TAMD40A Overheating

"1:TAMD40A would overheat when

"1:TAMD40A would overheat when over 2000 rpm.
2amper plate broke and replaced.
3:Engine tested when boat hauled out, ok.
4 n trip from yard raw water impeller stripped and engine overheated.
5:Impeller replaced and raw water inlet cleared (bottom paint).
6:Engine still overheating at idle.
7:Cooling element taken out shop cleaned and checked and replaced.
8:Engine still overheating at idle.
9:Thermostats taken out and tested opening and closing.
10:Engine still overheating at idle.
11:Circulation pump appears to be working.

Any ideas as to what I should look at next ?"

"Is it overheating above 2000

"Is it overheating above 2000 rpm or overheating at idle?

Is it really overheating or could the sender or gauge be defective?

Did the old impeller come apart and if so, did you recover all the pieces?"

"Initially it was overheating

"Initially it was overheating above 2000rpm.

Then after the haul out, it overheats at idle.

Yes, the old impeller came apart.

Yes, all the pieces that could be found were removed from the raw water system."

"I had a similar experience wi

"I had a similar experience with a TAMD 40B where the impeller fragmented. I am sure you have remaining impeller shards blocking your water flow - probably on the intake side of the pump which is where mine occured. I had focused my attention on clearing broken bits of the impeller from the pump thru the heat exchanger (the direction of force of pumped water), but continued to get overheating over 2500 rpm. Evenutally, I found large chunks had dropped down (gravity) into the intake pipe (the other direction) and settled between the intake valve and the pump. When the engine started they were sucked up against the grid at the water pump restricting flow just enough to have an effect at higher rpm. When the engine was shut off, the lack of "suction" would allow the pieces to drop back down the pipe so a check of the water pump would show nothing.
Good Luck. Let us know what you found."