08 Tahoe oil pressure problems

[Isaiah Morgan]

I have a 2008 Tahoe Lt 4x4, 132k mikes. This morning when I was driving it I noticed the oil pressure gauge wasn’t holding a contestant pressure. It would go from 40 to 20 then back up to 40 the needle in the gauge just kept moving constantly. When I would slow down real slow to turn in somewhere it would drop below 20 for a second then back up. It is full of oil and motor seems to be running smooth. Has anybody had this problem or could tell me what it might be?

 

[wjburken]

I have a 2008 Tahoe Lt 4x4, 132k mikes. This morning when I was driving it I noticed the oil pressure gauge wasn’t holding a contestant pressure. It would go from 40 to 20 then back up to 40 the needle in the gauge just kept moving constantly. When I would slow down real slow to turn in somewhere it would drop below 20 for a second then back up. It is full of oil and motor seems to be running smooth. Has anybody had this problem or could tell me what it might be?

A very common issue on these vehicles is the o-ring on the oil pick-up tube fails and doesn't allow the oil pump to create enough suction to draw the oil out of the pan.

A quick test is it put an extra 2 qts of oil in and park with the nose of your vehicle pointing down. This should get the level of the oil above the o-ring. If you see your oil pressure come back up, that is likely the issue.

You may also have a plugged screen below your oil pressure sensor, but that typically doesn't cause pressure fluctuations.

 

[swathdiver]

I have a 2008 Tahoe Lt 4x4, 132k mikes. This morning when I was driving it I noticed the oil pressure gauge wasn’t holding a contestant pressure. It would go from 40 to 20 then back up to 40 the needle in the gauge just kept moving constantly. When I would slow down real slow to turn in somewhere it would drop below 20 for a second then back up. It is full of oil and motor seems to be running smooth. Has anybody had this problem or could tell me what it might be?

Add two more quarts of oil and see if the pressure stays up. If so, you've found the culprit, the o-ring.

 

[Isaiah Morgan]

A very common issue on these vehicles is the o-ring on the oil pick-up tube fails and doesn't allow the oil pump to create enough suction to draw the oil out of the pan.

A quick test is it put an extra 2 qts of oil in and park with the nose of your vehicle pointing down. This should get the level of the oil above the o-ring. If you see your oil pressure come back up, that is likely the issue.

You may also have a plugged screen below your oil pressure sensor, but that typically doesn't cause pressure fluctuations.

Okay! I will try this. Where is the oil pick up tube located?

 

[swathdiver]

Okay! I will try this. Where is the oil pick up tube located?

In the oil pan. It's basically at the bottom of the oil pump.

 

[Isaiah Morgan]

Okay, I’m guessing you would probably can’t get to it without pulling the engine.

 

[Isaiah Morgan]

Also could a oil leak cause this to happen? To make it lose pressure ?

 

[swathdiver]

Okay, I’m guessing you would probably can’t get to it without pulling the engine.

Well, it depends on where the leak is. A bad cam bearing can cause a loss of oil pressure but not a rear main seal gasket. You can change the o-ring without removing the motor and many do it without removing the front cover and some the opposite, taking off the front cover but not the oil pan.

Did you add the extra oil and see yet?

 

[donjetman]

The engine does not need to some out to change the oil pump pickup tube o-ring. I did this job in Nov of 2018, and a lot more.
The o-ring is near the front where the pickup tube enters the block. Then the pickup tube goes to the rear of the engine and down into the oil pan sump.
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