Jittery Oil Pressure Gauge @ Idle

[slamkeys]

What causes the oil pressure gauge to jitter around at idle? My Yukon has about 95K miles and the oil and filter only have about 2K miles on them (mobil 1 synth).

 

The gauge smooths out once I start driving. My idle rpms look like they're around 500 @ idle (looking at the built-in rpm gauge).

 

Can this be caused by overfilling the oil? I haven't checked the oil level since I noticed the gauge issue, but I know I filled it to the max line the last time I changed the oil because I was using a 1 gallon oil jug and got carried away.

[PunchT37]

Mine is doing the same thing.

I`m going to change the sending unit.

[slamkeys]

Let me know if that fixes it.

[guido163]

Let me know if that fixes it.

 

 

Did this fix it??? Mines doing the same thing....

[slamkeys]

Let me know if that fixes it.

 

 

Did this fix it??? Mines doing the same thing....

 

 

It's been a while since I posted this, but I procrastinated on the fix and wanted to complete this thread for the benefit of others.

 

I just replaced my sending unit over the weekend and it works perfectly now. The pressure is actually showing about 5-8 lbs higher than it was before (the old unit was obviously wrong - read on), and it's as steady as can be.

 

I bought a special deep socket for $9.95 to help with the job, because the sending unit is in the back of the engine behind the intake manifold, so you can't even see it really - you have to feel for it. After I pulled the connector off, I was able to slip the socket over the unit and remove it easily with the aid of a 1/2" swivel and a couple of 1/2" x 12" extension bars.

 

Not surprisingly, the unit was visibly defective when I got it out and inspected it. The sending unit looks kind of like a spark plug at the bottom (metal), and has a black plastic cylinder on the top portion, which terminates with a female connector hub. The black plastic portion was almost completely detached from the bottom piece, and was only hanging on by about 1/4 of the perimeter of the piece.

 

My shop quoted this job at 0.4 hours, and if you have the right socket you can literally do this in about 2 minutes.

 

Total cost: $55.00

- Sending Unit: $45.00

- Sending Unit Deep Socket: $10.00

 

[burnthefurniture]

If you have the ability to get in there and do it yourself, its honestly a really easy job. You have to, however, have relatively small hands and be able to feel everything thats going on. I had to do this about 6 months ago with mine. I was getting on the interstate with a trailer, and got on the gas pretty good, and next time I looked down, my oil pressure was pegged on 80 and wouldn't move down. Talk about nervous. Turns out my sending unit had some oil that leaked into it and corrupted the sensor.

 

Back to the OP, I know mine fluctuates slightly at idle, which i always attributed to the little bit of rough idle that these trucks are known for. Unless its a significant difference, I wouldn't worry too much about it IMO.