As a lot of you know, I have an '05 C230K, which I have talked about on this site for the past 163,000 miles of driving it and tried to answer questions I thought I could handle here on this site. After asking my MB service writer when I should change the transmission fluid and filter on my car, he told me, "Oh, NEVER.....it's lifetime". So, of course, I changed the fluid and found out that, no, it's not lifetime. The fluid was pretty black and the filter had some gunk in it. Now, I have just changed it again at 162,000 miles and same thing. The independent MB garage where I go now told me that he has seen a LOT of these trannys go out around 130,000 miles, and that most of them could have been saved had the owners just changed the fluid. So, there you go. Lifetime to a Mercedes dealership must mean the "life of the transmission", which is going to be really expensive to replace. So, this is just a warning. CHANGE THAT FLUID AND FILTER NOW, or be prepared to shell out the big bucks later. This is, of course, if you plan on keeping the car such as myself. And I do. Mercedes uses a special tranny fluid and you will need some other small items to change it, but it is worth it in the long run. There's a 13-pin connector that should be replaced, a couple of seals, a gasket, a filter, and the fluid.
ONLY use the fluid from MB and don't let a Jiffy Lube or other oil change place put something wacky in there. It won't work and you will ruin the transmission. Hope this helps out some way towards keeping your car happy and running smoothly.

 

Mrcoyote,
My c230 has 82000 miles on it and I've just change the trans oil and filter as you've suggested. What is the recommended intervals for oil change on this model?
Also, I've just changed the O2 sensor(pre catalytic) and the wire seems to touching the part of the engine(transmission).
The mechanic told me this shouldn't cause any problem.
Is he correct on this matter or should the wires of O2 sensor wires not touch any part of the engine.
Last question is when did you replace the batteries for your vehicle? and is there a particular brand you would recommend for batteries
Let me know. Thanks.

 

Some good questions here, and I'm going to preface my remarks with this statement: Others may disagree with me and I'm sure some of them will. These recommendations are my opinion only. OK.

My independent MB mechanic who has almost 35 years experience working on these cars alone, told me about changing the tranny fluid and recommended a fluid and filter change about every 50K miles if you want the tranny to last. If you mean OIL change intervals for the engine oil, people will give you all kinds of answers to this one. I change my own oil and filter about every 10K miles or maybe slightly less. I use Mobil 1 full synthetic only and the filters I get on the internet. The O2 sensor wire should be OK even if it touches the engine somewhere. I think your mechanic was right on this one. The independent MB mechanic also agrees with me on my engine oil change/filter change interval. Again, for some people this may seem too soon, but I am trying to make the car last past 200K miles, and so far, I am right on track. I am getting ready to replace the spark plugs again any day now. I did it at almost 90K+ and the car needed it. Now at 164K, I am going to do it again just for the heck of it. Hope this gives you an idea or two. Oh yeah, I almost forgot....the fuel filter was replaced twice.....once at about 60K and again at about 120K.
I cut both of them open with a hacksaw and looked in there...but cutting them open made such a big mess out of the element inside, I couldn't really tell much.

 

Thanks mrcoyote for you valuable info.
When did you replaced the batteries for your vehicle?
I'd to change the O2 sensor because there was engine oil in the O2 connector(plastic end of O2 sensor) which had ruined the O2 sensor. The mechanic had to change the O ring (I don't know which O ring).
Did you had a similar problem with your vehicle where the oil had entered the connecting area of O2 sensor?

 

Hi, mercedes do a free transmission oil check, as you cannot check it yourself. I took my 1998 mercedes to the dealers last week as there was a bit of transmission slip when the engine was cold, I was with the engineer when he dipped the rod into the transmission and the oil was low, but bright in colour, (bright red in colour) he topped up the oil and re-fitted the cap and took the car out on a road test, then put the car upon to a ramp and took a look around he found no leaks, and my mercedes has been perfect todate. he also gave a free bit of advice by mentioning the maf was faulty and told me where to get a paten part from (a credit to mercedes they were fantastic)

 

I have an '05 c230k with 79k miles and I have a few similar questions for you guys:

1) Is the transmission fluid/filter change something that I can tackle in the garage without making a huge mess? What all is involved besides dropping the pan?

2) Where exactly are the fuel filters at? Are they near the tank or under the hood? I assume they aren't too difficult to change?

Runs strong without any issues but I am going to change the spark plugs here pretty soon just to be slightly ahead of the game. Any other maintnance items I need to look at? Serpentine belt?

Thanks..........

 

This is an age old question that will get many different answers, I have been told by many transmission mechanics not to change the fluid, unless it is burnt. Some have said what happens is the fresh fluid breaks loose worn particles from the clutches and stops up the valves. I have had company vehicles that were maintained by the manufacture's maintnance shedule, and the transmission still fail at less than 80,000 miles. I have had vehicles I bought new that went over 200,000 miles (american made transmission at that) with no transmision issues, without a single fluid change. It varies greatly depending on how much abuse the transmission gets.

 

Your fuel filter (there is only one) is underneath the backside of the car. You can see it tucked up under the car if you jack up the rear end and look kind of on the driver's side near the rear end. Get rid of those wacky clamps and get yourself a filter and some hose clamps that tighten with a screwdriver. You can find the filters online for a good price. Jack the car up, get a drip pan to put under the thing, and go for it. There's a little black plastic clip looking thing that holds the filter. Just undo it and it comes right out. The worst part is dealing with those clamps the first time you do the job. A pair of diagonals will get them off.
Don't worry, gas doesn't come shooting out of there like you think it might. Yes, some comes out, but it's no big deal. If you're worried about it, have something ready to shove in the hose from the tank. Like a tapered punch....that's what I use. Works fine.

Now, on to the automatic transmission thing> I am changing my fluid and filter frequently as suggested by my friend, a service writer at the local MB dealership. I know about the theory that changing the filter and pulling the pan loosens stuff and causes failures. All I can say is, I'm doing what I think is right and what was told to me by a guy who sees these cars every day of his life and knows what goes on them and when. Yes, abuse, heat, etc. play a big role in tranny life. Heat is the killer of automatic transmissions. So, do what you think is right and roll the dice. Are you feelin' lucky?

 

Thanks for the reply Mr. Coyote. Did you do the tranny fluid and filter change yourself? How difficult was it? Is it possible to do in the garage with just regular tools without making a huge mess???

 

I changed the transmission fluid and filter on my 02 C240 about 6 months ago and it is very straight forward. It can be done in your garage at home. You will need the "torx socket" (E10 or E12) to fit the trans. pan bolts, and a transmission dipstick measure tool to measure the correct level for the fluid. If you're only draining the fluid from the pan, you can measure what was drained and replace the same amount with new fluid and filter (approx 3.75 to 4 liters). This only works if the transmission had the correct level before draining.