S320 Transmission stays in second gear too long
 

When I start my 96 S 320 let it warm up for a couple of minutes and drive off, the car will shift fine to second gear, but will not shift into 3rd gear for some time. Either, the RPMs have to reved pretty high inorder for it to shift to 3rd, or the engine has to be warmed up a lot longer, maybe ~ 8minutes. after a good warm-up it shifts to 3rd ok.

Is this normal or does this sound like I may have transmission problems evolving?:confused:

It is normal. The reason for it is to help the catalytic convertor heat up faster, prolonging its life and reducing emisions.

Yep, completely normal.

Your car has an upshift delay valve which delays the shift from 1st to 2nd gear to warm up the cat quicker to reduce emissions.

Thanks for the information,

I'll make sure I warm the car up before moving. I noticed if I let the temperature guage move just slightly the car shifts ok.

upshift delay valve
 

Please tell me how I can remove this "brilliant invention" for good so that there won't be anymore of this delay in the gear shifts when we go out every morning. Its a curse and torture to have to wait for this thing to go its course every morning like an oldie waking up. If you try to quicken this up by stepping harder on the gas, the car struggles, make lots of noise and you get a real stiff kick in the backsides when it finally decides to change. If you let it take its course, the knock won't be so hard. However we have to negotiate this steeper slope every morning and HAVE to step hard on the accelerator to get up and over it, no choice.

I dont think that its possible to change this feature. Why would you want to? Its the best way to heat up the cat converters and keeping them in good order. I was thinking, an S320 shouldnt have troubles going up a hill when its cold! I have a 94 E280, when I turn it on in the morning stone cold, it idles high for about 30seconds then goes to normal idle. i drive off up a hill everyday too and its fine

Chris

300TE
E280

gfdent

Just get in the car, drive-off and it will warm up quicker driving it. You don't need to sit there idling it. If it is so cold you need to idle it before driving off then you need a block heater.

delayed shift
 

Christian, I am sure that you will agree that there must be some other better or best way to do the job of preheating the cat without this unfortunate delayed shift and hard knock as it does it. Tell me why nobody has followed this wierd way if it is really necessary(to preheat the cat for whatever reason) and why nobody is complaining about this crazy invention in any other car? Thats because they had better engineers who thought of better ways thats why. So simple. Their most important requirement was for a smoothly changing gearbox all the way. Nothing else was to get in the way.

What do u mean hocky...are u saying that mercedes did the right thing by doing what they did with this? like holding the gear when its cold to warm it up?

Other cars do it. My mom's 740i, my dad's Tahoe, what else? It is almost an industry standard. BTW, my car does it, too.

Shortly this preheat of the cats to get them operating will be passe. NASA has developed a cat that works almost immediately at startup. It should make it into automobile production in two to three years.

I've noticed that my wife's E320 holds in gear until she exceeds 30 mph or the temp gets up to x degrees.

If you want to disable this 'feature' just disconnect the plug from the solenoid valve with the green vacuum lines connected to it.

This will cause a fault code to register in the engine management ECU as it checks to see if the solenoid is connected, but it shouldn't have any other effects.

I for one don't think it's right. On mine, the delay between the 2-3 shift can be three or more seconds. If I ease up on the throttle, I can get it to shift smoother. It will do this as long as the engine temp is under 60 deg C. If the temp gets to 60 or more, the shift is perfect.

None of my other Mercedes have done this.

delayed shift
 

Can somebody tell me why the cheap cars don't have this nasty feature? Don't they all have cats now, especially with the petrol injected engines? My Toyota Camry and Toyota Corolla start off and change like a knife cutting through soft butter! No waiting period, none of the suspense when its going to happen, just off you go like nothings happenned.

I don't have that problem:D