Oil pressure reading max all the time - even when engine isn't running

[dhardest]

Hello, I have a Volvo Penta 5.0 GXI-G and the oil pressure gauge reads max pressure all the time. The gauge max dial reading is 80 psi and when I turn the ignition to "on" so the accessories and gauges have power (without starting the engine), the dial pegs all the way past the 80 psi reading. I cleaned and tightened the connections on the back of the gauge in case that was contributing to the issue but problem persists. I suspect some sort of short or maybe a bad oil pressure sensor, maybe bad gauge, but was looking for confirmation or other possible ideas as to what could be the issue.

Thanks,
Dennis

 

[Bondo]

Ayuh,.... At the oil pressure sender, remove the wire,...
With the key "On", the gauge should read 0, then touch the sender wire to ground, the gauge should peg to high,...
If so, replace the sender,...

 

[dhardest]

Thanks ..... I'll try this today and will report back ..... appreciate the helpful tip.

 

[dhardest]

Hey need to follow up. I'm thinking the oil pressure sensor on this engine is different than on some others. I've heard that on some engines there is an oil pressure sensor that has a single wire. And perhaps this is different than an oil pressure switch. But when I look up the part for my engine (2007 5.0 XI-G), the parts diagram points me to this part (part 19 in the pic below). This sensor is located immediately above the location where the oil filter would be (although I have a remote oil filter). This sensor has a connector with three wires leading to it.. With ignition in on (engine not running), pressure reads max > 80 psi. Unplug the connector and the pressure gauge briefly flickers to zero then pegs back at max.

Does this tell us anything? Sensor bad, or is it the wiring (a short)? A possible related fact ....... I've suspected for a while that I may have a short someplace in my wiring since if I leave my battery in the boat overnight, the battery needs charged after one or two nights.

Thanks again for the help.
Dennis

 

[dhardest]

OK, a bit more info. I may be getting closer to the problem. I noticed that the 3-wire connector when connected to the sensor doesn't seem to be a snug fit. I'm able to wiggle it and there is some play both in/out as well as able to twist the connector a little clockwise and counterclockwise. When I do I'm noticing that the oil pressure gauge is bouncing around. When twisted counterclockwise to the left and I hold, the gauge reads zero pressure. If I let go, the gauge goes back to 80 psi. I'm not sure if this is the fault of the sensor or the connector on the wires. But I definitely suspect that the fact this connector isn't making a solid consistent connection is the issue.

 

[Bondo]

I'm not sure if this is the fault of the sensor or the connector on the wires. But I definitely suspect that the fact this connector isn't making a solid consistent connection is the issue.

Ayuh,.... Sounds like ya found the problem,...

I can't see, nor feel it, so yer gonna have to figure out whether it's the connector, or sender,....

 

[dhardest]

Confirmed it's the connector on the wiring. Determined this by buying a matching connector for $16.99 at autozone (Autozone part 417 online, it's a multi-purpose connector used for several sensors that have the same connector style). I plugged in the new connector that came with a 3-wire pigtail (and includes the rubber boot to make sure it's water tight) and then just to make sure this would fix the problem, I inserted the end of each pigtail wire into the appropriate terminal of the old connector still attached to the wiring harness. The oil pressure gauge read 0 psi and was steady. So now I'll go ahead and cut the old connector off and splice this new connector onto the harness, and use heat shrink tubing to make sure the splice is water tight. Glad to get this resolved so can have peace of mind that I'm getting a good reading on the gauge.

Here's the link to the connector I bought. Fairly cheap fix ..... was considering buying a new pressure sensor for about $75 just to rule that out.

http://www.autozone.com/cooling-hea...oolant-level-sensor-connector/349715_923441_0