2009 Focus Rough Idle

[usapatriot]

Automatic, ~46,000miles. I particualrily feel it when stopped or idle and it's definitely noticeable because a few passengers have mentioned it as well. Otherwise the car seems fine. I took a short video of the tachnometer and RPM display that you guys can check out here:

Video: http://youtu.be/8WOpzqTdQec

[Sponsor]

[Baldurs390]

i have the same problem with mine.... how do you get the tach to display like that?

[whynotthinkwhynot]

Originally Posted by Baldurs390

i have the same problem with mine.... how do you get the tach to display like that?

Electronic odometer trick, check our How-To Archive up there in the dark blue line above this thread title. Once you get it in that mode- which you can do without starting the car- watch what the readout is more than counting presses on the reset button.

I wouldn't expect the idle to be rock steady when you can look at it with 3 digits real time like that. It's probably a combination of things at 46k. First off I'd check the motor mount. That hydraulic mount is problematic at any time regardless of miles. Secondly- tune-up. If you're off, you're not far off. Going from 680 to 720 isn't a cause for alarm, but it might be a sign of greater swinging to come. I doubt I'd replace the spark plugs although I give P&I plugs a lifetime of 80k. I'd clean the ones that are in there, and I'd pay close attention to the condition of the coil plug boots. I had problems with those that weren't alleviated until 80k or so when I finally had enough of fluctuating idle. I found minor corrosion where the coil connects to the spring in the boot. I'd also check the air cleaner, and the fuel filter if not already maintained.

Best wishes, and I hope you figure out the problem.

[usapatriot]

I will follow through with those guidelines, thank you. There is no CEL and it only happens below 2,000RPM's beyond that and the engine feels normal and smooth so it's really only felt while stopped/idling.

I will start with cleaning the MAF, plugs, air filter, and replacing the fuel filter. Thanks again for the tips!