Engine Revving in Park

[ugadawgs311]

Last week I received an “Oil Pressure Low” warning on my 2007 Z71 Tahoe (about 177k miles) while driving. The engine seemed to run ok with no issues. I checked the dip stick, and oil was low, so last night I added two quarts just the same as I usually do. When I turned the car on this morning, it was definitely jumpy and the RPMs seemed higher than normal, but the car was still drivable. After about 1.5 miles (maybe 5 minutes) of driving, I received an “Engine Power Reduced” warning. I was unable to accelerate, and eventually rolled into an adjacent parking lot.

I turned the car off and on, and the engine now revs up while still in park (as if I’m pushing the accelerator). I tried driving for about 50 yards, but the same warnings came back on along with traction control issues and stabilitrak issues.

What could be causing this? Maybe the throttle body? Is it related to the recently added oil, or just a coincidence? Any help is greatly appreciated!

 

[Geotrash]

Last week I received an “Oil Pressure Low” warning on my 2007 Z71 Tahoe (about 177k miles) while driving. The engine seemed to run ok with no issues. I checked the dip stick, and oil was low, so last night I added two quarts just the same as I usually do. When I turned the car on this morning, it was definitely jumpy and the RPMs seemed higher than normal, but the car was still drivable. After about 1.5 miles (maybe 5 minutes) of driving, I received an “Engine Power Reduced” warning. I was unable to accelerate, and eventually rolled into an adjacent parking lot.

I turned the car off and on, and the engine now revs up while still in park (as if I’m pushing the accelerator). I tried driving for about 50 yards, but the same warnings came back on along with traction control issues and stabilitrak issues.

What could be causing this? Maybe the throttle body? Is it related to the recently added oil, or just a coincidence? Any help is greatly appreciated!

Almost certainly a coincidence with the oil. The only way to troubleshoot this though is with a scanner that can read GM-specific codes, such as a Tech 2, which you can get from chinacardiags.com for about $250. If you're on an even tighter budget, this one is pretty good:

https://a.co/d/0SZ5xJs

 

[ugadawgs311]

Thanks. So sounds like the oil isn’t the issue. I’m hoping just a sensor or something small like that.

Edit: any chance it could be computer related?

 

[Doubeleive]

sounds like multiple problems
low oil pressure could be oil pickup tube (or worse)
engine revving is something different, possibly the throttle body is goofy or even stuck open
how often do you do maintenance? when was the last time you cleaned the throttle body, intake, changed the air filter?

 

[ugadawgs311]

I just had it in the shop about a month ago to fix the throttle position sensor. That was giving me a check engine light, but there were no noticeable signs when driving. The overnight engine reving, stabilitrak, TCS errors came out of nowhere.

The guys at the shop didn’t mention anything else needed work while I was there (not 100% confident they checked though).

 

[Doubeleive]

I just had it in the shop about a month ago to fix the throttle position sensor. That was giving me a check engine light, but there were no noticeable signs when driving. The overnight engine reving, stabilitrak, TCS errors came out of nowhere.

The guys at the shop didn’t mention anything else needed work while I was there (not 100% confident they checked though).

probably need to take it back to the shop then

 

[Rocket Man]

This^^^. And I wouldn’t drive it until you find out what’s wrong especially if it’s revving up in park like you’re stepping on the accelerator, just putting it in drive while the engine is revving can damage the trans. No use making more trouble.

 

[ugadawgs311]

Thanks everyone. After checking the dipstick, it looks like the oil is way over filled (well above the five dots on the dip stick). Hopefully just draining and changing the oil will be the fix.

 

[AEChevy]

Hey, what about the Mass Airflow sensor stuck open. Or Intake manifold air pressure switch to high...

 

[Doubeleive]

Hey, what about the Mass Airflow sensor stuck open. Or Intake manifold air pressure switch to high...

nah, it wouldn't make it rev up, it would make it shift weird and gallop like a horse maybe or maybe not even start or start and then idle down and die