motor mount diagnosis?


Old 02-04-05, 08:38 AM
Thread Starter
Join Date: Sep 2004
Posts: 238
motor mount diagnosis?

I have a 97 3.1 l Chevy Lumina.

It has developed a shudder when braking. The shudder is most apparent when slowing from ten mph to zero as when driving in a parking lot and is felt through my feet and not really heard. The weird thing is that the same shudder is repeated about 75% of the time when brake is released and I start moving again. I looked and poked at the suspension parts and everything looked and felt ok. I do not suspect the brakes because it happens when the brakes are released too.

I did notice that the crankshaft pulley side motor mount was oily. Are the mounts oil filled? The tranny seems to be leaking at the drive shaft on that side so maybe it is dirty tanny fluid or maybe motor oil. Can these 3 fluids be distinguished when mixed with road grim? Could this be the cause of the shudder? How do I tell if the mount is shot? This is a $70 part at AutoZone, so I do not want to swap it out just for fun.

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Old 02-04-05, 03:38 PM
Join Date: Apr 2003
Posts: 174
I am not saying that the upper mount is causing the shudder, I will just chime in on replacing the upper mount. I had 2 bad mounts on my 93 Grand Am 3300, it was so bad that when I used reverse it would howl and shake so bad I thought it was a bad tranny, after I replace them (along with the tranny mount) it raised my engine almost 2 inches. Yes the upper is oil filled, you can get all 3 mounts for 79.00 at auto zone or ebay for about 40.00. This is how I did mine, it may be a little different for you but not much, I also thing the mounts are the same, just installed upside down from mine. To change the upper and lower mounts is real easy, put a jack under the pasenger sider of the oil pan (dont worry, it will not hurt it as you do not raise it much, make sure you have a 2x4 as a buffer. Jack the engine just enough to take the weight of the mount. Take the bolts off from the mount to the engine, then the mount from the wheel well, drill out the big rivets and install the new mount on the mount bracket,then install the bracket to wheel well and mount to the engine, you may have to lift the engine up as the new mount has not collapsed. Now, do not lower the engine and under the motor is the lower mount, remove the 2 bolts and replace mount, use the same bolts, real easy. Lower the engine after you replace these, report back to see if it helped, if not, I will explain the tranny mount.
Old 02-04-05, 03:49 PM
Join Date: Apr 2002
Location: Pittsburgh,Pa
Posts: 2,417
Next time it happens put the car in neutral and see if it still happens.It sounds like you are describing a partial torque convertor apply when it shouldn't be applied.

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