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First I would like to say hello to everyone (first post here) and an early Thank You in anticipation to any informtion or guidance you guys can give (from what I have read so far on these forums, there is a LOT of good information to be had).

I would like to say up front that taking it to a mechanic is OUT of the question. I do not make enough to trow money at problems, and my fiance has more student loan debt than I care to think about; we are also saving up for a wedding in the near future. While I am not uncomfortable around cars. I have not worked on a Mercedes before and I would like to approach it with as much information as possible (especially since it's not mine). That is why I am here. I am more than confident that I can do any general repair on the car, and I could probably even rebuild the motor myself given enough time. Any question I ask, even if silly, is asked simply for the sake of reassurance. I am not saying I don't need help, but I won't ask questions like "what's that knoby thingy that I can screw off on the top of my engine for?"

Ok a little back story: My fiance was given a used C 280 a short while ago, and while the car is in good shape, I want to do some general repairs and maintanence to it. It's a 1994 (I know the forum says 1995 - present, but this seems like the best place to ask) and has just barely over 77k miles. She has had it for about half a year, but has been in school out of the country for about 5 months so it has been driven very little since she got it (she doesn't like to drive, so I drive 95% of the time). She was told it had been completely refurbished engine wise when it was purchased by a Mercedes mechanic (I personally don't buy that). It has VERY sluggish pick up, maybe a 2 second delay before any acceleration takes place from a stopped position, however once in motion it seems to respond normally. It also makes a low popping noise when in lower gears/speeds. It doesn't follow any pattern I can tell, and it only seems to last until late second gear/early third gear or ~30 mph (it's an automatic so it's hard to distinguish exactly where it lets off). It has also been running somewhat rough lately. It would seem, in my non-expert opinion that one of the valves is not firing all the time. We took it in on the weekend to get a smog check done and it failed. According to the test, at 15 mph the O2 and CO emissions were pretty high (about 10 times the state average), however at 25 mph the O2 emissions dropped to slightly above the state average (about 1/5th the state maximum, so easily passing) however the CO emissions were still high.

So now that you know what types of problems I am facing, what should I do to take it on? I already went out and got a new set of spark plugs and a new oil filter (I read somewhere that I need a copper ring also, and I believe the filter came with it). I was thinking if it's not too dificult, I might as well hit the gas filter while I am at it. I am pretty sure I changed the air filter when she first got it, but I can't remember if that was her car or her mom's, so I might just do that for the hell of it. Radiator might get a poor man's flushing and refilling, along with brake fluid checked. Is there anything else I should check for/inspect? Quick list:

- Change Oil and Oil Filter
- Change out Spark Plugs
- New Air and Gas Filters (possibly)
- Radiator flushing (if I feel it is needed) and refilling
- Brake Fluid and possible bleeding (again, if needed)
- Inpection of 'expendibles' like windshild whipper fluid, air in tires, etc.

Now a couple quick questions on how to do this (again, just to make sure):

1. What's the copper ring with the oil filter for? This one I am not sure on (All the vehicles I have changed oil on have used the American style of oil filters). Also, where can I find the oil filter? I heard it was in the rear of the engine on the driver's side. Just want to make sure.

2. Is there any trick to the spark plugs? It's also been a while since I looked under the hood of her car, but I don't recall seeing the cables to the spark plugs. I am sure they are there, but I just can't picture them when I think of the engine in her car. I assume there are three on each side, just below the top fo the motor; just want to make sure.

3. Where is the master brake cylinder? I assume it's on the driver's side towards the rear, but again, just want to make sure. Is there any trick to filling it? I assume it's just a screw off top.

4. Gas Filter. This one I probably won't even mess with, but I am under there so part of my tells me I should a least check it while I am there. Any tricks to it? Location? should I even bother? etc.

5. Any other advice you can give? Any common problems/fixes? Trouble areas? etc.

Once again, thanks for any help you can offer. I know this thread seems like an essay and a half, I apologize, but I like to be thorough.

Looking forward to your response.

