Question on overheating repair or replace

[tomschauer]

If you replace the impellers every year, something else is making you run hot. What could be restricting your flow?
Algae growth, zebra mussels?

Hope you figure it out.

[bud37]

Source of the post I neglected to mention that the oil pressure runs a little higher on the starboard engine, also

In reality an engine that is running hotter should show a slightly lower oil pressure as the oil temp would be higher. The trouble is that until you get the prelim stuff done it is really just guessing . I think I might verify the temp and oil pressure gages with an IR temp gun on the sensor and a remote oil pressure gage.....that way you will know for sure and double check your dash gages.......good luck man.

[Helmsman]

If you replace the impellers every year, something else is making you run hot. What could be restricting your flow?
Algae growth, zebra mussels?

Hope you figure it out.

I think the new impeller failed. Just won’t know that until I pull it. That is what Occam’s Razor would say.

[Viper]

When you pull the impeller, check the inside pump housing, wear plate, and cam. A new impeller won't make much of a difference if this hardware is worn.

Has she ever been in salt water and if so, for how long?

[Helmsman]

When you pull the impeller, check the inside pump housing, wear plate, and cam. A new impeller won't make much of a difference if this hardware is worn.

Has she ever been in salt water and if so, for how long?

Ok. I will. Freshwater on Lake Chickamauga in Tennessee her whole life.

[Viper]

I wouldn't worry much about the exh. manifolds if she's a fresh water vessel unless further diagnosis takes you in that direction. You could have garbage or impeller pieces from a previous failure in the HE or cooler though. Impeller pieces have to be removed manually or flushed out but try Rydlyme to descale and clean the HE and cooler before removing and sending out. Of course check all the other normal things like intake hoses, connections for leaks, strainers, seacock, etc.

[Helmsman]

Source of the post I wouldn't worry much about the exh. manifolds if she's a fresh water vessel unless further diagnosis takes you in that direction. You could have garbage or impeller pieces from a previous failure in the HE or cooler though. Impeller pieces have to be removed manually or flushed out but try Rydlyme to descale and clean the HE and cooler before removing and sending out. Of course check all the other normal things like intake hoses, connections for leaks, strainers, seacock, etc.

Thanks! I won’t be able to get to the boat until January, but will follow that approach. Just have to pick a set of warm days!

[mjk1040]

Ah darn! Viper beat me to it. Descaling after impeller exchange.

[Cooler]

I know I am over thinking this, but 1 more piece of info from my learning the hard way. If that single season impeller failed, find the reason for that. Are you replacing the impellers, or are you having a mechanic do it? You may want to check to make sure the impeller is being installed with the correct spin direction. The fins need to be squeezed & lubricated to fit into the housing. There are a number of vessels that do not have counter rotating engines. If the impeller is being installed assuming a LH rotation, but the engine is actually RH rotation, then the impeller is backwards to start, and will fail in short order as it is trying to correct in the housing. That can range from total disintegration to weak suction only. How much hotter is that engine running? Does it top out at a certain temp, or do you get to 200+?

[Cooler]

Last but not least - did not mean to ignore your question on HE removal, but I did. The exhaust hose connected to the exhaust elbow will have a sealant/adhesive on the inside of the hose, making it almost impossible to remove. It is possible, but really a tough job. I also found that out while replacing the upper exhaust flapper section. Never did get the hose off. Good luck. Keep us informed. We are all sitting on the edge of our seats! ( Winter, nothin' else to do )