Need help with over heating.

[POPPA-T]

I have a 1982 40 foot Albin Trawler. Powered by a single Volvo TAMD40A. Engine starts and runs great from idle to 2700 rpm, temp is 180. At 2800 rpm temp goes to 185 anything above 2800 rpm temp keeps rising. I have let it get as hot as 195 before slowing to 2600 rpm. Engine doesn't make black smoke at any speed. I have taken apart and cleaned heat exchanger, changed impeller, I have cleaned the fresh water side of the cooling system by running an approved cleaner through the engine for a hour. Can anyone tell me if I might be missing to do something??? Prop size is a 24X18 three blade.

 

[psneeld]

What is the operating temp spec?


My Cat 3208s were designed to run 195...some newer Cats run over 200 I am pretty sure.

 

[hmason]

I'm not an expert by any means, but 195 at 2800 rpm would not concern me if when slowing down, the temp drops quickly.

Howard

 

[Bay Pelican]

Have you checked the heat exchanger(s). Open them up and see if any of them is partially blocked.

 

[ancora]

When I first bought our Nova sundeck with twin VOLVO TMD40s, we had the same problem. I finally removed the tube that runs from the salt water pump to the oil cooler and found it impacted with salt, as the PO never used the boat. That was 15 years ago and have not had that problem since as the boat does not "sit."

 

[koliver]

I used to have a pair of TMD40s. I don't know if the TAMD40 has the same heat exchanger, (HE) but assuming so, this is what I found:
On the aft end of the HE, there is a black rubber cover with molded in hose attachments (boot). Inside, that boot has a centered slot in the piece of rubber that separates the top section from the bottom section. The brass end of the dividing part of the HE slips into this slot. In higher RPM conditions, the water pressure is sufficient to distort the rubber and blow coolant past the separating brass piece, so that coolant doesn't travel through the 100+ tiny tubes in the HE, but immediately goes to the exit hose and out of the HE, uncooled and back into the engine. I replaced the rubber piece and had instant relief from this condition, only to have it return when the newer boot started doing the same thing a few years later.
Replace yours and you should get relief. I solved the problem completely by swapping in a pair of TAMD41s that have a better HE design.

 

[Capt.Bill11]

What temperature is your thermostat set to open at?
Did you clean and back flush all your coolers?
Is the thru hull to your strainer clean/clear?
Have you confirmed the temperatures you see on the gauge with a mechanical gauge or IR temp. gun?

 

[POPPA-T]

Yes Pelican the heat exchangers were opened an I passed a brass rod through all the tubes.

 

[POPPA-T]

I used to have a pair of TMD40s. I don't know if the TAMD40 has the same heat exchanger, (HE) but assuming so, this is what I found:
On the aft end of the HE, there is a black rubber cover with molded in hose attachments (boot). Inside, that boot has a centered slot in the piece of rubber that separates the top section from the bottom section. The brass end of the dividing part of the HE slips into this slot. In higher RPM conditions, the water pressure is sufficient to distort the rubber and blow coolant past the separating brass piece, so that coolant doesn't travel through the 100+ tiny tubes in the HE, but immediately goes to the exit hose and out of the HE, uncooled and back into the engine. I replaced the rubber piece and had instant relief from this condition, only to have it return when the newer boot started doing the same thing a few years later.
Replace yours and you should get relief. I solved the problem completely by swapping in a pair of TAMD41s that have a better HE design.

THX for the quick reply. You have given me a direction to look and maybe an inexpensive fix.

 

[Heron]

THX for the quick reply. You have given me a direction to look and maybe an inexpensive fix.

Hopefully!. I have that engine (2002 model P) in my boat and the Previous owner had the exact problem at 1400 hours.. From the logs, He did all the cleaning, rodding etc of the exchangers and still had an issue. Turned out to be a failing temperature sensor. Replacement cured the problem..I'm sure the other stuff didn't hurt!

