Replaced the impeller and belt, now I have zero oil pressure?!?!

[sooner25]

Thanks for all the great info for changing the impeller and belt in the earlier threads! The impeller wasn't that bad, but it definitely had some cracks in the vanes. Well, yesterday, I took the boat out for the first time after the change. I got it in the water and was watching the temperature gauge. That stayed at at a normal level (170), but I noticed the oil pressure gauge was just sitting on zero. It was like something was unplugged. I immediately pulled the boat out of the water, just to be safe. Any ideas on what could have happened? Could I have unplugged the sensor or something? The boats an '01 2100V. Thanks again guys!

[scoot18]

From the way you have describe the situation it sounds like the boat was running for several minutes, as you were watching the engine temp. Feel confident in knowing that if you didn't have any oil pressure you wouldn't have made it that long. If you had zero oil pressure the engine would have only ran for a very short period of time before it seized. I am also sure that there would have been some audible noise for you to hear as well. From the way it sounds you probably have knocked a connector loose, probably at the sending unit. Not exactly sure, but if it ran several minutes you are ok.

How long was the engine running?

Were there any noise, knocking, ticking?

[sooner25]

From the way you have describe the situation it sounds like the boat was running for several minutes, as you were watching the engine temp. Feel confident in knowing that if you didn't have any oil pressure you wouldn't have made it that long. If you had zero oil pressure the engine would have only ran for a very short period of time before it seized. I am also sure that there would have been some audible noise for you to hear as well. From the way it sounds you probably have knocked a connector loose, probably at the sending unit. Not exactly sure, but if it ran several minutes you are ok.

How long was the engine running?

Were there any noise, knocking, ticking?

Yeah, it was running for several minutes. I know I didn't actually have zero oil pressure, because like you said, it would have seized up very quickly. I've had a built motor seize up in a Z28 I used to have. Its definitely something I won't forget! I just don't like not knowing exactly what pressure I'm running in case something did happen. Do you have any idea where the sending unit is actually located?

[R&T Babich]

On our 2000 21V 350 Mag MPI the oil pressure sender is mounted on the lower left rear side of the block. It's 2-3 inches long, maybe 2 inches in diameter, sorta looks like a bell. The connector on the top center is a 90 deg angled black rubber push on sleeve on the end of the wire - very easy to knock off or just loosen up inside. The sender has a 10/32 threaded shaft so I replaced the connector on ours with a ring eye, washer, lockwasher and nut. I've had those connectors loosen and/or fall off before.

[Jim_B]

My sending unit is right next to the raw water inlet hose and when I pulled my pump last month to replace my impeller I broke the connecter end off the wire for my sending unit.