Throttle revving/not releasing on CX-9

Hello,

I've got an '08 CX-9 with 130k miles, orig.owner, and very well maintained. A week ago, I noticed a 'revving' sound while I coasted along with my foot off the gas pedal.

I've watched the tachometer and it seems to dangle in the 2,000+ RPM range for awhile during coasting, eventually dropping to the normal 800 RPM I'm used to in about 10 seconds or so. It seems to be getting worse by the day.

Any suggestions? I can have the transmission fluid changed first, but it seems like there might be a throttle issue. Maybe it needs cleaning? Or replaced?

Any help would be appreciated before I take it into a shop. Thanks in advanced!

~ Jonah

It could be a lot of things from a floor mat or junk under the pedal, sticky cable from the pedal to the throttle body, dirt & sticky throttle body. Find and fix the problem before it gets worse and causes a problem. There might be a device that is to close the throttle gently (not slam shut) that is malfunctioning.

Thanks! I was peeking under the hood, thinking maybe I can clean the throttle body myself, but I'm not sure. There are a lot of things connected to before the throttle that I'd hate to mess up.

One theory is that I've had a K&R air filter in the car for many years, and I recently had my oil guys service it. I usually do it myself, since I have the equipment, but went ahead and had them do it. I'm wondering if they didn't let it dry, and/or over oiled the filter afterwards, then the throttle (or related part) got gummy. Just a thought.

The floor mat and pedal don't seem to be the culprit, as the all weather Mat has a cutout and I tried lifting the pedal with my foot a few times today while idling and it made zero difference. Could still be the cable, but I'm focusing on the throttle region, especially since it no longer seems to be related to the tranny. Those shifts are fine, and it's doing it even in neutral (hanging about 1800 RPM for a bit before eventually going back down to 700).

I'll update once I figure this one out.

My experience and that of many others is that the K&N and other so-called performance air filters offer no benefit and the possibility of problems, as you state. There is no way an oil filter can save gas on a modern computer controlled engine, nor allow more power except maybe at very top rpms and wide open throttle--if any. There is the chance that the oiled cotton gauze (K&N) or oiled foam will allow dirt to pass through. I'd toss it and get any good brand of standard pleated "paper" air filter.

So, upon further inspection and driving the car, I don't think it's throttle or MAF sensor related. I actually cleaned both of those properly today with no change.

It seems the revving sound is actually not the engine, as the sound is tied to just speed. I shifted in neutral, manual mode, etc., and the revving is only tied to speed. Once up to 50+ MPH, it becomes masked. I only really hear it at slower speeds, under 50.

It feels like it's in the front end, so I jacked up the front wheels to look for any play but they seem fine. I'm sort of leaning toward a wheel bearing or shock related part but I'm surprised I didn't find much there today.

I may have to bring it in to the shop to diagnose this one.

Also, I suppose it could be a bad new tire. I recently put new Pirellis on the car, but I doubt Discount Tire will want to mess with this unless the regular shop tells me it's the tires.

Ok, fixed the problem. It was a bad left front wheel bearing, the right one was a little bad, also. Had both front wheel bearings replaced for $650 total and the noise is gone.

Strange it originally sound like my engine revving that sent me the wrong direction. It was a little peculiar that Discount Tire just installed 4 new tires on the car a few weeks ago, but perhaps the winter Blizzaks I took off were masking the sound since those are pretty loud tires a slow to moderate speeds.