ASEmaster

Can the engine mounts be replaced without the use of a hoist (i.e. lifting the engine w/ a jack and a block of wood under the oil pan) or is this just asking for trouble?

Also, after 20 years, can the mounts go bad, like start to sag or something? Are they solid rubber or is there more to them.

Thanks!

-Kennet

Siraniko

iTrader: (13)

not in the oil pan but in the bell housing. while ur at it, put a modified rear oil pressure regulator and whim the front cover to have higher oil pressure.

GavinJuice

you got any pictures of what you talking about?

LongDuck

Engine mounts (front) are easily replaced without hoisting the engine out or otherwise requiring removal of any ancillary components. The front 2 mounts are attached to the Engine Cross Brace and to the front member at the sides. These two mounts are different on left and right for 13b SE motors - may or may not be the same for other motors.

Removal of mounts requires that you place a hydraulic jack under the front of the engine BRACE (not the oilpan - as it will dent easily), using a block of wood to separate the load. Apply enough jack pressure to take the weight off the mounts. Loosen the single 14mm nuts on the top of the mounts that attach to the brace, then remove the 2 14mm nuts that attach to the front member. Carefully jack the motor up far enough that both engine mounts can be pulled free from the brace and crossmember. Insert new mounts, lower jack slightly, reinstall 14mm nuts all around, and lower the jack completely.

The engine mounts are 2 sections of bent steel, one in a 'dished' shape for the top, and a steel washer at the bottom, together sandwiching a rubber insert that isolates vibration. These will sag over time, and can occasionally break through the rubber, causing excessive engine/transmission torquing under load. It's not uncommon to have everything 'look' okay from the outside until you get the brace apart and find a broken rubber mount.

The other engine mount is at the back of the transmission, forming a 3-point suspension for the engine and drivetrain. This is similar in construction, and easily changed during a clutch job, or other transmission work.

On a higher mileage engine, I would strongly recommend AGAINST adding a Mazda Factory Race Oil Pressure Regulator set for 90psi - this will likely cause your engine to smoke excessively and burn oil due to weakened oil control seals and side seals leaking high oil pressure into your combustion chambers. HTH,

ASEmaster

Wow, thanks for the detailed explaination. Sounds like it shouldn't be too much trouble.

Long Duck, do you have any pic's of the front of your car? I was just wondering what your air dam looks like.

LongDuck

You can click the picture to get out to a larger image with more angles, but I don't have any other images - too big for download for most folks.

Let us know if you run into any snags with the engine mount replacement - it's a 2-3 hour job, at most.

SAH-RX7

Duck, you mentioned :
These will sag over time, and can occasionally break through the rubber, causing excessive engine/transmission torquing under load.

Can you (or anyone) describe what this feels like? I have an odd sensation in the gear shift that primarily happens when accellerating or engine-breaking.

Thanks!

-Steve

LongDuck

Loose mounts, either front engine mounts, or the rear transmission mount, will likely lead to missed shifts when you're accelerating hard under power. The reason for this is that the engine and transmission are allowed to torque beyond the normal range when the engine is under load, you push the clutch, pull it out of gear and shift from 1st to... 4th. Nice surprise, huh?

That's how you know one of your engine or transmission mounts needs to be replaced. The other way to tell is to let the engine idle while sitting on a flat surface - if your transmission shifter is bumping around back and forth when in neutral, you may have a problem with your mounts (or a vacuum leak that you need to fix to make it idle more smoothly!).

Usually, engine mounts are replaced as preventative maintenance and I replace mine every 20 years whether it needs it or not... (just kidding). I replaced mine last year, though, and for the $40 and peace of mind, it's worth it in my book. HTH,

Snapshot

Motor mounts are nothing more than a giant rubber washer sandwiched between 2 metal plates. You can change them out in your driveway w/ a floor jack. Where you will feel a bad mount is over a bump in the road when your frame shifts uncomfortably. You feel it in the frame – like in the floor panel under your feet.
ALWAYS raise the hood before you jack up the engine or you will dint it when your air cleaner trys to punch through!

mazda123x5

Well this was a great post I am going to change my engine mounts in the coming weeks mine are very
soft. And yes you can tell they are bad even revving
the engine up it moves alot and shifting is under
aceleration is the best way to tell my shifter moves
all over the place. Thanks for the advise hope
I can get them done with out to much trouble