2.5 engine accellerates on its own
 

Hello everyone. I now own a used 2011 Mazda CX7. 55,000 miles. VERY nice condition. What could cause it to accelerate on its own when I have my foot on the brake, or say when I am backing into my garage? Scary as heck! The local Mazda dealer can't find any codes or problems with it.

Jammed floor mat? Loose floor mat?

Hot engine? Cold engine?

A/C on or off?

What RPM does it rev up to?

The engine is at normal operating temp. No floor mats in the way. Seems to happen when the AC is on.

Also the rpms go from maybe 700 rpms at idle in drive to about 1100 rpms.without hitting the gas and I have to hit the brakes hard and fast so I don't run into anything. It only happens once in awhile. Mainly with AC on.

I have a 2012 and it does the same thing. Although I have not tried it without the AC on. This kind of does make sense though since I always have the AC on.

Dealership took it and replaced the transmission under warranty but the issue has resurfaced.

Glad you got it replaced under warranty. But if a dealership told be they were going to replace the transmission to correct an idle speed problem, I'd look for another dealer.

replace throttle body....had the same issue