2006 340 8.1 water pressure

[sejensen737]

Port raw water pump bearings failed. Rebuilt with mercruiser bearing and shaft and seal kit. New impeller.
Port water pressure at idle 1.0 psi
Stbd 2.6 psi

Port at 1000 rpm 1.8 psi
Stbd 4.8 psi

Port at 1500 rpm 5.2 psi
Stbd 8.6 psi

Coolant temp once stabilised 160 degrees both engines through rev ranges.

Do I have a pressure sensor problem or a worn out raw water pump casing? Pumps have 300 hrs on them.

Additionally , where the heck are the water pressure sensors? They are not on the pumps.

 

[Espos4]

350 MAGS have them on the P/S cooler. Maybe Yours is similar?

check with the mercury parts manual. Probably easier to swap sensors between Motors first to see if the pressures move too.

 

[Brite Idea]

i have the same situation port water pressure is half what the starboard is and no change after new impeller. I asked my mechanic and he said not to let it drive me crazy because the sensors are unreliable. I said what just ignore it? He said as long as it has enough pressure not to cause an alarm yes ignore it. So far it has been that way all season.

 

[Jimmy Buoy]

And if your pump housing is scored enough to create a water pressure problem, there is a kit available which incorporates stainless wear plates and a slightly shorter impeller which is a better solution than getting a new pump.