 

[Conall63]

195 is not a hateful temp. Diesels run better when hot. I'm' not familiar with the engine, but 2800 sounds close to wide open throttle where one would expect the temp to creep up.

I had a similar issue Heron described, but it was in my dash gauge, and a faulty wiring connection that caused an over heat alarm. The wire was loose on the spade, and was causing the needle to jump around on the high side.

Conall

 

[Capt.Bill11]

THX for the quick reply. You have given me a direction to look and maybe an inexpensive fix.

Check that the thru hull to your strainer is clear and check that the temps you are seeing are true before you start buying and randomly replacing things.

 

[Xsbank]

When did you last replace your coolant? It does wear out, you know?

 

[kulas44]

Wear out ? Even if it did "wear out" it wouldnt cause overheating.

 

[Heron]

195 is not a hateful temp. Diesels run better when hot. I'm' not familiar with the engine, but 2800 sounds close to wide open throttle where one would expect the temp to creep up.

Actually Max RPM on this motor is 3600, with cruise at 80%, that's 2880. Mine runs about 185 degrees at that speed..

 

[bayview]

As Bill said verify the strainer and scoop are clean then look at the next thing upstream and the hose in between. Junk can travel through the system but the first small opening will usually catch it and block flow. Also look for previously missed impeller blades that may travel.. Lastly and least likely check the exhaust shower mixer. Rust can block holes and cause reduced flow.

 

[obthomas]

I have long time experience with the TAMD40s. The exhaust elbow can be a huge problem. If it is mostly blocked the saltwater system will pressurize and distort that rubber end cap Koliver talked about. Your two pass heat exchanger becomes no pass. Also you need to make sure the oil cooler and after cooler are also clean. Take them off and run dowels through them. Check for zinc sludge in all the heat exchangers. Once you get the entire seawater system clean the engine will run about 170 degrees and then 180 degrees because there are two thermostats. My engines run a rock solid 180 degrees in the 2000 to 3500 rpm range. Good luck. The TAMD40s are great engines.

 

[Marlinmike]

Any steam when you are running up at 2800 rpms, what rpms does the boat get up to at wide open throttle?

 

[Xsbank]

Yes, in a diesel, worn out coolant can cause overheating. Do the research.

Why else would you bother replacing it, otherwise?

 

[rardoin]

Yes, in a diesel, worn out coolant can cause overheating. Do the research.

Why else would you bother replacing it, otherwise?

Depletion of corrosion inhibitors, which can be added.

 

[ancora]

Re the boot problem: I got a piece of sheet brass and folded it over the part that projects into the boot adding 3/32" to the projection. Epoxied it in place and problem solved. That was fifteen years ago and it's still workin'.

 

[kulas44]

My Ford truck (diesel) is a 2000 year model and has never had the antifreeze changed or even added to for that matter. Thats 15 years. It doesnt look worn to me. I think I'll keep running it awhile longer.

 

[Xsbank]

Proof:
Good luck with your old coolant.
"When water and coolant in your engine heats and expands, air bubbles are formed from localized boiling. The general term we often use is cavitation. The scientfic term for that specific localized boiling I mentioned is nucleate boiling. – I can’t believe I found a picture of this! These bubbles collapse or explode against the outside of the cylinder liners and take a portion of the steel with it. This is called cavitation erosion. These little bubbles are imploding at the cylinder liners at pressures up to 50,000+ psi. They start blasting into the cast iron liner and causing a “pitting process” that continues over and over until they tunnel their way into the combustion side of the cylinder. If coolant enters the combustion side of the cylinder you’re looking at an engine rebuild with a bore and resleeve job. Enter SCAs - Supplemental Coolant Additives – recommended maintenance for your Ford Powerstroke cooling system. What they are in a nutshell is a liquid poured into your cooling system at a recommended interval. A chemical reaction caused by heat and metal contact causes the liquid to become a solid "scale" as it coats the outside of the steel cylinder liners. This "scale" creates a sacrificial liner that is removed by the tiny explosion of collapsing bubbles instead of the steel cylinder liner. So the theory is that the pitting of the liner won’t occur. In order to replace the void and the displaced scale that was removed upon implosion, you must have residual unconverted SCA (liquid form) still floating around in the system. The displaced scale is now an abrasive partical floating around in your system which stays there until flush time. All the while these little pieces of abrasive scale are wearing at water pumps, hoses, insides of radiators, etc."

