Engine Revving out of control

[Blessed1102]

Good Morning. I'm new on here and new to owning a '05 yukon denali. I've had it about 7 months now. I was driving it back from vacation and it seemed like the cruise control was set at 2000 rpm but it wasn't. We were coming up on stopped traffic on I-95 and as I was braking, it was not slowing down and the rpm's were not dropping. I got to the shoulder and threw it in Park. The rpm's immediately shot to 5000-6000. I quickly shut it off. I let it sit and cool a little and tried to start it and it did the same. RPM's revved up and I shut it down. Check engine light did come on earlier in my drive but the truck was still running like a champ. I though possibly the plate in the throttle was stuck from sand and debris at the beach. It was fine and clean. Had to get it towed to a local dealer. Should know something some time Monday. Has anyone had any issue like this or similar? If it helps, I went to the dealer the following day and it started just fine. Seems like it must only happen when it is hot. I appreciate any suggestions or input.


2005 GMC Yukon Denali- All Stock

 

[Sasquatch]

When it`s running does hitting the gas pedal do anything? If not your throttle actuator control may not be communicating with the ecm and it`s stuck open.

I`m just not sure why something like that would happen only when it was hot.

The dealer should be able to pull the code from when the check engine light came on.

 

[kschumake83]

But we have to have drive by wire, so the punk kids can't do burnouts. We need to stop these companies from putting this useless, dangerous crap on our cars. What was wrong with the $10 throttle cables that came on the older models like mine.

Now that my rant is over it sounds like the electronic box on the side of your throttle body is going bad, or a loose or corroded connector. But if is caused by heat I would put money on the box

Sent from my SGH-I747 using Tapatalk 4 Beta

 

[Gzes]

Did you stomp on te pedal to see if t would ge loose of gunk making it stuck? Why would they remove the cable? That type of electrical crap is what screws people over. Ill stick to a throttle cable enabled car or truck..

 

[Blessed1102]

Once I noticed it on the interstate I did stomp on it so it would down shift and maybe break some trash loose but when u went back to cruising speed and right around 2000 rpm's, it continued to do the same thing. Reason I thought it might of been the throttle was b/c it did the same earlier in the week but it was was just below 1500 rpm. Hopefully the dealer diagnoses tomorrow morning. I'll let y'all know what I find out.

 

[Blessed1102]

Spoke with the dealer today. After a lot of driving and not being able to replicate my problem, they began to close it up. The mechanic noticed the plastic engine cover was unattached and just laying there. Haven't seen it yet but the intake manifold had a hole in it and someone had put RTV over the hole and the stud was missing. Have to replace the upper manifold. I'll try to get pics of the old manifold to post.

 

[Blessed1102]

Found the culprit. The intake manifold was broke where the bolt for the plastic cover mounted in the front. The plastic that the bolt screws into was snapped off in the past and then RTV'd in place. Got a pic attached. Hopefully it works