bassmaster59
Regular Contributor
I replaced the water pump kit on a buddies 2008 mercury 150 dfi because he said the pressure had dropped since he bought the motor new. He stated the pressure was 8 to 10 lbs. at idle & 15 to 17 lbs. at wot when the motor was new. Now the pressure reads 2 to 3 lbs. at idle, and 8 to 10 lbs. at higher rpms. We had muffs on it after the impeller change, and the pressure is still 2 to 3 lbs. and 8 to 10 lbs respectively. I accelerated the engine a time or two very briefly and the pressure went up to 10 then dropped back to about 6 lbs. The water is peeing with a good stream at idle and increases when accelerated. No heat alarms or nothing out of wack I can tell. Is it normal for a new engine to have that much pressure then drop like this has done? Is there any other valves or parts I need to check that might be clogged? Thanks guys
