Need help with over heating.

[POPPA-T]

THX to all for the reply's. While most of the things mentioned by all of you has been done there some things I have not tried yet. I will be making a short two day trip on the fourth. If there is time I may try one or two of them. THX again and I will keep you all posted as to the out come.

 

[Baker]

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

I don't really have much to add to this thread other than to be careful about making linear relationships with RPM and percentages of power. That is exactly what you did there. And with a turbocharged engine, it is likely wrong. Wrong in your favor(conservative) but likely wrong nonetheless. Even with an NA engine the power curves aren't linear. Anyway, the only way to know is look in the manual.

PS....it IS 80% of available RPMs but likely not 80% of rated power.

 

[FlyWright]

Poppa,

Here's a link to a post about the Barnacle Buster I PMed you about yesterday. Your symptoms sound a lot like mine. Hope this helps.

http://www.trawlerforum.com/forums/s6/barnacle-buster-magic-elixir-20930.html

 

[timjet]

A previous poster mentioned the thermostats.
Check the easy stuff first, and go to boatdiesel.com for more info.

 

[obthomas]

Overheat in these engines is rarely because of the coolant side. First check that you have seawater flow out the exhaust. The oil cooler is first in line after the pump and needs to be clean because it removes about 1/3 of the heat. The aftercooler is next and you want to check the bottom because it can fill with sludge from used zincs restricting the flow. next is the heat exchanger. Flow enters the back and goes down half of the tubes and turns around and comes back making the heat exchanger a two pass unit. As was described in an earlier post if the rear rubber cap is distorted seawater will bypass the heat exchanger and exit without cooling. The last problem area is the exhaust elbow. If it is not clean it provides the back pressure to distort the rubber cup on the back of the heat exchanger. When the cooling systems of these engines are clean and the thermostats working these engines will operate at a maximum rock solid 180 degrees all the way to WOT.

 

[Pgitug]

You say you inspected the heat exchanger tubes. Then you said that you flushed the fresh water side for an hour. That is not long enough for most flush treatments. NAPA has a Diesel engine flush that you run, WITHOUT the thermostat installed, for six to eight hours. Then the water drains out the color of coffee. The fresh water side will scale over, especially if you use the Yellow antifreeze. Should use NAPAs diesel antifreeze. Anyway, the flush brought my engine temps down where they belonged.

 

[Xsbank]

A coolant filter is a useful device - my Cummins has one that I change each year.

 

[POPPA-T]

Again THX to everyone for the replies. I got a chance last week to change the rubber boot. I found the old one had flexed out of position. Installed new boot. Got to try out today, results 2500 rpm 150 degrees. WOT 180 degrees. Next time I have engine problems I know who to contact.

 

[FlyWright]

Great to hear, Poppa-T! Looks like we have a winner.....Koliver!

Post #6

Trawler Forum - View Single Post - Need help with over heating.

 

[koliver]

You are welcome Poppa T.

Nice to see my experience has helped someone else.

Now if I could stop being the Guinea pig and get bored by having no issues on my own boat.

 

[FF]

"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."

The hassle with old coolant (over 3 years) is it can turn into a mild ACID..

That is why most AF mfg ask you to change it , newer engines have lots of aluminum , that dissolves easily.

Any drug store or truck stop will sell PH strips to see .

 

[bayview]

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.

What you cant see is the galvanic action between the many different materials in a modern engine when the coolant looses its additives.