[LarryGee]

I took the 1981 240D in because there was a flare in the shift from 1st to 2nd. Beyond that, the car shifted fine. While it was in, I had him order and replace the 3/2 valve that had worn significantly at the lever and was not depressing the little silver plunger very much.

He turned the key on vacuum modulator in measured clicks, first one way, then the other way to see if that would make a difference and he said it didn't. So, he ordered a new vacuum modulator.

Now, the car is creating "excessive vacuum" as measured by his tool AND wouldn't shift out of first. So, he put the old modulator back on and the car still wont shift out of first. Still getting excessive vacuum.

Now he is telling me that sometimes a bad kick down switch might "block" the transmission from upshifting correctly so he is going to disconnect it and see what happens.

At this point, I'm getting a little nervous and looking for trouble shooting tips. Is it likely the new 3/2 valve, might be the culprit? How likely is it that it's the kick down. What could be causing such excessive vacuum pressure? Why would the transmission be stuck in first?

I don't recall in what measurement grade vacuum is measured but I think he said something about "100" and should be "60". I thought it was measured in "bars", with the correct reading being 3.8 bars on my car.

I welcome comments from anyone who may have experienced this issue or knows of the symptoms and solutions.

Thanks,

Larry

 

[Forcedinduction]

High vacuum causes early shifting, no vacuum causes delayed sifting.

Firstly, if the 3/2 valve was bad, why was he messing with the modulator?
Secondly, why would this be taking so long? Testing if the kickdown switch is at fault is literally a 5 minute process. Unplug the switch at the pedal, test drive, and results should be obvious immediately.

You are rightfully nervous, that guy has no clue what he is doing.

 

[LarryGee]

I replaced the 3/2 valve because the lever which depresses the silver plunger had broken. It was an easy fix.

Disconnecting the kickdown switch had no impact at all on shifting. It is stuck in first gear.

It's not a vacuum issue. It's a pressure issue. The pressure measurements in the transmission are way too high. He does not know what would be causing that.

Any other ideas?

 

[LarryGee]

I replaced the 3/2 valve because the lever which depresses the silver plunger had broken. It was an easy fix.

Disconnecting the kickdown switch had no impact at all on shifting. It is stuck in first gear.

It's not a vacuum issue. It's a pressure issue. The pressure measurements in the transmission are way too high. He does not know what would be causing that.

Any other ideas?

 

[Forcedinduction]

The modulator was installed wrong. Either it was installed incorrectly and the pin is not seated properly or the wrong pin was used with an updated part.

Have him reinstall the old modulator parts.

 

[SpartanPete]

I had a problem just like this on my old 240D when I blocked off a leaking vacuum line and inadvertently blocked vacuum for the transmission. Maybe when he worked in the engine he disconnected a vacuum line?