Motor Mounts
Engine mounts are what separate you from the nasty vibrations and harmonics created
by the
internal combustion engine.
Without these simple items, you would feel exactly how
rough the engine in your vehicle
really is, even when running properly. In this article we will explain what an engine
mount is, what it does and why they are necessary for a comfortable driving experience.
Engine mounts are basically rubber isolators that are mounted between the engine
in a vehicle and the frame. They hold the engine in place while absorbing the vibrations
caused by the engine, creating a quiet, smooth feeling inside the vehicle. They
are made of rubber to absorb vibration without transferring it, but some manufacturers
have tried using a liquid (oil) filled mount to dampen vibration with some success.
In some performance applications polyurethane or solid steel mounts are used, these
mounts transfer
vibration, but can withstand
the abuse and high-horsepower applications seen in racing where a comfortable, smooth
ride isn’t really an issue.In a rear wheel drive vehicle there are usually two engine mounts, one on either
side of the engine. Front wheel drive applications may incorporate more mounts to
help control the torque of the engine, usually one on both sides and one in the
front center. Front wheel drive mounts are engineered differently from rear wheel
drive due to the fact that the engine is sometimes hanging on them due to space
constraints in front wheel drive vehicles whereas a rear wheel drive engine is usually
sitting on top of the mounts. Front wheel drives sometimes incorporate a “dog bone”
or torque mount, its sole job is to control the torque twisting of the engine so
that the other mounts aren’t stressed as much. These torque mounts are a common
failure on vehicles that use them.When an engine mount breaks it can cause many different things to happen; usually
you will hear and feel a
heavy clunk when
accelerating, this is the engine moving around in the engine compartment. Other
times the engine vibration may become more pronounced due to the mount collapsing,
this will transfer the vibrations of the engine to the frame, thus the interior
of the vehicle. This situation can cause the failure of hoses or anything that is
mounted to the frame from the engine. It can also cause the throttle to stick on
older vehicles with mechanical linkages instead of cables. In front wheel drive
vehicles, a broken mount can cause the axle to fail or
pop out of the transmission, causing the vehicle
to stop moving.
When one mount breaks it adds more stress to the remaining mounts,
and should be taken care of as soon as possible. Many things: oil contamination,
hard shifting (
manual
transmission), excessive
high idle,
or the combination of age and engine compartment heat can cause engine mount failure.
To inspect your motor mounts, lift and support the vehicle. Use a flashlight to
see if the rubber has deteriorated or collapsed from the weight of the engine or
if they are obviously torn, if so you will need to replace them. If they are oil
soaked from an engine or
transmission oil
leak, the leak should be repaired as well or it will cause the new mount to fail
as well.If you suspect your vehicle is in need of new mounts, they can be found at most
parts stores. They should last for many years, unless subjected to abuse from other
than normal situations. Be warned, some applications require a wide variety of different
tools and equipment to be able to lift and support the engine while replacing the
mounts. All mounts are bolted to the engine and
transmission, while
others are bolted to the frame of the vehicle. When purchasing new engine mounts
for your vehicle, always use an OEM (Original Equipment Manufacturer) or equivalent,
less expensive mounts are made of lower quality material and may not perform as
well or last as long as the higher quality part will.
If further assistance is needed, our certified car repair technicians
are ready to
answer your car questions.
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