New water pump, and motor still running hot?

[mdlee]

I have twin 190 mercruisers. The port side motor has been running hotter than the starboard motor. I replaced the water pump in the port side motor, pulled the ends off the heat exchanger and found rubber chunks form the old impeller. Upon finding the trash in the heat exchanger, I pulled all the hoses off the raw water system, and flushed them as well. I took the riser off and flowed water through it using a water hose,, it seemed to flow fine. But the motor is still running at about 190-200F. The water flowing out of the transom plate is very hot, and not a good steady flow. I spoke with a local mechanic and he thought the problem might be the hose running from the lower unit into the transom plate?? I trimmed the drive up and ran my had along the hose, and it does not seem to be crimped. What do you fellas think?

 

[Don S]

Re: New water pump, and motor still running hot?

I replaced the water pump in the port side motor,

What about the water pump in the outdrive, that is the one that has the rubber impeller.

 

[mdlee]

Re: New water pump, and motor still running hot?

The pump in the lower unit is the one I replaced. It will pump fine for a min and then it will just spit for a min or 2,, and start pumping OK again. Is seems like it is having trouble picking the water up, or getting the water out?

 

[Don S]

Re: New water pump, and motor still running hot?

What did the upper and lower housing look like? Did you replace the gaskets. You wouldn't believe some of the warped and overheated housings I have seen after the owner replaced the impeller only.

 

[mdlee]

Re: New water pump, and motor still running hot?

I used a kit with housing gaskets the whole works... It is strange,, I am stumped by this thing. Do you think it is likely that the hose running from the lower unit to the transom may have any thing to do with it.

 

[Eric 3.7LX Alpha 1]

Re: New water pump, and motor still running hot?

I don't have your engine so I am not sure, but can you disconnect the hose inside the engine compartment coming from the drive thru the transom and with muffs on see how flow is? Engine on or off to see if there is an obstruction in that line?

 

[Don S]

Re: New water pump, and motor still running hot?

Are you sure the engine is actually running hotter, and not just a bad sending unit making it look that way?
Might want to really look at that tube that goes through the transom shield, The sharp bend is a place that big things like to hang up.

 

[mdlee]

Re: New water pump, and motor still running hot?

That is a good idea removing the hose and looking to see if the water is coming through the tube inside the engine compartment............ And I will take a look at the hose coming from the lower unit. Will I have to remove the drive unit to remove that hose?