4.3 hot at idle and slow speeds

[jcblizz]

Recently my 4.3 will start to get hot at idle and slow speeds in the water but as soon as you take off it cool right back down. water pump? thermostat?

 

[frank246]

Re: 4.3 hot at idle and slow speeds

Why dont you just replace both, id start with a pump house and impeller check.

 

[Bondo]

Re: 4.3 hot at idle and slow speeds

Ayuh,... In Any Overheat situation, the Impeller is the 1st place to Look....

 

[jcblizz]

Re: 4.3 hot at idle and slow speeds

ok. not real savy about the cooling system on these things. i have heard of and impeller but not exactly sure where that would be located. i thought that the water pump did the work.

 

[TiredoleBoy]

Re: 4.3 hot at idle and slow speeds

Ayuh,... In Any Overheat situation, the Impeller is the 1st place to Look....

THis

 

[Bondo]

Re: 4.3 hot at idle and slow speeds

i have heard of and impeller but not exactly sure where that would be located. i thought that the water pump did the work.

Ayuh,... The Raw water pump is located at the top of the Lower unit,...
The Circulating pump is on the front of the motor, it Rarely goes Bad...

 

[TiredoleBoy]

Re: 4.3 hot at idle and slow speeds

ok. not real savy about the cooling system on these things. i have heard of and impeller but not exactly sure where that would be located. i thought that the water pump did the work.

Depending on the system. EG: I have a closed system but the out drive and antifreeze is still cooled by sea water. Thus an impeller. Some systems are cooled solely by an impeller in the out drive.

 

[jcblizz]

Re: 4.3 hot at idle and slow speeds

well i thought impeller also but like yesterday. i trolled about 200yds into the marina then let it sit and idle at the pump for about 5 mins while i got the trailer in the water to put it on and it never got hot. lost???

 

[jcblizz]

Re: 4.3 hot at idle and slow speeds

took the boat out again today and no troubles. I dont know what to think. could the thermostat be getting stuck sometimes?

 

[achris]

Re: 4.3 hot at idle and slow speeds

When was it last serviced?

If you do a lot of running in shallow water you could easily have a worn impeller (sand is very abrasive).

Chris......