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Diagnosing bad heat exchanger

S

steve hale

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"On my crusader 5.7 300hp powe

"On my crusader 5.7 300hp powerpack repowers, My port engine runs 30 deg hotter than starboard and climbs slowly over 3600 rpms. When we did the repower, we kept the heat exchangers and changed everything else. The old engines did the same thing. The flow from the raw pump is great, the sea strainers are clean. I can smell some antifreeze at the stern in the exhaust on the hotter engine. I'm assuming the heat exchanger is leaking slowly into the exhaust, since I will have to add antifreeze regularly to the hotter engine. It is not going over 200, so I don't think it is going out of the overflow. I do not think the heat exchangers have been cleaned in the repower. My question is this. Can I swap heat exchangers, and see if the higher temp follows the heat exchanger there by isolating my problem. Or are the ports different for LH or RH rotation motors. If it is leaking antifreeze, Am I putting the good motor at risk by swapping them? I know I could take them to a radiator shop and pressure test them, but I'm not in a metro area, and It might be a little harder than you think.
Steve"
 
"Steve:

Do yourself a huge

"Steve:

Do yourself a huge favor and replace that one exchanger. If that's the problem, fine--all fixed. If not, you have one of them replaced, right?

Jeff

PS: Are you absolutely certain there is no air leak in the system before the raw water pump? THe tiniest air leak will screw things up big time, especially while on plane."
 
Pressure test the exchangers y

Pressure test the exchangers yourself. Screw a tee fitting into one of the drain plugs and attach a pressure gauge that will read accurately down to 10 psi and a hand pump to pump up to 6 psi and see if it will leak down. If it does then block off the input and outputs on the heat exchanger and retest to localize the leakage.
 
"Good, but that won't dete

"Good, but that won't determine if there's a bunch of crud in there that's blocking water flow. you need to pull the covers off and go through it.

Jeff"
 
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