Help with RPM Fluxuation

[Shane71]

I have a 2004 Z71 Chevy Tahoe with 115K miles. I recently had the transmission rebuilt. There really has never been major issues but I recently moved to the Washington, DC area. Now when it is cold (especially in the morning) I am hearing a whooshing sound and my RPM's go up then immediately fall back. I am not sure what it could be. I had someone tell me it could be a sticking valve. Any help would be appreciated.

 

[M3PO]

Sounds like the belt driven fan to me. Do you have a check engine light?

 

[Shane71]

No check engine light. Again it only happens when its cold.

 

[Rivieraracing]

Clean out your throttle body!

 

[M3PO]

No check engine light. Again it only happens when its cold.

Sorry, I could have been more clear on my answer. What I was saying was: I think this might be normal, I had 02 Z71 with the belt driven fan before my 06 with an electric fan. The belt driven fan kicks on when first started/cold, I am not sure why, but they do. So it might be normal, have someone else start it cold, while you look at/listen to the fan, JUST KEEP YOUR HANDS AWAY!

 

[jplinville]

I think it's normal...Where did you move from?

 

[91RS]

Clean the throttle body. The transmission place disconnected the battery to remove the transmission so now the PCM doesn't remember the dirty throttle's leanred position.

 

[jaykel]

x2 on cleaning out the throttle body...will def help

 

[nick1126]

what about the idle air control valve

Someone suggested the idle air control valve which I have not tried.

Any help would be appreciated

Thanks
Ron
[email protected]

 

[91RS]

You don't have an idle air control.

Clean the throttle body. The transmission place disconnected the battery to remove the transmission so now the PCM doesn't remember the dirty throttle's leanred position.