Hello all, I'm in need of some tech help. I have a 98 E320 that drives perfect warm. When started cold and driven cold, the engine seems to stop revving at about 3500 rpm. Then it almost acts like a rev limiter at 3500 or so, even floored. Then when it does go past 3500, it does not want to upshift in a timely manner, it'll hold 5000 rpm before shifting to the next gear.There is no check engine lightcoming on. Once the car is warmed up and driven to operating temp, it starts to work properly, smooth and nice. Any help would be considered a big favor. Thanks, Craig

 

have you just got this car?
does it behave differently before?
take note that if the gear shift lever is on P or N, the speed limiter is active to protect the engine from over revving.
also that on cold engine, it will retard the shift to heat up the catalyst till you reach the proper operating temp.

 

Thanks sleepwalker, I did just get the car. I did consider the idea that it may behave this way until operating temp is reached. The car does not act strange in park. I called a guy that I used to work with that now works at a MB dealer. He never heard of such a thing happening and suggested that it may actually be a fuel delivery problem. That sounds plausible but how come it only happens cold? I'm still trying to get a handle on this. Thanks!!!!!

 

I owned this identical car and found that it always behaved better when warmed up.
Sleepwalker (as usual) has hit the nail on the head. The catalytic converter has to be heated up quickly so the car will hold shifts when first driven cold. That in turn forces the engine to rev higher thus generating the heat needed for the converter.
It is entirely possible to hold a shift at 5000 rpm when the engine is first started. There is a simple solution--take it slower when the car is cold--its better for the car.
Even a warm engine in Park or Neutral will falter when it is revved up. The speed limiter comes on very early in these circumstances.
Enjoy your ride.

 

Craig:[/align]Two things come to mind given the age of the car:[/align]1. Could well need a fuel filter as well as a tune up.[/align]2. The transmission could be full of varnish.[/align]The marketing yuppie bastards at the German luxury manufacturers were trying to dispel the rumor that German cars are maintenence intensive (which they are) and were telling folks that they could go 13-15K between oil changes and that they never needed to service the transmissions. This led to folks buying numberous engines and transmissions at the 80-100K mark when good lubrication would have eliminated the problems. Unless you have the service records, assume that the fuel filter and transmission fluid/filter were never changed. While you're at it, change the plugs and the air filter(s). When dealing with the transmission which may well be gummed up, start by putting a can of Trans-X in and letting it spend at least 500 miles in there to cleanup and break down sludge before you have the fluid and torque converter flushed and changed as well as the filter replaced.It may interest you to know that the Mercedes Star Technical Expert wrote in a recent issue of STAR that the idea of a "lifetime fill" in the transmission is bull**** and that they need to be serviced every 30-40K.[/align]Regards,[/align][/align]Will[/align]