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B Class Common Problems and Their Solutions

488K views 347 replies 85 participants last post by  DEVOURS 
#1 ·
Howdy,

I've created this stickied thread so that you can post links to threads about common B class problems, and their solutions. This will help us keep the top of the forum from getting cluttered with stickies, and will also be a great resource for new members here at Benzworld.

Cheers,
Chris

Here are a few:

http://www.benzworld.org/forums/w245-b-class/1323817-check-your-oil-level-now.html
http://www.benzworld.org/forums/w245-b-class/1322934-rust-problem-all-b200-bonnets-revised.html
http://www.benzworld.org/forums/w245-b-class/1343957-rust-disc-plate-rear-brake.html
 
#57 ·
(coles notes: anyone with occasional short duration i.e. half a second rough idle or stumbling while warm and idling?)

Greetings to all B owners/drivers.

I should point out my expectations of Mercedes are quite high, considering a family owned '83 W123 and '98 E200K.

Having said that, after owning the B for maybe 2 months, we're pretty happy with the car, a 2008 B200 with about 19k on the odometer.

Couple of issues:

1. Rust - just a little bubbling on a couple of the doors at the bottom on the inside, just above the sealer they put after welding. Looks more like an air bubble, very soft, narrow, but maybe an inch long. Common problem as mentioned in this thread. Will keep my eye on it.

2. This one I need you guys/gals to chime in. Yes, I'm picky, but when the engine is warm and idling, once in a while (maybe every 3rd or fourth stop at a light, idling for a minute) the RPM's stumble very slightly (~20-50RPM's) for about a 1/4 sec. A/C and accessories off, no change in steering wheel or any other inputs. Almost seems like the computer is playing with the mixture, looking for any adjustments needed, maybe for fuel economy or emissions. BTW, we use Top Tier premium fuel, usually from Shell or Petro Canada or Husky. Heard a few bad things from Esso, but they're now top tier also according to the site.

3. BTW, keeping the rear rotors clean with some slightly heavier braking every once in a while. I do notice the front pads produce a lot of dust, though.
 
#58 ·
#2 is the same with my car. My 1966 Peugeot with Kugelfischer fuel injection NEVER does that, so I too wonder why the B does this. Just annoying/surprising. Doesn't run any deeper than annoyance.
 
#61 ·
I've yet to see any change in the idle, and that's from 2005, but maybe I'm not watching closely enough. I will start to watch.........

Any small bubble on the lower seam of the doors etc. is indicative of a much more serious corrosion issue along and under that seem. Many here have had the doors changed with exactly the same bubble. It probably takes a little prodding to get the doors changed, or getting the regional rep involved. This is a very well documented problem for Canadian B's.......
 
#62 ·
The rusty doors should be well documented problem, but when you call MB, they act like this is the first time they've heard of it... I'm still dealing with my "rust" issue since November last year. Just for the fun of it I should post some pictures of what the doors look like now.
 
#64 ·
Someone told a forum member that coming to these forums is like going to a hospital. All you see are problems. So I'll chime in with some good news.

I have a 2008...it does have a tiny bit of bubbling (as I mentioned a few posts above), but overall I'm very happy with the car. Had an emergency brake and avoid deal a few weeks back, to avoid a left turner turning in front of me at the worst time. Car responded amazingly.

Anyways, no evidence of rear brake rust so far, lol, maybe related! And the (#2 in post mentioned) slight rough idle seems a bit better after the last service. Had them check for updated ECU programming and such.
 
#66 ·
Hi everyone.
I am hopefully a future B Klasse owner. I am interested in buying a 2008 B200CDI and I really like the car from what I have read online. I have not tried any so far but B Klasse satisfies my needs as far as the comfort etc.

I don't have much to say but that I am very positively surprised with everyone's "complaints". I mean lots of squeaky sounds are pretty much only problems you guys are complaining. This is very acceptable for me as I have also considered Golf Plus which has multiple engine/transmission problems for 2.0TDI engines and it will keep some resale value unlike some french (Scenic, C4 Picasso) "competition".

I have noticed most of the users here drive B's with petrol engines.

Does anyone have any remarks regarding B200CDI or is B180CDI a better choice ?

Thanks
 
#68 ·
Poster said B-Klasse, so I'll say from a German speaking country, first name Emir? Yes, please add profile info and a sig. with name. Makes this a closer community.

First thing...you need to drive it and tell us what you think. That's the best way to judge a car. Also, there are much bigger problems than squeaks, but every car has problems, and since you mentioned VW, you know it can be much worse.

Now go drive one. For its class, I think you'll like it overall.
 
#69 ·
Fuel Gauge and check engine light issues

I have a 2006 B200 with 143,000 kms, manual transmission. The fuel gauge has a mind of it's own quite often. When I turn off the car, the fuel gauge does not return to the normal off position, and the reading on the gauge when the car is running is not possible - the needle is often pointing straiight down on the far right hand side of the gauge. The check engine light also comes on and goes out quite randomly. There does not seem to be any connection or sequencing between the two issues. Has anyone experienced either of these issues? I live about 2 hours from my dealership and if there is something I can do to fix it - I'm all over it! Thanks!
 
#70 ·
Not sure where you are (please add car info and location to your profile), but if there's a local car parts place, get an OBDII scanner and tell us what the code is.

