Rough Idle/Vibration?

[bjtheman1]

2007 Roush 427R w/ 50,000 miles

Been trouble shooting tons of BS and still working on things. Currently there is a rough vibration/idle coming from the front somewhere. You can feel it when in the seat, floorboard, etc it's noticeable. Feels like bass when it hits.

While listening and trying to narrow down this vibration, I think it's either my A/C Compressor or Harmonic Balancer Pulley. When at normal operating temp and idle you can feel the vibration pretty easily, but when I turn on the a/c each time it cycles my rpms drop and the idle is worse?

Anyone ever heard of compressor probs with rough idle or bad vibration?

I even took it to a Ford Dealership last week and they thought everything was fine. No vacuum leaks, or codes being thrown either.

[Mach1]

I doubt it's the a/c compressor, pull your belt and fire it up, see if it goes away.

[JC316]

Probably not the a/c. +1 to removing the belt. Busted motor mount maybe?

[danielhv]

Balancer

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[bjtheman1]

Probably not the a/c. +1 to removing the belt. Busted motor mount maybe?

I checked and tightened the mounts, they seemed ok.

Is the harmonic balancer supposed to spin freely? Mine doesn't, I tried turning it by hand but it doesn't move...is that normal?

[JC316]

I checked and tightened the mounts, they seemed ok.

Is the harmonic balancer supposed to spin freely? Mine doesn't, I tried turning it by hand but it doesn't move...is that normal?

The motor mounts are sneaky on these cars, you need to get a block of wood and a jack, then jack the motor up, if it lifts up any at all, then the mounts are trashed.

With the spark plugs in, you aren't likely to turn the balancer by hand.

[bjtheman1]

Took belt off, shake/vibration still there. Also, checked the motor mounts and engine didn't move.

[Lone Star Performance]

Have you done a compression test/leak down test?

[bjtheman1]

Have you done a compression test/leak down test?

Yep, compression was good all around. No issues.