Intermittent Water Pressure at Gauge

[Jud Hamblett]

Motor is a 2002, Mercury 115, EFI four stroke. 225 hours. Water pump replaced at 100 hours. Water pressure gauge shows zero pressure or barely moves. Removed Gauge water tube from block. No water coming out gauge fitting at the block at idle or even 3,000 rpm.<br /><br />However, telltale give steady stream and good water flow from large water tube leading from T Stat to side of block. Head feels cool all over, and no alarms sound. Reconnected gauge tube at block and disconnected tube at the gauge and ran motor. After 30 minutes or so of running steady warm water stream comes out at guage tube end. Reconnected tube to guage - all is fine – water pressure at 5,000 up to 23 pounds, idle around 5-10. <br /><br />Two weeks later same routine – no pressure indication at gauge (no water column reaching gauge) , no water pressure coming out of the block at gauge tube attachment point. Then after running a good hour, warm water squirts out of gauge tube. Reconnected gauge tube, and all is fine. <br /><br />No idea why what is causing the problem…help please.

 

[WillyBWright]

Re: Intermittent Water Pressure at Gauge

Has this been acting this way for a long time? Have you always had the gauge? It almost doesn't sound like the motor is the source of the problem. If that pee indicator is showing a good stream, then the gauge should get some sort of reading. Could be an internal blockage that comes and goes, but I'm thinking kinked hose coming out of the motor. Check the pressure gauge line all the way from end to end, especially where the "umbillicals" move around.

 

[Jud Hamblett]

Re: Intermittent Water Pressure at Gauge

Will…thanks…..yes there is a strong stream and I’ve had the gauge for some time. Problem started after motor was not run for about 8 weeks. Earlier I did disconnect the gauge tube from the engine and nothing came out of the hole on the engine. Yesterday I pulled off the poppet valve cover and cleaned the spring and plastic valve seat. From what I can tell the water galleries to the gauge connection fitting on the block and poppet valve area are connected. I have gauge pressure now and will be making a run to across the Gibraltar Strait this weekend….will see how it goes. Rota forecast looks good.