up there quicker as expected.

I did realize today when inspecting to learn the anatomy of the cooling system that the expansion tank was empty (was cold when noted today, and above fill line when cold previously) . I popped the manifold cap and green present but an inch or so down. I filled with bottled water (not even half a small bottle) and replaced cap—-ran up to 160 on anchor out of gear and expansion tank filled only half way to low line. I did lose some coolant in thermostat procedure but not sure that much.

My impeller is perfect, I have the 3 inch (bigger) HE that is only 3 years old installed by PO and it and hoses look solid without detaching.

I’m starting to look towards the hot water heater as my issue —-its original and in series. This means (I think) after the thermostat opens most hot coolant goes from the engine to the HWH then to the HE, then back to the engine. In the recommended bypass, the HWH accepts and restores water via the thermostat outlet/intake (the short bent line below is replaced by to and from lines from the HWE) that normally heats the engine before the thermostat opens but then has restricted flow. From the looks of mine its already restricted anyway. You can see on my attached pic of the stock non bypassed line what a questionable/bent set up that is anyway and should be bypassed I think. (Below)

So a couple questions from someone very novice at this but learning—-

1. Could I have lost enough coolant replacing the thermostat that my sea trial was hot due to that? Do I need to bleed some air out of system to get adequate coolant level back in expansion tank or can I just fill there?

2. Can I test the bypass idea by just moving the hose off the HE and running direct engine to the HE like the water heater isn’t there —-before I get too crazy? And then seeing how she runs?

3. Do I even have a problem—-considering hull speed—-I’ll never cruise much above 2000-2200 anyway

I appreciate any feedback and please let me know where I may have a misunderstanding of the system. I’ll leave you with a pic of my boat tonight at anchor from home on Fox Island with West Tacoma homes reflecting the sunset

Doug
 

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