Focus buzz

07 Ford Focus has major buzz/rattle when driving. Seems quiet at idle. Do these econo cars suffer from old motor/trans mounts? I heard use factory mounts or else.

Where is the noise coming from? Does the noise change with acceleration or when you turn the steering wheel? If so, which direction? If any of this is true, it would be wheel bearings.

Let me rephrase that. It has a MAJOR engine compartment buzz. You would think the motor was going to fall out. Like a fool, I got a different fomoco pass side motor mount from a junkyard car. And buzz was TWICE as bad. I looked in rearview mirror and it was so blurry I couldn’t see cars behind me. Put old mount back on. The entire motor buzzes. Not a low down heat shield buzz.

Test drove a 2004 Focus in 2004, car was ok but I didn’t buy it, because the buzzy engine would have driven me mad. You have tried a junkyard one and put your bad one back on. This video shows how to take the weight off the mount to tell if the mount is bad and install a new one. Oops site won’t let me upload the video. It just said put someone in the car and run the engine in park, then shut off the car.Put a a jack and a piece of 2x4 or 2x6 under your oil pan near the front. Jack it enough to remove some of the load , remove the 5 bolts that hold the mount, then jack up until the mount separates from the fender. Have the person in the car and start the engine, if the person in the car can hear the difference, replace the mount. I would have the new mount on hand, no sense doing the work an additional time.

Yes

Pay particular attention the motor mount on the passenger side, beneath the coolant reservoir

Those commonly fail, tearing and leaking out the hydraulic fluid

Lots of $40 pass side mounts online. There are $65-75 hydro mounts and $100 fomoco mounts. Hmm , try a cheapo for 75 or so or bite the bullet and spend 100?

have you yet verified your motor mount has failed?

Have person in car listen to motor idle
Lift motor off pass mount
Run motor, compare sound?
Why do I need a helper?
Can’t I listen to motor after I lift it?

Take a look at the crank’s harmonic balancer too. Seems unlikely with that new of vehicle, but doesn’t take much time to check for something obvious. The harmonic balancer, crank pulley, and flywheel are all original to the vehicle, right? No work done involving any of those parts?

It’s already 10 years old . . . might already have a lot of miles