Jacob
 

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2001 E320; 2002 ML500
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Wow! Where do I start....She probably got the wrong car. If cost of ownership is a factor, a MB can be (depending on how well it was maintained) very expensive to keep up with BUT if you do most of the work yourself and purchase the parts on-line, you can save a lot of money.
The '94 (M104 engine) had several major problems:
1)Engine wiring harness cracks and causes all kind of problems. If your car's original harness has not been replaced, it will need it sooner or later. The part alone is about $700-800.
2)The headgasket is prone to leak and this seems to depend more on age than mileage. This can be spotted easily (get under the car and observe if you detect any oil leak, especially towards the back of the engine). While most of the time this leaks oil to the outside without any bad consequences and can be driven for many miles, if you decide to repair it it can cost about 1K (at the dealer).
3)I've had water pump issues with this engine on both a '94 C280 and a '95 E320.
These are just some of the things to watch out for.
About your questions:
1)The copper washer goes on the drain plug screw under the oil pan. When you remove this screw to drain the old oil, you need to replace that copper washer. You will need a 13mm wrench to remove the plug.
The oil filter is on the back of the engine agains the firewall on the driver's side. It has a round black plastic cap. In these cars, you can replace the oil filter without replacing the oil, if you wish, as it sits on top of the engine.
You will need a special tool to remove this oil cap and it must be retightened to 25N-m.
2)The M104 engine is an inline six so all spark plugs are nicely aligned on top of the engine. You need to remove the top cover (several Allen type screws). Below this cover are the ignition coils (3). You must remove them along with the other 3 cable boots. Undernieth them are the spark plugs. It is easier than it sounds but make sure you pull the wires by the boot and not by the wires, otherwise you may break them.
3)The brake master cylinder is where you say it is. Very easy to spot.
4)The fuel filter is on the rear of the car on the passenger side next to the rear right wheel. There is a black plastic cover that you must first remove. I would replace it every 50K miles or so.
If you decide to drain/flush the radiator, make SURE you use either MB antifreeze or Zerex G-05 (at Pep Boys for about $11.50). DO NOT USE ANY OTHER TYPE as it may corrode the radiator.
Once you get all these items in order, you will enjoy a smooth and rewarding ride.
Good luck!

Sergio
'95 E320 170K miles
'99 ML430 89K miles
'94 C280 138K miles (R.I.P)
 

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NeoWeird said:
It has VERY sluggish pick up, maybe a 2 second delay before any acceleration takes place from a stopped position, however once in motion it seems to respond normally. It also makes a low popping noise when in lower gears/speeds. It doesn't follow any pattern I can tell, and it only seems to last until late second gear/early third gear or ~30 mph (it's an automatic so it's hard to distinguish exactly where it lets off). It has also been running somewhat rough lately.
Did you ever resolve the sluggish acceleration problem? I'm having the same symptoms with my 95 C280.
 

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Jacob,

You sound like you know just enough to be dangerous under the hood( might do more harm than good). I would take it to a more knowlegable person.

#1 Let me impart a little wizdom, valves don't miss fire, spark plugs do

#2 The copper washer is for the oil drain plug, you need to replace the old one with a new one once you drain the oil. Do not reuse the old one

#3 the poping sound you are hearing is probably the engine misfiring. This could be due to a few things (1, spark plugs), (2, bad air mass sensor) which would cause the engine to run too lean and evetually misfire. This also could explain the sluggishness you're experiencing. I would go to pep boys and have them hook the car up to a code reader. That should narrow your search.

#4 I am guessing you have the straight six and not the V6 engine since it's a 94 MY
common problem with these are head gasket, wiring harness.
 

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How to change spark plugs 2000 c280

I have 2000 c280. I am attempting to change the spark plugs for my car.
I can't recognize where the spark plugs are and I don't know how to remove them.
Please let me knew where they are (if possible, include the fic.) and how to change them. thanks!
 

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Amethyst 2001 C320 with 345,000 miles
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Hi Kevin,

I have a '94 C280 so I don't know if the engines are similar, but there is a plate on the top of the engine secured by allen screws that needs to be removed, in order to reveal the spark plugs. The plate runs the length of the engine and sits right on top. Good luck!
 

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I have a 95' c220 and have had the same kind of knocking noise in lower gears and also the sluggish behavior. I replaced my air mass sensor and they both went away. (first post)
 
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