Check your Driver'* side Trans Mount at the rear (or closest to firewall). This mount has been known to break internally without seeing it. This is THE main mount that absorbs most of the engine torque! Another way to check if a mount is 'shot" is to place the car in "drive" with your foot firmly on the brake. Now place it into "reverse", if your hear a "Knock" or "slap" then your main mount is shot.

I measured from the bolt that holds the supercharger cover on to the front radiator brace, car in neutral 16 inches, car in reverse at 2,500 RPM 15 1/4 inches, car in drive at 2,500 RPM 18 inches. Does 2 inches of movement sound like a lot, because it sure looks like a lot. When you accerate forward it is trying to rip the forward mount apart. Hector could you take a look and see if there is a way we can limit it'* travel? This is a 2000 SSEI. 3.33 pulley. Thanks for everyone'* help. GM puts soft motor mounts in their luxury cars so you can't feel the vibration but, movement is bad for performance.
How can we add information to the message body?

Ok, I'll check the motion on mine as soon as I can get someone to 'drive' for me. I'm turning more horses than you are now, I think, so we should get a pretty good idea. Stock, my car wouldn't have been a good comparison.

I've never had the luxury of being able to see my motor movement under load, so this will be a learning experience for both of us. Stay tuned. In the meantime, just take it easy on the go pedal.

Well next Tuesday im getting new motor mounts, just to make sure, and I'll have to see if he can put a new O2 sensor on, cause im getting pretty crappy gas mileage.

Yes there were & still are! I'm assuming you're talking about the "wishbone" mount right below the A/Trans Channel cover on the Passenger side? The Seal for the Drive axle leaks onto this mount & eats it away! On my 87 3.8-3 kept eating mounts due to torque!

Man that'* a huge mother of a mount in front of the engine on my SSEi.
And it'* all soft rubber.
Damn it'* a 4.5" diameter donut 3" tall. That MUST contribute to a lot of movement, translating to response lag.

Does anyone sell a urethane replacement :?:

The other mounts must be similar.

If you open the hood with the vehicle in park and rock it back and forth standing at the front of the engine, you can see how much the engine rocks back and forth.

There has to be compromise between vibration transmission and performance.

I have a cheap trick if you want it but it is not what I consider safe. Ok Ok its not unsafe but I also would not recommend taking your MAF screen off either so I guess that might tell you what I consider "not safe". Ill post it in a bit I have to dig up the link.

Ty

In response to the post, as I mentioned in Mech & Maint I recently had to get a cat in order to pass emissions. Guess why it wldnt pass state? That'* right, a bad motor mount. Meineke ordered it and put it on and I decided to tell them to do the strut mount also since it was so cheap. I had them save the old part and that strut was in perfect condition. Within the same week I had Pep Boys put in a new starter and they said my trans mounts were bad. I have a leaky trans pressure line and the mech said that prob made the mount go. I didn't beleive them just thought they were tryin to mke more $$ and plus I figured the inspection place would have mentioned it. After the inspection place put the motor mounts in I can still feel the engine shift when I take off. Guess I do need the trans mounts. Can I do the job myself? Starter was covered under warranty but mounts aren't.

Yes, this is the mount that is soft, and it is soft so that you don't feel anything. It is bad for performance and hard on every line connected to the engine, vacumn, gas, radiator hose, exhaust system. Since I can't find a stiffer rubber mount, I am going to build my own. Thanks for everyone'* feedback. This mount has got to go. It might take me some time to get it done, you know experimenting.

Tell us more Ty