Detroit Diesel Heat Exchanger Failure

I think the problem with paddle type flow switches is the build up of salt on the arm and where the arm joins the body, this always makes in line sensors subject to falses when in a hostile enviro. I have a pipe mounted thermostat on all cooling water exits from HEX's set at 140 F or whatever temp it will go off at during normal op temps. There may be in line sensors available that are immune to the salt enviro. Had a steam boiler blow up once due to failure of the water sensing probe due to a lack of proper chemical treatment, the probe was just encased in hard crystalline material and failed to sense a low water condition.

Any updates? Any more problems? Bet ya already left town.

A plastic bag or debris of some kind may have passed over the raw inlet. With a restriction of incoming water, water pump vanes really bend over and can get abused quickly.
I have also noticed strange impeller failures after fresh replacements. What I have learned, NEVER use a (spare?) impeller with dust on the packaging. I do not have a clue what shelf life is supposed to be. But when I find a 'sposed fresh impeller failure, my personal investigation shows it was a shelf queen.

It's nice to keep spares, I try my best to rotate spares on our boat. I also do not use customer spares and encourage fresh spares. My part sources move enough to insure what I install, is NOT a dust collector.
NEVER, buy an impeller from e-bay. Remember what NOS means, New OLD stock (or older).
Big impellers start around $90 & up-to $175. Cheap compared to a whole engine.
Ruptured H/E case? We may never know the how/why. REAL GLAD to hear no main problems. I do believe there was an hidden flaw that showed it a$% (ugly part) at a time of quick temp change (raw pump failure, debris over intake, sudden raw water temp change, moon over ??? and/or just plain bad luck).

Life is good in BVI. Getting cold here in south Georgia. You could of invited a few of us, new best friends.....

Thank you for sending that picture.

You can see from the cam wear on the outside edge of the vane, this was not a new (fresh) impeller and had some time on it. This impeller was due (over?) for replacement.
If you tell me that it is new or very low hours, I need to ask;
Haw bad are your pump cams? Who is pulling your leg?

When the vanes came off, I can easily imagine a serious blockage at the cam (grate) restricting water flow. Yep, sudden water temp change.

Did you mention these were fresh impellers (picture shows different)?

If the pic is what your talking about (above), there is a leg puller among you.


AND Yes, If you can question the age of what you put in, can them. Please send pic of what you pull out. Would like to see the edge wear. You may have a bad cam (doubt it, but have to look).

I'd like to point out, if there is an exhaust/water restriction, the vanes would float and fail also, BUT there is heavy cam wear that proves the pump is pumping and not floating.

,rc

Just got the weather report from da wife. tomorrow morning (sunrise) it will be around 60f. by noon, it will be 40, freezing before sundown.
Do you need me to look closer at your impellers? Please?
,rc

Clogged H/Es would cause the impeller blades to float. You would not see the loaded wear on the blade ends from the cams. Especially with less than 50 hours......
AND, upon tear down, the raw side of the H/Es looked good.
The bypass around the inter-coolers will not allow a restriction there. The fuel cooler (inter-cooler bypass) is pass-thru straight tube and no restriction can happen there. The vanes had wear so no restriction at the dump cans, but still need to be looked at.

Still think I need to come down to double check.