To eliminate the Trans as a possible cause, remove the dip
Stick check the level then smell the oil. A failing cat does not
Always smell like rotten eggs.

Your symptoms add up to oil on the exhaust, which is far enough back that it only burns when going that fast heats the exhaust far enough.

It is real possible that as someone else stated you have a dragging brake, as they smell like clutches. It is very unlikely that the smell comes from transmission clutches. The trans is a contained unit and one would have to get real close to it to smell it.

Maintaince free for the life of the lease!:rolleyes: No they most certainly are not. If it is the original fluid which it sounds like you should have it changed asap. Have you got under the car and pulled the sound panals off and looked for anything leaking? It probably wouldn't hurt to pull the wheels and inspect the brakes just to make sure...

Steve assume I have dragging brakes, why does this happen only when I punch on the accelerator? I test the car at 100-120mph without punching the accelerator and no odors. I know I really should not be driving at this speed. I hope I haven't upset anyone for this. I made sure no other car where around.

Hey guys, I just wanted to thank everyone for all their advice so far, This forum has been great and all experience with this forum has been positive.

I just want to let people know that I am a responsible driver with no accidents. Some people might get upset that I'm driving at over 100mph. I made sure there was no car around.

Hydraulic suspension fluid or differential fluid leak? both systems would get torqued when you "punch it".

OK guys, I have a serious problem. This may seem stupid to you but, where the heck is the dip stick for tranny? I took the cap which is black with red tab, broke the red tap and whao, no dip stick. the cap reads. Mercedes technichen.. .... I assume it is not a DIY without MB tools?

Right.
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1FX0MB1RS1QS0ZV9ZP&year=1997&make=MB&model=S-500-003&category=J&part=AT+Dipstick

The little red tab or "AT Cover pin" is a 70 cent part, I usually buy 2.
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1QC0RFPB41QS119AOS&year=1997&make=MB&model=S-500-003&category=J&part=AT+Cover+Pin
Paul
_______
98 E300

Fantastic, It's really been helpful guys. I think this is not a job for me, I'll just pay the $$$ to have the fluids changed, before I do any thing else.

Burning smell?
 

You cannot smell anything burning up in the transmission. The clutches run in an oil spray environment and any burning will not generate any odors you can smell.

It is probably you are smelling old oil leakage from valve cover gaskets between the exhause pipe and their heat retaining covers burning off as you get things really hot.

Wow, I'm really surprise by the response from people who suggest it might be an oil leak or tranny leak. I don't notice any leaks on the floor or on the motor. I just notice seepage, around the two cam thing. Well if there is that many suggestion about leaks, I'll have a careful look into it.

So does this mean the tranny is OK? How long should I expect the tranny to last before a rebuild?

Tranny life?
 

The life of the MBZ tranny depends on how well it is serviced (fluid and filter changes) and how it is used. Lots of high throttle shifts will 'use up' some clutch life and gear train life of course. However FAR MORE transmission die from neglect--the fluid is not changed regularly enough and the protective additives get exhausted and the oil oxidizes, becoming acidic and forms gum and varnish, attacks clutch linings, thrust washers,etc.

Unless you really work it HARD (lots of trailer towing, high throttle shifts) or overheat it, IF you change the fluid regularly and keep the cooling system in good condition, the transmission WILL last well over 300,000 miles.

These transmission SELDOM fail from normal wear. 99.9% of the time its due to inadequate servicing. 'Recomended' service intervals (in your case --NEVER) is not adequate for long transmission life--that service protocol MAY get you past the end of warranty--just--which seems to be the current focus of the New Chrysler/Daimler company.

Thanks for the info, this is highly valuable infomation. I have two cars, a 94 E420 and a S500 which I would like the keep for a long time, so I guess I should have the tranny flush and filter replaced every year? I don't have a problem with doing that. I average about 15K miles each year. on the 97 S500 I drive only 4K mile if even that each you. Should I wait two years to service the S500? I really don't don't do high throttle shifts, on the S500. Thanks again,