I purchased a 2000 S500, W220, in 2005 with 80,000 miles. Now have 108,000
It has seen the repair shop for various items.
I would like to start taking care of some these issues myself, if possible. Or at lease understand what is wrong and what they are doing to fix it.
I currently have these issues:
Front Brakes Squeak – about 100% of the time when backing up they squeak when you stop. About 50% they squeak when you stop at stop lights. I was told that the rotors are not flat, like a little wave in them and this is causing the squeak. They stop fine. I was also told, MBs do this. The rotors and pads were replaced about 1 ½ years ago, so they won’t warranty it. ( I have not pushed the issue with them yet ). Is there anything that could stop or minimize the squeak?

Check Engine Light, P0301, Cylinder 1 Misfire – If I accelerate hard or get the RPMs over 4000 the check engine light comes on. I have read the codes, they would/could read, P0301, P0306, P0307, P0308, P0300. The last few times I have done this, it has only been P0301. The car will then run like crap. I pull off to the side shut the car off and erase the codes. The car will then run fine. It’s not often I need to accelerate hard, but if needed I want it. I have read that the Mass Airflow Sensor could be the cause, but this was replaced at 90,000 miles for a Check Engine Light error then. I thought about cleaning the MAS per other post with contact cleaner, but wanted to get others input. Are there other meters to read other codes on MBs. What else could cause this to occur only at 4000 rpms?

Auxiliary Fan, Control Unit – A few months ago the Radiator Fan was make some noise. While in the shop for oil change, they said the Auxiliary Fan Assembly need replaced for $1200. I checked it out myself and found that it was only the electric motor going. It appears that you can only purchase the complete assembly. I took the motor apart, and could only replace one bearing. The other bearing is on the end with the pullye, and it looks like its molded together and I can’t get it apart. So, I searched the Internet, and found an aftermarket AFA for $350. Took that motor off and used it. This works fine. It appears that the Auxiliary Fan Control Unit stopped working. also Why? I tested the AFCU with my voltmeter and it had 12v in, variable control voltage in, but 0v out. It appears this shorted out (stuck open). I beat it with my hammer, but no help. I have not opened it up yet. Has anybody done this? I currently have the motor connected to a relay. Now the fan runs all the time, at 100% and it’s loud, as in airflow loud. This really moves the air. I located a new AFCU, but $170, ouch again. Is it common for the AFCU to go out also?
Danger note: I connected the relay to a fuse that was 12v only when on. Mistake was not knowing what the fuse did. While I was driving 65mph the car shut off. I safely pulled off the road and seen the fuse that I tapped into was blown. Replaced the fuse, move the relay 12v to a different fuse, this one is working fine. On the relay I do have the 12v for the fan connected to the fans 60amp fuse. This is just the 12v control voltage.

Air Shocks – Just wondering if other have this issue. Last winter it got cold, minus 30. The car was parked outside and when I went to work the car was bottomed out. Looks like the shocks lost all of their air. I start the car and it report an error about it. I waited for the car to warm up and the shocks filled up.

Drivers Mirror – My wife broke the driver's side mirror off while backing out of the garage. $1000 to have the dealer fix it, I glued it back together, replaced the mirror with a standard mirror. It looks fine, but the motor was also damaged. You have to manually adjust the mirror. I would like to locate a complete mirror, but can’t. Anybody know where I can get one?

Rust – It is starting to show some signs of rust on the car. On some of the door handles, bottom corners of the doors, bottom center of the truck. It’s not to noticeable, but I have not seen this on other MB’s, even older than mine. Suggestions ???

Front windows squeak - Everytime you "roll" the windows up/down they squeak. Another post suggested to wax the outside. Does this help or hurt?

We love our S500, but not the repair cost.
Thanks, Todd

 

First, congratulations on the quality of your first post. Makes me want to answer more than my knowledge permits. Welcome to the forum!

Brake squeal is addressed several times on the forums - both on BenzWorld and here. For one such post, see http://www.benzworld.org/forums/w220...t=brake+squeal - but do a search, you'll find more - perhaps something more helpful.

I can't help with the engine problem. The Mass Air Flow sensor exhausted my best guess.

I don't know enough about the fan problem or its control unit to answer.

There are many, many posts concerning Airmatic on both BenzWorld and here. At least one deals with the cold weather problem you describe. My best guess would be a frozen Airmatic relay, perhaps coupled with some seal shrinkage or stiffness during the cold weather (thirty below is pretty cold, as I know all too well). If the system leaked, the ride height sensors should detect it and signal the relay to flip on. This didn't happen.

