I own a 2007 GMC Enovy. The oil pressure gauge is showing symptoms of a bad sending unit. I am confused about the location of the oil pressure sending unit. Some diagrams seem to show it on top of the engine in the rear under the intake manifold. Other diagrams show it by the oil filter. Can someone tell me which location is correct? I would like to repair this problem myself. Thank you in advance for your help.
Oil pressure sensor
- Thread starter mlan12
- Start date
AtlWrk
Member
- Dec 6, 2011
- 674
Depends on the engine. The oil pressure switch on the 4.2L six cylinder engine is by the oil filter. The 5.3L V8 engines have their sensor on the top of the engine near the back. Your profile says you have the 4.2L so it will be right next to the oil filter, very easy to get to 
Thank you all for your answers. Really is very much appreciated. This forum is another reason to be very happy with our Envoy.Thanks again.
Mooseman
Moderator
Oil pressure gauge is fake. The readings are fabricated by the PCM. If there was an actual problem with oil pressure or the pressure switch, you would get a message on your DIC. If no message, then it's the stepper motor in the gauge. I wouldn't bother with it since it is of no use.
mcsteven
Member
- Apr 18, 2012
- 6,584
Mooseman typed it before I saw this thread. If you have the 4.2 L it is not an oil pressure gauge but more of just a monitor. If your oil pressure goes above (I believe it is) 12 psi then it will read about 40 or just over 40. As Mooseman stated, it is controlled by the PCM. They even added extra programming so that if you are not in gear and revved the motor the needle will fluctuate. If it drops below 12 psi your oil light will ignite and if you have a driver information center (I think all the envoys had that) will tell you to shut down the motor.
Do you have an android device with Bluetooth? There are some inexpensive readers and an app for five or six dollars and you can monitor A lot of items, including, I believe, oil pressure. The device, referred to as ELM 327, plugs into your OBD-II port. The app has a lot of features beyond gauge readings. I can't think of what the app is called but I'm certain others do or if you PM me I will take a look at my android tablet for you.
EDIT: if you drive aggressively or on a lot of hills you might consider an oil pick up tube extension/relocation or putting slightly more oil into it. The oil pick up is at the back of the oil pan and if you are hitting the brakes a lot or running downhill a lot it might give you problems.
Do you have an android device with Bluetooth? There are some inexpensive readers and an app for five or six dollars and you can monitor A lot of items, including, I believe, oil pressure. The device, referred to as ELM 327, plugs into your OBD-II port. The app has a lot of features beyond gauge readings. I can't think of what the app is called but I'm certain others do or if you PM me I will take a look at my android tablet for you.
EDIT: if you drive aggressively or on a lot of hills you might consider an oil pick up tube extension/relocation or putting slightly more oil into it. The oil pick up is at the back of the oil pan and if you are hitting the brakes a lot or running downhill a lot it might give you problems.
I dont want to hijack this thread... but this afternoon my oil pressure went to zero, a msg on the dash lit up saying "check gages" ... later it also said low oil pressure on the dic. Please tell me something else is wrong other than a real issue with oil pressure!! (oh and thanks in advance)
freddyboy61
Member
- Dec 4, 2011
- 276
gmc4flash, you need to check your oil level for of all, if it is up to the full mark, then I would suspect the oil pressure sensor is bad. Short of attaching a mechanical gauge to the engine, I would change the sensor.
Wooluf1952
Member
ok so I checked the oil, it was maybe 3/4's of a qt low so I put a qt in. I guess I need to look to see if the sending unit is leaking or has signs that is it going as well?
yeah. oil in the connector is a giveaway. On mine, the gauge would go to zero, then occasionally bounce back to normal. Mine is an LS that doesn't have the DIC.
the part is fairly cheap and easy to replace. just don't do like I did and rip the gasket on the new one...will leak big time then! I had forgotten to put a little bit of oil on the gasket prior to installing it.
the part is fairly cheap and easy to replace. just don't do like I did and rip the gasket on the new one...will leak big time then! I had forgotten to put a little bit of oil on the gasket prior to installing it.
I sat an watched my oil pressure bounce around like a ping pong ball... the whole time a slight increase in rpms would calm it down. I will go pick up a new one and hopefully the issue will go away.
replaced my oil pressure sending unit last night... what a pita for such a trivial task... after getting it out, the connector was definitly leaking oil... anyway hoping this resolves that.
I would attach a mechanical oil pressure gauge and check. Continually running or starting an engine with little or no oil pressure trying to diagnose an issue can lead to expensive repairs.
Tiggerr
Member
02blackenvoy
Member
- Feb 1, 2014
- 79
Yep, Mine did the same thing the other day... Pulling away from the house got the 0 oil pressure and the stop engine on the DIC. shut off, restarted, and it was ok for a few minutes, then it did it again. After work, I replaced the sensor, and when I pulled the plug, oil came out. Easy fix, and the issue is gone. A 1 1/16 socket is needed or the proper oil pressure sender socket (which I was lucky to have) and it took about 15 min total. To be honest, it took longer to put it on the ramps than it did to do the job...lolsunliner said:
Yep fixed mine, I drove it for 2 weeks and now my Son has driven it since then. (at least I hope he would notice if it went back to 0 
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