 

[psneeld]

Sure...cavitation erosion...


I studied it like mad when I bought my powerstroke and then switched to OAT antifreeze.


...but not overheating...had a friend loose an early powerstroke
to cavitation erosion...never saw it coming....certainly not high coolant temp


Also never heard of overheating from just "old" coolant...other issues yes...just not overheating.


Also I think I read cavitation erosion isn't common in all diesels....especially the older, heavy metal, lower compression ones.


http://www.forddoctorsdts.com/articles.html/_/dtsarticles/cavitation-erosion-r27


Cavitation erosion is a phenomenon that is well known with relation to diesel engines. Cavitation is the formation of vapor bubbles of a flowing liquid in a region where the pressure of the liquid falls below its vapor pressure. Erosion is the result of the formed vapor bubbles rapidly collapsing which produces a shock wave that can remove small amounts of metal from cylinder walls. As this process repeats pitting of the metal will occur and over time holes will form. Irregularities in the metal surfaces from casting or machining and the cavities from the erosion process itself encourage the formation of these vapor bubbles.


Yes hot coolant...but within specs...it's the low pressure area that causes the "low pressure boiling"...not high engine temp.

 

[kulas44]

Thats all well and good, and maybe they sold a bunch of there snake oil to counter the effects. I dont use it. I do use Nalcool in my Detroits, for no reason other than thats what I was taught. Just FYI, the PowerStroke diesel engine doesnt have liners, its a parent bore block.

 

[Xsbank]

My boat is keel cooled, has almost 200 litres of coolant. I also have a commercial duty Cummins. Running at full throttle (it is rated full throttle 24 hours) I would get the coolant temperature rising until I throttled back (throttle is the wrong term) and coolant overflowing the overflow bottle. I immediately replaced all the coolant and now full throttle has no temperature rise and the coolant level stays constant.

It really matters nothing to me if anyone wish to abuse your engines. I would refer you to the "finding a good mechanic" thread.

 

[River Cruiser]

You may be over propped if your engines won't reach their specified wot rpm. My specified wot is 3000, I was getting 2800 with year old anti fouling the way the boat is normally loaded. It would start getting warmer (180f-190f) at any rpm over 2600. I swapped the 20x22 props for 20x20 and the temp is rock steady at 170f at 2800 cruising RPM. I normally run 1000 to 1600 depending on conditions and current on the river and temps run 160f. The thing to remember with a diesel is the governor controls the fuel delivery when you set the throttles, in a over propped or overloaded condition the governor will increase fuel to maintain the rpm. More fuel = more heat to dissipate. This will also cause a increase in EGT which is detrimental to engine life. Make sure your engines are in proper tune, tachs are correct and that you can reach specified wot rpm. Good luck


Sent from my iPad using Trawler Forum

 

[kulas44]

I dont need a good mechanic, I are one. 200 liters of coolant,wow, thats a lot. I definitely would never change that much. In a previous life, back when I was a heavy equipment/ag tractor mechanic, the big 4wd tractors like Stiegers and some Fords used the Big Cam Cummins 855 rated from 350 to 550 HP. After a lot of research it was determined by Ford that they did in fact have erosion/cavitation issues. IIRC it was from the different metal of the liner and the block and the interaction with the coolant. Southern tractors that ran straight water with corrosion abatement additives didnt have those problems.

 

[Xsbank]

Buying the additive package for 200 litres was more expensive, or at least comparable to replacing the coolant.

 

[bayview]

You don't say but this must be a new phenomenon, in that case you are correct to be concerned.