Consider replacing the relay before weather turns cold again (they sell for about $80; some dealers charge more; see posts on airmatic relay prices on the forums) - and check your system for leaks (spray soapy water at the upper mounting points on the strut towers, and around the bottom of each strut; look for bubbles).

I would try ebay or a junkyard for the mirror; you may have to paint the shell. Contributor vovpar has recently parted out a w220 - you might PM him.

Check with your dealer on rust warranty. There have been some posts on the forums, but I haven't bookmarked them. The warranty may only go to 100K miles - I don't recall. But if the rusty areas were original paint (not repainted because of damage), some have had sucess gettting it fixed.

Window squeak: There have been posts concerning adding velour or felt, but again I don't have it bookmarked. A search may find it. Likely the squeak is from old weatherstripping.

PS - some years ago I lived in a town with a gas stations named "Terrible Herbst." Not related, are you?

 

Thanks for the feed back.
I will investigate your posting.

I wish. There are Herbst casinos in Las Vegas that I have been to. They said, "sorry no family discounts".

 

i would like to say welcome to the life of owning and mb. these cars drive great when taken care of properly but if its not serviced or maintained it will cost you heavily like it is now. i say get a whole car inspection from the stealership.

 

I finally got tiered of the brakes squeaking and P0301 issues.
I swapped the plugs, coil, and wires from Cyl 1 with Cyl 2. The 301 was still there.
I then took it to my local Midas. They fixed the brakes by turning the rotors and putting on new pads. This was the easy part.
For $40 they said they would diagnose and the let me know on the 301.
The tech, smoked the engine for vacuum leaks, did not find any.
Checked the fuel injectors, and did not see anything wrong.
Checked the fuel pressure, and it was within spec.
So, he did a fuel injector cleaner and fuel system cleaner.
I drove the car for a week, and the 301 error was still there.
The tech check a few other things out and decided to replace the Bosch plugs with NGK plugs. Just the standard plugs (7090), not the $12 ones. To find out if the plugs were the problem.
This did not fix it either. He left the NGK plus in and said that they could not find the problem and I would have to take it to a MB service.
Not bad for $40, but I still have the problem.

Any suggestions before taking it the MD Dealer.

Thanks, Todd

 

why dont you have warranty?

If you had Warranty, all this would be covered..

Most important thing I learned on this forum from all the users: If you wanna own a S, you must have Warranty.

 

Lot of people have this problem, and it drove both the driver & tech crazy, since the P0301 often triggered by different cause. From what I am told, people go from MAF, to wire, to spark plug, to injector cleaner..... You could take out a mortgage on a repair, and the code still there

Guess what's often caused it, after a zillion dollars is spent on other repairs ? Either the cat or the EGR valve is plugged

Ask the Midas person to do an exhaust backpressure test for you.

Also, if you need any used part for your car, call this number: 323-221-3126 , they have part for most of the late model Mercedes/BMW. Their junk yard is filled with late Mercedes model (lot of W220 S class there), I even saw a W221 there !!

 

This weekend I used MAF Cleaner and it helped, but did not solve it.
At about 3500 RPM I could hear a change in Air noise, but the CEL did not come on. It sounded like it not getting enough air. (I could be wrong).
Later that day, did the same thing, about 3500 RPM, same sound, but the CEL came on with 301, 306, 300.
In idle at 3500-4000 it ran fine, no CEL or sound change. (I know, no load)
I then tired driving in 1st/2nd gear and sometime the CEL would come on at 3500-4000 and some times not.
I have scheduled an appointment with Midas to check those items.

Thanks, Todd

 

Midas may have done about all they can. Your dealer, or independents with proper MB troubleshooting equipment and experience, may be necessary at this point.

 

To see if it's the MAF, the easiest test is to unplug the MAF (don't worry, it will not trigger the CEL), and drive around. If you have normal power, then it's the MAF, else, it's something else.

The only thing happen when you drive with the MAF unplugged is the car running a bit rich, but that's all.

 

I have done dozens of brake overhauls on MBs and BMWs and it is quite possible that the stationary pad was not installed with some of the anti-sqeak goo. This stuff is magic - just be sure to spray down the caliper surfaces with brake cleaner so the stuff sticks.