All 4 were replaced a while back. But the vibrations are quite bad in cold weather. Not sure what brand they are. Thought maybe it needed a hydraulic one. So I got a front one on Rockauto since it is easy to replace. This caused the vibrations to become terrible at idle speed. 5 days later I took it back out. Turns out metal to metal contact had occurred. It was pushed all the way back and touching its own metal housing.
Some possibilites:
The motor mount is defective and is pointed too far forward, or the rear one is also made that way and they needed to be replaced together. The bolt marks on the new motor mount show that it was mounted off center toward the rear, so that couldn’t be it. There is a little room for adjustment before the 3 bottom bolts are tightened.
The old rear one is defective and set too far back, and it has pulled the new front one too far back. Maybe the old ones were made to work together. The old front one was pulled back as well though.
The rubber is too soft. With the strength of two hands, I am able to push the top piece all the way to one side until metal to metal contact occurrs. Maybe the rear one is meant to be the stiff one that hold the engine in place, and the front one is meant to be soft? The old one was pulled back too though, but it is more firm and I can’t move it so much with my hands. It did not have metal to metal contact.
It is defective and missing whatever rubber part it should have to prevent it from bottoming out sideways. I couldn’t get close to pushing the old one hard enough to bottom it out sideways.
Rockauto won’t take it back if I installed it. If I say it is defective, I’ll probably get the exact same thing again.
Here are some pictures. The silver stuff on top is aluminum from the metal to metal contact. You can see that with one hand I can move it close to touching the metal edge on the other side of where the aluminum powder mark is. With both hands I can do it!
I’m guessing there are some other engine & trans mounts that are not aligned correctly or properly fastening the engine/trans to the frame, allowing this mount to also be misaligned. What is the engine/trans mount configuration on your car? For example, my Corolla has 5 mounts
Right (near the right fender, for the engine)
Front (near the bumper, an extension of the engine/trans mating line)
Rear (two separate mounts, spaced roughly along the trans/engine mating line.)
Left (near the left fender, for the transmission.)
Engine front, engine rear which is also connected to a piece holds the CV axle, engine top torque strut (“dogbone”) to body, transmission mount on the bottom on the left. The lower ones connect to the subframe which is also rubber mounted.
The engine front and trans rear mounts are torque axis mounts. They handle the weight of the engine and trans. They isolate bounce vibration and fore-aft motions. The dogbone is a torque windup mount so the engine doesn’t smack the radiator. So the ones at the side handle the engine fore aft shake normal for 4 cylinders so they are usually very soft. They need to be lined up in their centers before tightening them up so they don’t bind. Given that, investigate where the other mounts are in their supports and what they look like.
It might provide a clue to loosen some of the mounts, leaving at least two to create a rotation axis, then watch what happens to the mounts as you slightly manually rotate the engine/trans using some sort of jack or lever.
BTW, mounts are usually defined by their position w/respect to the chassis, not the engine/trans; i.e. if you ask for a “front engine mount” at the parts store, the staff may not be able to find one in their database.
I’ve seen instances where the engine will shake for some time with new mounts . . . even some factory parts . . . until everything has “settled in”
