2001 SL500 is powered by the M113 V8 and it has plug wires. If they're fifteen years old they're shot........

Yea but replacing them would be just throwing parts at it.

People want help and results, not speculation and attitude.

I stand corrected. I don't know why I was thinking it was the late 119...I should know better.

Well it doesnt explain the check engine light, but I installed new motor mounts and got back my ultra smooth and quiet V8 Merc!!! Yay!!!

I will try and convince the car that it should not be running as well as it does and see what happens.

The only issue that engine usually has is ignition wires , you can monitor with tester and see which ones or none that are bad

I agree that as a matter of maintenance it sure as hell is not going to HURT the program, but it is not a recommended service by MB, nor, as I have stated earlier, having searched the forum, was there any reliable info that the ignition wires were likely to correct the problem. In fact I saw a couple of posts where they had been changed without any improvement. And, again, I was trying to isolate the issue and not just buy a bunch of parts, spray and pray etc....

But yeah, at this point, I am sure all of my wildest dreams will come true as soon as I change them out. ; )