Hey guys, Im a noob to the site, had my 06 GT for a few months now. When starting cold the engine will rev up and down after about 10 seconds of starting. Happens each morning. Its a slight rev, nothing too heavy, lasts no more that 10 seconds but I am just concerned now. It hasnt went away yet. Any thoughts??

 

Welcome!

How high/low do the RPMs fluctuate? Normally you will see anywhere from 1500-2k RPMs on startup, and then it should drop to 1k, then then down to normal (around 700 maybe? Can't remember).

Do you have the stock tune on the car or do you have a CAI/tune?

How about accessories running on startup; particularly is the A/C or heater on when you start the car?

 

Rev the crap out of it!

 

Yea, its around 1500 RPM's. It fluctuates very little, maybe a RPM level or two but not more than 1700 or 1800. Everything is stock, no tunes or CAI. A/C, heater not on.

 

Will that really help? lol

 

Err...no...don't rev a cold engine....

I think what you're experiencing is normal.

 

Hey...I had the same problem with my 06' mustang....in the mornings id start my car up and it would rev up and down...up and down....so I found some info about it...what I did was....disconnect the battery...take off the Throttle body and clean the gunk and grease off with bake cleaner or whatever you got that can get the stuff off...then reconnect the battery and start her up....I was sorta skeptical about doing it at first but it worked....hope this helps...let me know

 

I would definitely clean the throttle body, but to be safe I would recommend an actual throttle body cleaner and not brake cleaner!

 

I guess it may be normal if others experienced it also.

I will try cleaning the TB over the weekend. I will let you know if that helps.

Thanks guys.

 

Yes, this is normal. The pcm/Ford has "rpm adders" for air intake and coolant temps during start up.

Casey