I searched the forums but I could not find this answer. I noticed stbrd engine temp rising (by the way I have twin 496 ho 's with smartcraft hooked up thru northstar) I did bump a sandbar the day before so I assume I picked up sand, but after reading thru the forum most people say they lose sea water pump pressure but mine goes 20 psi higher and temp runs about 5-10 degrees higher. I have never had alarms or shutdown, I was going to pull the hose off of heat exchanger and backflush back to pump, any other advise? Thanks

Sounds like you had the impeller come apart and its now creating a restriction.

Sounds more like a blockage on the exit side of wherever the pressure gauge is mounted. Not letting the water escape, thus higher pressure and temps. Not necessarily a wiped out impellor. Just a thought.
Those that have lost pressure have usually wiped out an impellor or plugged up a cooler/strainer on the inlet side from where the press gauge is mounted.

ok first I'll check the impellor but where is pressure reading takin from. I assume the impellor would reduce water pressure.