There are four motor mounts. The one on top by the passenger side fender holds that end of the motor up. There is one hidden under the battery tray, that holds the end of the transmission up, and bolts to the side frame in the engine compartment. To see it you have to take out the battery and unbolt the battery tray. Then there are two motor mounts on the sides of the transmission & near its bottom, that really keep the engine/transmission from twisting. The one in front you can see if you look below the upper radiator hose. The one in back is pretty well hidden, but is in the same relative position as the front one. They both are supported by a little subframe that runs from just below the radiator to behind the engine compartment. This subframe has to be unbolted and lowered when you want to change the transmission fluid and its filter. (And you need to put a jack under the bell-housing of the tranny to hold it up, or your wont be able to get the subframe pushed back up to bolt it back in).
The motor mount on the back side of the transmission (toward the firewall) commonly gets coated with any oil leaking from the engine or transmission, because of the air blasting back as you drive on the highway. This will soften the rubber of the motor mount, and it can begin tearing.
So if you see that a motor mount is visibly torn up or oil soaked - its bad or going bad. However it will never result in the motor dropping down much or twisting out of position, but it may cause some increased vibration or motor noise at times.
i dont know about the 4th one, never saw it, as a matter of fact, when i looked up mounts, on over 5 diffrent parts websites, i only found 3. so either you have some wierd set up or this 4th mount you speak of is dealer only
One way to tell if an engine mount is bad is to pop the hood open, start the car, step on the brake, put the engine in gear, and step on the throttle(while still holding the brake) a bit and watch the engine. If the engine moves around its probably a sure bet at least one of the engine mounts are bad. I know on my car it is doing that, so now I just have to get the set of mounts and replace them one of these days, as I'm tired of the vibrations when stopped at a light. - Peter
I have three 2nd gen. Escorts, all 1.9L engines. They all have the same 4 mounts. From the www.rockauto.com catalog, I find the one on the front of the tranny is in the 'engine' listings, & called the 'front motor mount', while the one behind the tranny is in the 'transmission' listings and called the 'transmission mount'.
The one in back is easiest to see if you are under the car, looking up from below the axle shaft where it comes out of the tranny. That mount will be about 5 inches further back, and They are very easy to change when the tranny is out of the car. Its about $9 + shipping.
The factory service manual for my 1995LX lists two transmission mounts and 2 motor mounts. For some reason the stores and online parts lookups refer to the front transmission mount as a motor mount (and it does connect to the transmission).