Changed some stuff out, and some questions

[97C28O]

I put in new shifter bushings today. There are 2 Located under the car but I only needed to put 1 new bushing in.

Here is the shifter without the bushing ( I have already removed the clip)
http://farm5.static.flickr.com/4018/4485399655_b630a44051.jpg

Install was very easy. Tools needed was 1 flat head screwdriver and a long needle (flat) plier. Used the flat head to lift the clip and slide it off the pin. Then unhooked it and placed the new bushing in. I used the plier and squeezed it into the hole, the black flat piece. and then reinstalled everything. 15mins?

I also changed out the oxygen sensor since I had a CEL for it long time ago. It was straight forward for that all you need is a oxygen sensor wrench with an extended offset. The extended really helps because of the exhaust pipes and such small area to work.

While I was under the car I noticed a lot of grime, grease, oil and dirt right under the engine/transmission...

http://farm5.static.flickr.com/4058/4485399937_fb2eb1f457.jpg

http://farm5.static.flickr.com/4023/4486050872_dd08c4cd28.jpg
Anyone know what they could be from? Years of build up? Leak?
*I was notified awhile ago that I would need a new oil pan gasket, but I never had excessive oil dripping or even oil level changes..

The question:
Recently I noticed a lot of vibration in the car. I would feel it during a stop light in D and on the brake. Sometimes its pretty strong, I would feel it on the steering wheel, my seats and floor. Sometimes its light. Also when the AC is on, it seems to vibrate more, when I shut it down the vibrations lessen.

Some say the motor mounts, MAF, and many other things. Anyone have some more accurate answers and tips for my to check as an DIY?

[mazdalowandslow]

Moter mounts, I had the same issue.

[97C28O]

Hmm... I'll probably check it out again. Any tips on how on to tell the mounts are on its way out besides the vibration? Physical damages?

What about all that grease/grime in the pictures? Could it be from the oil pan gasket?

[Sulaco]

Tip 1 on motor mounts: it's a w202, known (though small) issue
Tip 2: they typically last about 70-100k miles.

2 on the motor.

Something not mentioned so far is the transmission mount. There's 1 similar mount on the transmission which serves the same purpose. It could very easily be the culprit. But if you're at more than 100k, I'd say you should replace all 3.

It won't HURT to leave them alone. I'm proof. I'm at 235k miles on my factory original mounts, and shocks, and o2 sensors, and so on and so forth.