Ford Focus Forum, Ford Focus ST Forum - View Single Post - Idle vibration
Thread: Idle vibration
View Single Post
Old 10-06-2012, 03:02 PM   #21
suss6052
Focus Addict
 
suss6052's Avatar
 
Join Date: Feb 2012
Fan#: 95752
Location: ..., MI
What I Drive: 2013 Ford Focus ST2 Ingot Silver

Posts: 12,708
Points 9,741, Level 66
Points: 9,741, Level: 66 Points: 9,741, Level: 66 Points: 9,741, Level: 66
Level Up 23% Completed
Level up: 23% Level up: 23% Level up: 23%
Forum Activity 28%
Activity: 28% Activity: 28% Activity: 28%
FF Reputation: 24 suss6052 Great Standing Member
Buy-Sell-Trade Rating: (3)
Quote:
Originally Posted by paul21 View Post
If your car feels mostly smooth then random harder jerks at idle, you should reset the car computer by disconnecting the battery for ~30 minutes or something and letting the engine idle for 5 minutes when you start it back up.

If your idle is smooth but causes a lot of vibration in general, then it's the motor mounts.

12B37 increases idle RPM from 700 to 800.
My car was built after the date range for the 12b37 update, but still idles at approximately 680 rpm with the a/c off and in park with my foot off the brake, or 750 rpm foot on the brake in gear with or without the a/c on approximately. At no point is the idle over 800 rpm per the digital tachometer displayed in test mode. Once you take your foot off the brake the rpms increase as the car begins to engage the clutch for 1st gear.
suss6052 is online now  
    Reply With Quote