Could be related to the gauge, but probably not. Sounds like the gauge is faulty internally.
 
#72 ·
SRS warning light issue and Wipers not working - Solution

I looked through these forums to find a solution before and couldn't find one to fix the Wipers and of course the cause of SRS warning on a 2007 B200

This is what the mechanic said after 3 hours of labor.

- Found no power supply to the Wiper system circuit (the fuse didn't have any power).
- After inspecting the wiring of the fuse box, it was determined that the SAM module wasn't supplying power to the specific circuit on the fuse box. Found a faulty relay switch on the SAM unit.

The relays for the fuse box and the wiper relays are on the SAM unit that link to Fuse box. The SAM unit (with relay switches) is located behind the glove compartment. If I had known that I could have replaced it myself for $8 and took it to the mechanic to clear the code for $50. It seems like relays on Mercedes are defective.
 
#79 ·
The SAM unit (with relay switches) is located behind the glove compartment.
Hi, I'm trying to find where the relays are located. Do you mean they are inside the glove compartment? Or in the footwell behind the glove compartment door? I tried removing a panel in the footwell in a UK spec car and couldn't find anything. Thanks
 
#74 ·
My car goes in for service tomorrow and the no-start problem recurred yesterday. That's one of the items they'll be handling again under extended warranty. Held the key in the "start" position until it started, which took 5 seconds (for the starter to engage). Could be a faulty SAM.
 
#75 ·
.... the no-start problem recurred yesterday. That's one of the items they'll be handling again..............

.... Could be a faulty SAM.
Why is it that a few B's here are endlessly problematic..?..and some others (like mine) have yet to have a hiccup "so far"... It's almost 7 years in my case...Can it be as simple as 'a roll of the dice' when you buy one..??......
 
#78 · (Edited)
Yup and the 2006-2008 models do not have separately interchangeable starter relays, only post-2008 models do. The fix for a starter relay fault in the older models is a new SAM. It's going to be over $1000.

I think that my car is probably not the best example M-B made; however, it has double the km of DEVOURS car, so a lot of us with the higher km will experience component failures sooner in time than lower km examples.

But I think that there is some commonality of the starter relay issue (many people here have had this) and in fact I woud speculate that the SAM was redesigned for 2009 to have a separate starter relay because of some early indication that the earlier cars had some bad relays.
 
#82 ·
hi everyone,

I am new to this site and I currently own a 2008 B200 Turbo with 41 000km on it. Recently, the engine light came on and I went to the dealer for a check up. They are telling me my turbo does not work which causes the engine light going on. I have to change the whole turbo thing because the turbo is not working anymore and I am loosing power but it would cost 3000$ CAD for the parts plus maintenance and all it would go up to around 4500$ CAD. They are also saying that because I don't drive the car enough which causes this problem. Is that true?

Did this happen to somewhere else here ? Can I let it on and not change anything ?

Thanks everyone
 
#83 ·
Welcome aboard "mister p"

Tell us "where you are at" and maybe we can suggest a local MB repair shop for a 2nd opinion.

Maybe a scrap yard can find a used B 200 turbo for you. Put a bit more info in your "profile" to help us here...

A bad turbo is not good news ....41,000 is very low for the Turbo to go bad.. Having good clean synthetic oil is very important for the life of a Turbo. Not using the B very much should not affect it other than seeing rust appear on the rear rotors. Now parking it for many months would probably kill the battery though.
 
#84 ·
...not to mention, letting the car idle for 30 seconds before shutting down....more time is needed if the turbo was working hard.
 
#85 ·
What are the symptoms you are having? I had my diverter valve replaced recently that was causing an intermittent loss of boost. When my indie shop scanned the code, that's what showed as the problem, it was replaced for $150 or so and is working fine ever since. I guess if the dealer scanned it and that's what it said, then it must be the turbo.

Anthony
 
#86 · (Edited)
Don't believe the dealer.
They are all about making money by throwing new parts at the problem.
They will over charge for time spent on the repair and full price for parts 'cause that's how they make money...get an indy to look at it.
The dealer is the LAST place to take it for repairs if it is out of warranty.
I am south of Toronto and can tell you some real horror stories about our local dealer and how they have caused more problems then they solved and then lied about it.
NEVER NEVER take an out of warranty car to the dealer..NEVER !!!
The chances you need a new turbo are VERY unlikely.
It is most likely the boost control value.
Tell us where you are and someone can recommend a trustworthy indy.
 
#87 ·
Mercedes are writing a letter to explain known rattle?

Hello

Mercedes are writing a letter to explain known rattle, and also re writing a warranty if it leads to problems but, they still don't actually know what's causing it.

There is a odd resonating sound when accelerating between 1700-2000rvpm from under the car bizarrely, occurring only on some 2009-2010 B160 petrol manual B-Classes i have driven.

It sounds like it's originating from the engine or exhaust. I'm told it may be the exhaust box or baffler needs realigning/tightening. The word rattle or grinding best describes it when accelerating after a gear change.

The odd thing is, it is present on 3 out of 4 B classes i have driven and has varying degree of severity, indicating it did not leave the production line with it present. It could be occurring on your car too, so has anyone noticed this annoying sound from under the car???

I would love to hear from someone on this as i cant find any info on it or other reports.

Regards
Jon
 
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