Crazyaces69

Hey Guys,

I have a 1996 Jeep Cherokee 4.0. I replaced my instrument cluster because I did not like the Oil & Temp light. I went and purchased a new cluster w/ gauges. I also purchased brand new sending units for both oil and temp gauges. So, here is the problem.

when the key is in the on position the Oil Gauge shows 0.
when I start the Jeep the Oil Gauge shoots right to 80.

So, I traced the line from the Oil Sending unit and it seems to be ok.

As of now, I have changed the oil and filter and used a Fram filter and 5w30 oil, only because the idiot that had the jeep before me used diesel oil to clean out the unit. I'll change again using a Mobile 1 Filter, w/ 10w-30.

The Jeep has 162210 miles.

stockli

Diesel oil of the right viscosity is fine, and preferred by many in there 4.0.

Dont ever use fram filters, they have a wonky back flow valve.

Did you get the right sending unit?

Does the oil pressure drop back down after start up or stay pegged at 80?

Crazyaces69

yes on the sending, but its a cheep one: its a BWD S4131.

Understood on the fram filter, I will change it.

and on the sending unit, no. It stays pegged at 80 and will not move until I shut it down. It only reads 0 when its in the on postition.

nothing else. just 0 to 80 each time. and Its been this way for roughly 35 miles

89Laredo

That is a switch not a sending unit...
Get a sending unit and your gauge will magically work again...

xjpioneer

X2 checker gave me a switch instead of a sender once.. Did the same thing. Instead of sending a varied signal, like the sender does... the switch will send a constant value saying that the pressure is above a pre-determined value.

Crazyaces69

TY Guys,

I looked at the BWD part numbers, and like you stated it was a switch, so, i brought it back to O'Reilys and swapped it for a MasterPro 2-8113. Paid 18.23 more but worth it. I placed the key in, turned it to the on position and of course it dropped to 0 like the other one, but as soon as I started the Jeep it raised to only 71 out of 80. So, next Ill replace the oil filter "Fram" to another brand. Which is a decent filter for a 4.0 cherokee? I figure a Mobile 1 or something else. Hopefully than I'll get the reading between 40-60.

89Laredo

Mopar m-090 is good, its a rebranded wix. Wix filters are good, Napa is the same, just rebranded.
Purolator.
Bosch.
Motorcraft FL1-a if you want an oversize.

War Eagle

this

xjpioneer

Or to be absolutely sure..
You can get the oil pressure reading from a mechanical gauge. Those things are cheap.