H20 gauge shows 0 psi
 

my h20 gauge shows o psi on my system view and on gauge no buzzer engine runns perfect any idea what it can be ? by the way this is a merc 6.2 mpi 2004 also have another problem when running the motor out of the water on ears water seems to come out between the leg and the upper part where it bolts on

Is it a mechanical or electrical sensor/sender? If electronic check electrical hookups, if mechanical check tubing for blockage.

Thru prop exhaust? There are 2 exhaust outlets at bottom of transom shield that shoot water out. Straight thru-hull, no y-pipe, you should see no water there. Water pressure. If you have 0 psi you will also have 0 gal/minute flow. If you pull a hose or sender and water sprays out, gauge or sender is lying to you.

very common - water pressure sensor and or debris in it. Also worn impeller and or housing, Also sometimes can be an off reading as OEM Merc for the this 1 psi and up at dead idle.

So what happens to the reading bumping throttle up very slower past idle rpms and up ?

just adding info it is NOT a mechanical psi reading. Its a sensor just like an oil pressure sensor - in which that sensor inputs to the ECM 555 and the ECM outputs to the smartcraft gauge if applicable and the scan tool when adapted to the DLC for engine scanning .

One can test water psi readings with a hand held mechanical gauge just like as if you were pulling the oil pressure sender out and testing oil pressure with a mechanical gauge.

Off topic.....

you must want to send money to me haha

or would be an issue with your twin Volvo s in your Cobalt ? haha again