Heat exchanger oil cooler life expectancy

[Nomad Willy]

How long do heat exchangers running in sea water last before they start mixing fluids? I'd like to get new heat exchangers BEFORE I get sea water in my gear box or engine. The bigger heat exchanger in my boat has a zinc anode to protect it but the oil coolers do not. I could live w sea water in my engine cooling system but sea water in my transmission would far worse than a bad day.

 

[RickB]

How long is a piece of string?

If you have been running them long enough to worry then replace them. Of course that doesn't mean you can't get a case of "infant mortality" with a brand new unit.

There just aren't any guarantees.

 

[jleonard]

I am in the process of replacing mine on my Ford-Lehman. The tranny cooler and oil cooler are the same part #). They are 6 seasons old, all in salt water but with a long fresh water rinse each fall (up the Ct river).

I plan on doing some long cruising (like all next summer) and I don't want to be interupted by a failure.

The old ones look good, but then again I can't see everywhere. These coolers are only $100 each, so that's cheap insurance.

*

*

*

 

[Keith]

Bob Smith of American Diesel gave me the following replacement hours, based on copper/nickle heat exchangers:

Transmission Cooler: 2000 Hours

Oil Cooler: 2700 Hours

When I bought my boat, I just replaced both to have a baseline. Had the old ones cleaned and pressure tested; they are my spares now.

 

[skipperdude]

What kind of heat exchanger do you have? I am not familiar with anything other than mine. Perhaps if you elaborate on what kind of system you have a better answer could be forthcoming

On the cat 3208 that I am working on. The only way for the fluids to mix is the coolant can disperse into the raw water of the exchanger and pump overboard. Raw water cannot enter my cooling /coolant thru the exchanger.

*I am guessing here based on how the system is set up.

*Assuming the pressure on the coolant side is greater than the pump pressure provided by my raw water pump.*I think that it is.

*Can't say for sure as I don't know how much pressure is supplied by my Jabsco pump. Judging by how much water is pumped out the side of my boat it can't be that great.

SD

*

 

[jleonard]

Keith wrote:
Bob Smith of American Diesel gave me the following replacement hours, based on copper/nickle heat exchangers:

Transmission Cooler: 2000 Hours

Oil Cooler: 2700 Hours

*The Bob Smith notes I have from the previous owners (who took his class) say 1200 hours for the oil and tranny coolers. (don't know if that is based on copper or cupro-nickle).

 

[Nomad Willy]

Thank's gentlemen and at 500hrs engine time it looks like I should'nt be worried about it yet.*

Dude, *And when you have a small hole in your heat exchanger and the coolant goes into the sea water side your cooling system pressure will go south and the engine will probably boil and overheat and I'm sure sea water will find it's way into the engine coolant but much less quickly than I thought re the pressure differential.*

 

[skipperdude]

nomadwilly wrote:
Thank's gentlemen and at 500hrs engine time it looks like I should'nt be worried about it yet.*

Dude, *And when you have a small hole in your heat exchanger and the coolant goes into the sea water side your cooling system pressure will go south and the engine will probably boil and overheat and I'm sure sea water will find it's way into the engine coolant but much less quickly than I thought re the pressure differential.*

*That's my issue I am loosing coolant but can't figgure out how.

So you say if the coolant gets low sea water will go into the coolant side?

That is if I have a leak in my tube bundle. Correct?

Sd

 

[Nomad Willy]

Yes. I'm following this because on the last overnight trip I made I found the coolant and the lube oil down. Topped off both and when I got home the coolant was down again. Have'nt looked for the leak yet *...I'm very busy w winterizing stuff now. But I was worried about the oil coolers. I was afraid to check the transmission oil. I'll look at it tomorrow.

Gear oil looks fine

*Here is my heat exchanger on the bulkhead aft of the engine. It was a custom installation that I like much better than the sea water in the exhaust manifold.


-- Edited by nomadwilly on Tuesday 22nd of November 2011 12:16:10 PM

 

[sunchaser]

Boatdiesel has a good thread going on this subject. It would appear some Cummins are with short lived transmission coolers.

 

[koliver]

Easiest insurance is to pull them, disassemble, clean and thoroughly inspect. When I did this at 4500 hrs, all appeared factory fresh, so next inspection is a ways off yet.

 

[millennium]

Clean with what? Vineger? Ridlime?

 

[jleonard]

First off simply flush them with water (garden hose) and see what they look like. I use a brazing rod or a .22 cal rifle bore brush if they have obstructions. Then I rinse again. That usually does it.

*

*

*