Low oil pressure mind boggled


Asked by Mar 07, 2016 at 12:47 AM about the 2006 GMC Yukon Denali AWD

Question type: Maintenance & Repair

10 Answers


Hello! Thank you guys for having me here! I'm a complete noob but still learning as much a I can. I own a 2006 yukon denali and my heart lies in this model. I'm having retarded issues with low oil pressure an I can't understand it for the life of me. I would greatly appreciate if somebody could point me in the right direction. The Car currently has 180k mileage done and I've slowly been restoring it. Everything has even running fine for the last 4 months of purchasing it. Inclusive of things I've changed. I've changed te solenoid valves, water pump, shock absorbers, done rust proofing, new tires / rims etc. After everything suddenly one day after all these months the oil pressure gauge dropped and the idiot light and warning tones came out full beeping. Only when I rev it goes back up but not to the 275 marker. Just to the quarter marker before it. (I'm assuming each marker is 37.5 psi?). Anyways I've now replace the oil pump, the oil pressure sensor and another oil switch all from AC Delco. There admit any knocking noise to what I keep reading. Engine runs quiet. Replace the gaskets, cleaned out the entire oil pan and from timing cover etc. Replaced the oil filter change the oil. Started the car up it jumps up to the first little marker and stays there. When I rev or drive normally it goes steady to 75psi the fat quarter marker. It only gives me this light and beeping noise when I sit idle in traffic or t a red light. It's so frustrating. I've to shift into neutral and keep revving. No matter what I've done everything is still the same. I've cleaned and replaced everything I can think of. Is it the oil I'm using? Ever since I did an oil change it went stupid. Do I have to replace my whole engine? I know high mileage engine pressure drop happens. Any suggestions? I would truly be grateful truly. Is It the oil filter?. I can't figure this out, even the mechanics are bogged and trying the same things. I love you guys!

1 of 1 people found this helpful.

There is no knocking or ticking noise whatsoever. Sorry for this autocorrect crap.


Is the oil pressure sending unit the same as oil pressure sensor? If I start up the car and sit idle it's completely fine sitting on the first marker, no stutters or engine noise nothing. This only happens when I idle in traffic after driving then everything goes apeshit in the car with te warning alarms and lights etc meh.

1 of 1 people found this helpful.

Are housing oil recommended for car, u should. Did u try compression test? Any codes showing?

Best Answer Mark helpful

Yes done the compression tests no codes. Thank you for responding Mik! I was getting worried there. I'll try again today at another garage for pressure check. Also when I turn the key to ON but not start the engine. All the gauges move. Except the oil pressure gauge. It just sits at 0


Housing oil? What is that? Sorry little sheepish I feel


At I ask is the oil pressure sending unit and the oil pressure sensor the same thing? So many confusing people saying yes and no to this. If it is then I replaced a sensor and a switch. If not then I'll get a search for a sending unit.

1 of 1 people found this helpful.



I meant using not housing, sorry. Compression test is test done seperate from codes, u know that right? Are cylinders reading correct pressure? When oil light goes on is rpm's dropping real low, ready to die low? If so could be idle control sensor. Go to rock auto.com and enter the sensors u have a question about, c if they come up different. They should b the same. Is your engine filled to correct oil level? Is the dipstick OK, not damaged and maybe giving u an off reading? Jus throwing ideas out there. Did u do something wen u changed the oil to cause it?


Oh wonderful!!! Yes I haven't got any codes and I'm not gettin any pressure issues from the test. I haven't had the light go of with all the driving I did today. Next time it drops I will be sure to check the rpm when light goes on to have a clear answer!. The oil level is filled correctly but I will check the dipstick and the oil level again just to be sure again for the enth time. All I did was change the oil and oil filter and when my DIC said oil health at 89% is when this happened. I'm using the correct that is written in the car manual. The oil filter also I've changed again and using the one for this specific model cause I opened it up and it wasn't dirty or trashed. Maybe it's the oil viscosity? But I think you're right it might be a sensor issue or an off reading. I will check and let you know thank you so much truly for the ideas I grately appreciate it.

1 of 1 people found this helpful.

Your Answer


Looking for a Used Yukon in your area?

CarGurus has 18,483 nationwide Yukon listings starting at $1,800.


GMC Yukon Experts

  • #1
  • #2
    David Boccabello
  • #3
View All

Related Models For Sale

Used Chevrolet Tahoe
625 Great Deals out of 37,366 listings starting at $795
Used Cadillac Escalade
250 Great Deals out of 11,801 listings starting at $2,995
Used GMC Yukon XL
216 Great Deals out of 12,544 listings starting at $2,700
Used Chevrolet Suburban
420 Great Deals out of 22,163 listings starting at $2,495
Used GMC Sierra 1500
881 Great Deals out of 58,809 listings starting at $1,980
Used Ford Expedition
435 Great Deals out of 19,800 listings starting at $2,500
Used GMC Acadia
572 Great Deals out of 38,004 listings starting at $3,500
Used Chevrolet Silverado 1500
2,171 Great Deals out of 149,980 listings starting at $1,499
Used Cadillac Escalade ESV
142 Great Deals out of 6,509 listings starting at $3,950
Used Ford F-150
2,486 Great Deals out of 219,880 listings starting at $1,222
Used Ford Explorer
835 Great Deals out of 63,811 listings starting at $600
Used Jeep Grand Cherokee
786 Great Deals out of 72,877 listings starting at $999
Used Dodge Durango
220 Great Deals out of 24,239 listings starting at $1,500
Used Toyota 4Runner
310 Great Deals out of 29,734 listings starting at $2,500
Used Nissan Armada
97 Great Deals out of 9,759 listings starting at $3,750

Used Cars For Sale

2014 GMC Yukon Denali AWD For Sale
12 Great Deals out of 177 listings starting at $22,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.