Walter V-drive low oil pressure

I have a 2004 SV211 with the ZR6. It runs the Walther (edited) V-Drive.
Last fall it was running fine, I winterized it, changed all the oil (engine, trans, vdrive), etc.

I got it running on the hose, and then dropped it in today. After engine warmed up, I picked it up to 35 or so, everything felt great, looked down and the vDrive oil pressure light was still on. Slowed down/stop/pick up speed again, light stays constantly on (not even a flicker).

Checked the oil and it was on the low side (clean, but close to the L) added a bit more oil to get it up to the H side. Tried again, but same result.

So idled to my dock. I'm not sure how to check the sensor. The wires look corroded, and I can't even get the screws out without it starting to strip.

Based on another post from here, I pulled the sensor out and had my wife put her finger on the sensor hole, while I drove it a bit. I was only able to get to about 1500RPM as I am in a no-wake zone, but she said she felt no difference when I put in gear or throttled up, other than the sound. Her finger was still bone dry.

Is there a better way to test this? Should I just get a new sensor and try that? I'm worried that this points to a bad oil pump, which I have no idea if that is something I can attempt, or if I am looking at a couple grand back at a dealer.

Any ideas how to bench test the sensor? Or something else I should try?
If it is the pump, is this anything I can do, or does it take pulling the engine out?

It is such a nice day out here... really was wishing to social distance in the middle of the lake.

Doug

Here's a short little operating manual, check page 5 "operation" for some troubleshooting info

link

And here's a longer manual

link

DFoster wrote: Walter V-Drive... not sure how I did Wurth... but hey, rushing around. I managed to pull out the sensor. Hooked it up to the volt meter and my air compressor at 20 psi. Shows closed with no pressure and open with 20 psi. Compressor isn't accurate below that so not sure if that is too high, but I guess that means sensor is good. Or does anybody know the specs? I heard it opens between 2 and 4 psi. And the manual says normal pressure is 6 to 12 psi, so not really conclusive. One thing I noticed when reading the manual is that I don't pull the oil strainer out when doing oil changes. The oil looks super clean, as I am only doing about 30 hour per season right now, but not sure if something could get clogged in the strainer so that I can't build up pressure. I also tested the connection to the warning light. I'm able to get the light to turn on/off properly, so I know that the wiring is good. Or is at least good now. Any suggested next steps? Thinking I may need to drain the oil clean the strainer, etc. But is there any way to test out the mechanical pump? I don't think I have a gauge that reads 2 - 12 psi to test. Just more car pressure gauge, etc.

The parts like a gauge and fittings to test the pump wouldn't set you back 20 bucks and you'd know if your pump is putting out pressure. You could then turn around and use the same gauge to test the switch.

The light is on at less than 2 psi and goes off as you get slightly above 2 psi,

If your pump puts out the 6 to 12 they mention, the light would be off for sure. I'm not sure how much more conclusive you want.

You could get all the parts at Home Depot or a hardware store.................or pay big bucks to get it tested

Yes,good point. Will run out tomorrow and find a gauge and fittings that will work. Need to be sure what the issue is before I pull the boat and bring her to the dealer.
Thanks for the help.

So, the bad news... I got a mechanical gauge to test everything out. On the bench the sender opens properly at about 2 - 3 psi.

Hooked the gauge up instead of the sender on the V-drive, took it out for a spin. 0 psi at idle, 0 psi at 2500 rpm. Decided that was bad and put it back on the lift for now.

At the end of last year, I had run over some dock line that had fouled the prop and actually stalled the engine when in gear. Cut it off, and things seemed fine, and pulled the boat. I'm now thinking that that caused some issue with the V-Drive.

So, is the mechanical pump serviceable? Or are there any recommendations for someone that can service it in the MA/NH area? Pete @ MacCallums says they will just replace it, not service it.

We also rebuild Walter v-drives and Basic rebuilds start at $1,300 + oil pump Assy (obviously) but I will be able to save you a few bucks there cause I have a few pumps in stock. Give us a call 330-273-8291 names Joe