I just recently came back from a 700 mile trip in the car. Got home and now my car will not shift out of first gear unless it is first driven about 5 miles in first gear( don't ask how I discovered this). Does this sound like vacuum? How hard is it to adjust this on the 240d? The car was shifting a little funny on the trip. It was slipping into 3rd gear prety bad toward the end of the trip. The rest of the gears engauged strongly. i am a porsche guy and don't know much about benz auto transmissions so any help would be greatly appreciated. Thank you Peter Hinkle

Greetings,

Although I have a 300Td and not a 240D I would assume that you tranny is either operated strictly off vacuum or linkage. Can you verify which it is? Don't assume the worst in any case simply because that's generally not the case for proper repair. Cheap parts, like plastic vacuum valves on the valve cover tend to fail much sooner than the tranny will. I would also look to see where my tranny fluid level is at this point, checked with hot engine in park, and running of course. Let me know your tranny set-up and I will try to help. This thread will also get alot more traffic if you post it in the Tech help section because it's not primarily a diesel issue.

Charles

Thanks, Charles. I have checked the obvious things such as fluid and loose connections. I suspect that you are correct in you sysnopsis that it is not the transmission directly as the car will shift after a drive of a few miles at low speed. The trans is vacuum operated and not mechanical. It has a vacuum module on the valve cover and I belive one more on the transmission itself.

We aren't talking about a cold engine in a cold climate are we? If we are, the shift pattern will hold the current gear longer before shifting if the temp is around 35 or so degrees, at least untill the tranny fluid warms up some. Most other shift related problems besides this generally refer to the combination valve on the top of the valve cover either leaking or extremely dirty, or the modulator valve diaphragm leaking. Do you have a mighty vac, vacuum tool to start testing vac readings? If not, it's a wise investment of $20 from your local O Reilly automotive store to test everything from ignition switch valves to IP vacuum valves and just about anything in between. Let me know where you want to start to test for vac, and what their readings should be.


Charles

Climate has no effect. It was 76F here this afternoon (Texas) and still had the problem. I have noticed in the past that in colder weather, the car did hold a gear longer until the trans was at operaing temperture. Engine temp doesn't have much effect as i always let the car warm up before i drive it anyway. We are talking a bout a car with 220,000 miles that otherwise looks and drives like a brand new vehicle. It truly was the case of a little old lady car. When i bought it, it still had all of the purchase docs in the glove box. Anyway, I do have a Mightyvac as it comes in handy on porsche FI. I haven't changed the filter In the two years i have owned the car so i am going to do that this weekend just for kicks. When I first start out in the car, it is not a matter of "late shifts", it litterally will not upshift at all until the trans heats up enough. This IS exageratted in colder climates. After it shifts once, all gears but third are basically "normal" at that point. The module on the trans was replaced about a year before i bought the car by MB so it does have a history of this problem with vacuum. I have been told by a few "reputable" MB shops that the 240d "inherently" shifts badly after so many miles and that there is no way to get the thing right again short of a replacement. I find this hard to believe. Any feelings about that? If I can get this problem solved, i will drive this car till it won't run anymore as I love the handling for a larger car and the stability in it's chassis. peter

Greetings Peter,


Let's try as you said the filter and fuid change to start. If tranny valve are gummed up at all they will loosen within a week of the fluid change. If problems still exist, they have been several post here as well as http://www.mbz.org describing the troubleshooting of the vacuum valve on the tranny as well as it's adjustment. Is the fluid a brown color now or perhaps a real deep burnt looking red color? If so it's time to change the nasty stuff out and renew with fresh, and your tranny will perform better, not saying it will fix your vacuum shift problem if the valve turns out to be faulty. I don't think I'd necessarily look at mileage when it comes to trannies or engines for replacement purposes. If it's worn out, it will let you know, but not in most cases all of a sudden like you describe. I have too many vehicles that are on the verge of turning over to 200,000 and the trannies aren't the problems with any of them, but in one case the body is falling apart around a good tranny and engine combo. The Benz is almost the baby with 160,000 on the clock and going strong.


Keep me posted on the results of the fluid change.
You can do the tranny vac checks anytime if you feel they are the culprit.


Charles