Last post on Apr 19, 2013 at 8:29 AM
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Mercedes-Benz 300-Class, Engine, Fuel System, Diesel, Coupe, Sedan
#689 of 2328 Problems with the Transmission Reverse
Aug 16, 2005 (3:10 pm)
Hi, Sorry for posting my message again, but it seems that nobody saw it, maybe some of you can give me some help.
I have a 1992 Mercedes 300D Turbo Diesel which recently started with problems on the transmission. It works fine on D position, but on Reverse it takes about 4 or 5 seconds or even more to start moving, and then the reverse shift enters very smoothly and slowlly. When the car starts moving on rear direction, it makes a strange noise like vibration or jerking, till it finally stops the noise and starts working fine. Other thing is that if I press the acelerator down to increase speed before the reverse shift is completely engaged, the car jumps a little before it starts runing right.
I remember I had some problems before with the transmission of the same car and the problem was a vaccum valve that was in stock, do any of you have had a problem like the one I have?
Thanks for your help.
#690 of 2328 Re: Problems with the Transmission Reverse [mercedes300d]
by Mr_Shiftright HOST
Aug 16, 2005 (3:50 pm)
I'd check the fluid and if it's at the right level I'd do a major service anyway on the transmission; other than that, you'll have to tear it down and investigate I think. Noises inside a transmission are not a good sign, nor is slippage of any kind.
#691 of 2328 Re: Problems with the Transmission Reverse [mercedes300d]
Aug 17, 2005 (8:16 am)
My recent transmission shifting problem was solved by cleaning the valves inside the transmission and adjusting shift points. Be sure to take it to someone who knows about MBs; ideally someone who does only MBs.
#692 of 2328 Re: Problems with the Transmission Reverse [brakeengr]
by Mr_Shiftright HOST
Aug 17, 2005 (12:13 pm)
Well anyone who works on German automatics should be okay. Grinding noise isn't a good sign though as a sticking valve body might not cause something that noticeable.
#693 of 2328 time for a rebuild?
Aug 18, 2005 (11:57 am)
what are some tests that I can do to check to see if my '78 300d is in need of a rebuild? Its only got 84k miles but....its burning more oil then I would expect. Constant blue smoke and burning 3.5 quarts in 2,000 miles. Half the 2,000 miles are highway miles but that seems like a lot of oil to me.
The engine seems to be running fine, its usual sluggish self. I have changed all the filters and fluids and ran a couple of rounds of injector cleaner.
Any suggestions would help. thanks
#694 of 2328 Re: time for a rebuild? [tijolo]
by Mr_Shiftright HOST
Aug 18, 2005 (3:46 pm)
cylinder leakdown test will reveal all.
#695 of 2328 Looking to buy a 300D turbo, curious about biodiesel/high mileage?
Aug 18, 2005 (10:44 pm)
This is in reference to http://www.craigslist.com/sfc/car/91771703.html
I have emailed the seller for more information, but have yet to hear back from him. Hopefully I can see the car, subject it to my extensive battery of tests (much of it gleaned from reading this thread), test-drive it, ask a ton of questions, and if everything looks good, take it to a trusted Mercedes mechanic I know to do a full inspection on it.
According to the pictures and the (albeit brief) description, the car looks to be in good condition. Seller wants $4,300, which is a bit high. Blue Book private transfer is about $1,200. I'd probably make an initial offer around that, and haggle.
The only potential problem I see from here is mileage: The car has 248k miles on the odometer. Status of service records is unknown, but will be asked about. I'll definitely ask to see them. I will, of course, consult with the mechanic to examine the vehicle before I'd purchase it. I'd like to get (hopefully this isn't unrealistic) at least 150k more miles out of it before having to do major work on it. I'm fairly mechanically adept, but unfamiliar with Mercedes internals...I do, however, know a few people who are rather familiar with them, and who would help me out with any hands-on work I need to do. I'd prefer to do as much work as possible myself to avoid high service costs.
One interesting bonus: the car has been modified to run on vegetable oil, and comes with the filtering/fueling station as part of the purchase price. Depending on the quality of the station, it might be worth an extra thousand dollars, maybe more or less. The fact that the engine is pre-converted to biodiesel is a plus too, as I was hoping to do that eventually.
Assuming I can get the car and station for $2k-$3k, and that it is cosmetically and mechanically sound, does this sound like a good deal? I realize I'm asking for an opinion on a vehicle that you have not yet inspected, and with a fairly small amount of information, and I'll take those givens into account.
Aug 19, 2005 (7:58 pm)
aloha sam! this is a delayed reply to you, but thank you very much for your thorough explanation of transmission variables. i have found a 84 300d that shifts "firmly" and no slippage. (and she's gold and beautiful on a more superficial note). thank you very much for your advice,
#697 of 2328 SQUEALING SOUND..... TURBOCHARGER???
Aug 19, 2005 (8:15 pm)
aloha! i just bought a nice 84 300D with no apparent issues except.....
after driving a couple or less minutes there occurs a whistling/squealing sound ONLY at one certain point on the pedal, the sound reappears also at this same point when decelerating. it does not matter what speed i am going, nor uphill/downhill. i haven't noticed it starting immediately upon driving, so i might venture that it doesn't happen at very low speeds.
i reiterate: the sound is connected to very specific spot when pressing/easing the gas pedal both accelerating/decelerating. beyond that one point there are no funny sounds whatsoever and performance is fantastic
all belts are in good shape. no leakage. no temperature issues.
(i can't check mpg because odomoeter is broken, but it seems to be pretty damn good). i can't inspect the engine while the sound is occuring because it only occurs while driving. (unless you have some suggestions for how to?).
my initial thought was turbocharger issues but i have limited understanding of this, so i don't understand why it would happen relevant to gas pedal and not specific speed nor gear? bearings seem unlikely since there is no sound at higher/lower speeds, increased/decreased acceleration. maybe it's not the TC and there's some linkage in the fuel system that would create such a sound? fuel pump? i just don't get it..... do any of you???
thank you!!!!!!! (by the way, i am very happy to join all you in the ranks of MB diesel fans, this is the best car i've ever driven! it took me awhile to find her but i'm so happy i didn't settle for a subaru! biodiesel coming soon!)
#698 of 2328 INSTRUMENT PANEL LIGHT
Aug 19, 2005 (8:18 pm)
any tips on replacing the instrument panel light and/or adjustment knob on a 84 300D, depending which one is faulty, without removing the steering wheel etc? i'm just figuring out this car, are there secret back entrances? has anyone ever just pulled out the knob and re-threaded it? i'm sketched out by little plastic breakable things.