Engine light came on and dealer replaced magnets??? What are they talking about?
Thread Starter
MBWorld Fanatic!
Joined: Sep 2007
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From: Southeast
2008 C300 Sport, RWD, US
Engine light came on and dealer replaced magnets??? What are they talking about?
Over the weekend, the engine light came on in my C300.
This morning, I took it to the dealer to find out that it had something to do with magnets on the cams (of which there are 4 of) that control the valve timing. Apparantly 3 of the 4 of these magnets were replaced. I asked why they didn't replace the 4th one as it was pretty obvious that its time is short, and the service rep didn't know. I guess they're not allowed to replace what's not yet failed.
The CSR said that these magnets have something to do with valve timing which causes either a lean or rich mixture to occur if the magnets don't work.
Does anybody have any idea how that system works? diagrams maybe?
Also, I don't abuse my car. Why would these magnets go bad?
This morning, I took it to the dealer to find out that it had something to do with magnets on the cams (of which there are 4 of) that control the valve timing. Apparantly 3 of the 4 of these magnets were replaced. I asked why they didn't replace the 4th one as it was pretty obvious that its time is short, and the service rep didn't know. I guess they're not allowed to replace what's not yet failed.
The CSR said that these magnets have something to do with valve timing which causes either a lean or rich mixture to occur if the magnets don't work.
Does anybody have any idea how that system works? diagrams maybe?
Also, I don't abuse my car. Why would these magnets go bad?
Super Member
Joined: Dec 2007
Posts: 648
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From: Seattle
C-300, XC70, Wrangler
How many miles? At just over 20K miles, I had to have the Exhaust Cam Sensor replaced. Sounds a lot like the problem you had ... magnets.
I don't know why they would go wrong. If they're permanent magnets, they should be fine, unless something is reversing the polarity?
I don't know why they would go wrong. If they're permanent magnets, they should be fine, unless something is reversing the polarity?
Newbie
Joined: Mar 2009
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1992 Jeep Wrangler
You probably had a code for continuous camshaft adjustment. The cam adjuster solenoids (magnets) become oil fouled. There are 4 of them, 2 intake and 2 exhaust. MB is replacing them with a new part number. They will only replace the magnets that set a fault code.
Thread Starter
MBWorld Fanatic!
Joined: Sep 2007
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From: Southeast
2008 C300 Sport, RWD, US
skinny,
Since MB is replacing them with a new part number, can we presume that they know they have a problem and are replacing them with something better?
Since MB is replacing them with a new part number, can we presume that they know they have a problem and are replacing them with something better?
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From: Sweden
S213
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MBWorld Fanatic!
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Thread Starter
MBWorld Fanatic!
Joined: Sep 2007
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From: Southeast
2008 C300 Sport, RWD, US
Vic,
Is it very likely that all three magnets would go out at the same time?
I'm wondering if it took the third one going out to get the engine problem dash light to illuminate. If that's the case, I'm concerned that the 4th magnet will go out and not activated the engine problem light.
Is it very likely that all three magnets would go out at the same time?
I'm wondering if it took the third one going out to get the engine problem dash light to illuminate. If that's the case, I'm concerned that the 4th magnet will go out and not activated the engine problem light.
Member
Joined: Mar 2009
Posts: 139
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From: Carlsbad California
C350 and a Lightning.
They are cam position sensors and I would think that one going bad would give you a check engine light. one would throw a code. And I'm surprised that one wouldn't effect driveability if not cause the engine to stall.
Maybe they are redundant and you only use one intake/exhaust? Somebody know this?
Maybe they are redundant and you only use one intake/exhaust? Somebody know this?
Thread Starter
MBWorld Fanatic!
Joined: Sep 2007
Posts: 1,481
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From: Southeast
2008 C300 Sport, RWD, US
Only one time about a month ago when I exited the interstate and came to a stop at the bottom of the exit ramp, the engine loped, but when I got moving again it disappeared not to be seen of again. Otherwise, once the engine warms up its always been very smooth.
Does this provide any clues?
Does this provide any clues?
Super Member
Joined: Dec 2007
Posts: 648
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From: Seattle
C-300, XC70, Wrangler
Okay, I'm a wee bit confused. When the CEL came on, the manual (I stopped and looked it up, sitting in a forest glade ... ) said that I should drive the car to the nearest MB dealership for repairs.
Well, here's the confusion: what does this sensor control (ECS or ?)? Does it have anything to do with something that would cause great damage inside the engine? Or is it strictly fuel mixture, etc.? The manual said something about fuel quality, or the catalytic converter. I know the CC can be expensive, but I'm worried about damaging the inside of the engine.
And, does the CEL serve double duty? Is there ever a time when what it indicates should cause you to have the car towed?
Well, here's the confusion: what does this sensor control (ECS or ?)? Does it have anything to do with something that would cause great damage inside the engine? Or is it strictly fuel mixture, etc.? The manual said something about fuel quality, or the catalytic converter. I know the CC can be expensive, but I'm worried about damaging the inside of the engine.
And, does the CEL serve double duty? Is there ever a time when what it indicates should cause you to have the car towed?
Newbie
Joined: Mar 2009
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C230 Sport Sedan
I've just run into the same Cam Magnet problem. The diagnosis so far has them replacing the ECU, the wiring harness, the Oxygen Sensor and the Catalytic Converter for about $7000. My research has produced one document of interest regarding emissions related parts in the US: http://www.epa.gov/OMS/consumer/warr95fs.txt. The EPA requires warranty repair of all emissions related systems for 2 years/24000 miles and major systems (ECU, CC) for 8 years/80000 miles.
Senior Member
Joined: Sep 2007
Posts: 366
Likes: 1
2008 C300 SPORT (white)
actual recall
I just left the dealership today, had to drop mine off for the CEL, come to find out that this problem is an actual recall from Mercedes-Benz. So for those not tracking this, might wanna get yours replaced. the Cam Sensor Magnets, that is.
MBWorld Fanatic!
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From: Long Island, New York
2013 C300 Sport Black Darth V3.0
Mine is in right now because the CEL came on. Haven't heard from the SA yet so I don't know what the cause is. Got a 2010 as a loner, don't really like the new side mirrors they are so small.
Super Member
Joined: Feb 2010
Posts: 757
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From: LI, NY, U.S.A.
2013 GLK 350 4M (Iridium Silver), 2010 E350 Coupe (Iridium Silver)
I bet this fixed that
edit: I do admit I like the big mirrors though. Drove the e coupe for a few days this week and despite the lack of a b-pillar, I couldn't help feeling like the blind spot was huge.
Senior Member
Joined: Sep 2007
Posts: 366
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2008 C300 SPORT (white)
I was orginally told the same(Bad Seal), when I took the car in, but once I went to pick up, they told me about the magnets. That there was a recall on them.
