Mep802 pegged oil pressure gauge

[dstang97]

So my oil pressure gauge has been pegged on my mep802a. I believe it’s pegged because of the sending unit and not the gauge. I’m guessing it’s the round sensor that looks like a regular old Chevy 350 one. Any one have any leads on these? The ones online are crazy priced from GMG. Has anyone converted the numbers to a auto one?

 

[csheath]

Was a recent problem on a member's 803 and it had a stuck oil pressure relief valve.

 

[Guyfang]

You need to test the set for what the pressure IS, and not what you THINK it is. Could be the gage is right.

 

[dstang97]

The needle will not return to 0. Just stays pegged. I replaced the guage that had a needle at 0 and the machine pegged that one too. Where is this valve?

 

[jamawieb]

Test the sending unit per the TM. The oil pressure relief valve is located on the oil pump and you have to take the side cover off the motor to access it. I would bet that its the sending unit since you changed the gauge and had the same result. Also, if the oil pressure relief valve was giving to much pressure, the motor would not start because it would put to much pressure on the lifters, in turn opening the valves so it could not build pressure to start.

 

[dstang97]

I looked briefly at the manuals yesterday. It’s pretty tough reading them on an iPhone. Wish I still had my computer.

 

[kloppk]

... Has anyone converted the numbers to a auto one?

Did some googling and it looks like a Stewart Warner 279-A would work. $38
https://www.summitracing.com/parts/sww-279a/overview/

 

[dstang97]

Bought a new oil pressure sending unit from amazon. Works perfect now.

 

[jamawieb]

Which model did you buy?

 

[dstang97]

Which model did you buy?

https://www.amazon.com/gp/product/B000FQ79JO/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

 

[Daybreak]

Howdy,
It looks like the unit he purchased is a Sierra 18-5899 Oil Pressure Sender.

 

[dstang97]

Howdy,
It looks like the unit he purchased is a Sierra 18-5899 Oil Pressure Sender.

Yes sir

 

[millerm13]

You said you replaced the gauge, which one did you replace it with?
My gauge is pegged also on my 803a. Checking the sending unit per the TM and it is fine.
I think my gauge is shorted. Looking for a replacement.

 

[dstang97]

You said you replaced the gauge, which one did you replace it with?
My gauge is pegged also on my 803a. Checking the sending unit per the TM and it is fine.
I think my gauge is shorted. Looking for a replacement.

Got it from jim Henry. Parts unit. You can also match the ohms and find a gauge that will work.

 

[Guyfang]

You said you replaced the gauge, which one did you replace it with?
My gauge is pegged also on my 803a. Checking the sending unit per the TM and it is fine.
I think my gauge is shorted. Looking for a replacement.

Have you checked the wiring at the gauge. The gauges are often miswired.

 

[millerm13]

I have, it was previously working fine.
Just started it up the other day and it pegged to the right.
I am going to follow the TM on testing the gauge next.

 

[Zed254]

For Oil Pressure Gauge my notes say: Datcon - Oil Pressure Gauge 0-80 PSI 24V - 101574. Look on Ebay for "DATCON 2" PRESSURE GAUGE PART NUMBER 101575" to find something close. However, this one has shiny bezel. 240 ohm resistance matches above referenced oil sender unit.

 

[DieselAddict]

The first thing I do when presented with a pegged pressure gauge is to use a known good mechanical gauge to verify that the condition the electrical gauge is reading isn't true. Its likely if the oil pressure is pegged out that the lifters will pump up so much to float the valves but that aside I consider it important to have a secondary confirmation of a reading.

 

[Guyfang]

The first thing I do when presented with a pegged pressure gauge is to use a known good mechanical gauge to verify that the condition the electrical gauge is reading isn't true. Its likely if the oil pressure is pegged out that the lifters will pump up so much to float the valves but that aside I consider it important to have a secondary confirmation of a reading.

Roger, roger, roger!! Find the real problem, fix it. Throwing parts at a gen set will fix it, if your pockets are deep enough. But easyer, cheaper, is proper troubleshooting.

 

[millerm13]

Purchased new oil pressure gauge and installed it. Back up and running. Works perfect. Thanks everyone for the advice.