I replaced my motor mounts on my SL, I got Lemforder ones, I have had them for a year, no problems. I had surging problems with my SL too, it was kind of jumpy at idle, when sitting while in gear. I replaced the purge valve and the post cat O2 sensor, I don't know which one fixed it, but it doesn't do it anymore. Also my trans which is the prior version to yours will start soundinng kind of rickety while in gear and the foot on the brake, only when you open the door or have the window down you can hear it, Usually when I change the trans fluid it quits. ANother thing to check on the 500 engine is the breather tubes, all those under the air cleaner assembly, they get brittle and break, check them out because that can cause surging as the computer compensates for vacuum loss. Good luck!
Brian

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Brian W. Heitman

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