2008 Mercury 90HP four stroke overheating.
Posted: Mon Jun 23, 2025 10:16 am
Okay, based on what I have researched, I think I need a cooling impeller. However, I want to post my symptoms to see if everything still points to the cooling impellar.
At startup and at idle.
-There is possibly a delay before the water starts to come out the pee-hole after started.
- When it is peeing, the stream is very erratic and not consistent like it used to be.
-If allowed to idle for a few minutes, the engine power is drastically reduced if you throttle up, and most of the time, I get 6 beeps.
At WOT:
-The cooling pressure gauge is erratic and averages around "10 o, o'clock", but bounces around quite a bit. Normally, its averaging around "12-1 o'clock", and remains fairly solid.
-When I throttle down, I will likely get six beeps.
I'm reluctant to think there is a cooling system clog. My lake is very clean. The engine has the original cooling impeller from 2008.
Question. Does the impeller play a role in cooling at WOT? Or, does the velocity of the water entering the cooling intake at WOT provide the bulk of the water pressure? If the impeller does play a major role at WOT, I'm now further convinced it needs a new one.
If I do need a new impeller, should I go with an OEM unit, or will a cheaper one from Amazon go the distance?
Thanks
Bill
At startup and at idle.
-There is possibly a delay before the water starts to come out the pee-hole after started.
- When it is peeing, the stream is very erratic and not consistent like it used to be.
-If allowed to idle for a few minutes, the engine power is drastically reduced if you throttle up, and most of the time, I get 6 beeps.
At WOT:
-The cooling pressure gauge is erratic and averages around "10 o, o'clock", but bounces around quite a bit. Normally, its averaging around "12-1 o'clock", and remains fairly solid.
-When I throttle down, I will likely get six beeps.
I'm reluctant to think there is a cooling system clog. My lake is very clean. The engine has the original cooling impeller from 2008.
Question. Does the impeller play a role in cooling at WOT? Or, does the velocity of the water entering the cooling intake at WOT provide the bulk of the water pressure? If the impeller does play a major role at WOT, I'm now further convinced it needs a new one.
If I do need a new impeller, should I go with an OEM unit, or will a cheaper one from Amazon go the distance?
Thanks
Bill