Mercruiser 6.2 showing high water pressure

[Srafie24]

My mercruiser 6.2 on a Monterey 33 is showing high water pressure sensor going off I have changed the water pressure sensor I have changed the impeller My water pressure is still showing very high over 40 and 3k rpm. The engine is not over heating but yet the sensor alarm is going off . I'm going nuts

 

[alldodge]

Might have a restriction somewhere or it could be the poppet valve

What is your serial number?
You in fresh or salt?

 

[Srafie24]

Im.in fresh water
I dont have my serial number

 

[alldodge]

The serial number is on the motor
If not on top of the cover, look above the starter. The issue is there have been all kinds of changes to the 6.2 over the years. We need to know how yours was built

 

[QBhoy]

My mercruiser 6.2 on a Monterey 33 is showing high water pressure sensor going off I have changed the water pressure sensor I have changed the impeller My water pressure is still showing very high over 40 and 3k rpm. The engine is not over heating but yet the sensor alarm is going off . I'm going nuts

Did she overheat previously? Perhaps enough to have a flapper stuck down the exhaust and restricting flow ?

 

[Srafie24]

Did she overheat previously? Perhaps enough to have a flapper stuck down the exhaust and restricting flow ?

She did over heat previous

 

[chopper_bob]

I’m having similar issue with my Monterey 244FS, 350 Merc. I am showing 20-40 block pressure psi at idle and 110-140 at cruise all of a sudden. Temp and oil pressure is fine. No overheating, accelerates fine, no misfires. Guardian mode keeps kicking in. Changed impeller and poppet valve last summer and it ran great until last week.
Any ideas on why block pressure is so high???

 

[Srafie24]

So I just changed the water pressure sensor and the pressure it still high but it's not beeping anymore and putting in protection mode.

 

[alldodge]

My thought on water pressure sensors, they vacuum (so to speak)
There is no reason what so ever to have one other then to cause problems with anything other then "maybe" a CAT motor

If my temp was running good, and so long as there is not issue(s) with the ECM throwing codes. Leave the sensor alone. High is better then low. When it goes low "you have to fix it".

 

[QBhoy]

So I just changed the water pressure sensor and the pressure it still high but it's not beeping anymore and putting in protection mode.

I think now we know it’s overheated before...I’d be looking to see if there are bits of exhaust flappers stuck down the exhaust and restricting flow.

 

[bruceb58]

What year is this engine?

Smartcraft sensor?

Really hard to believe that an exhaust flapper would be causing a water pressure issue without causing WAY more other issues like overheating and/or poor engine performance.