Simonas.st

Hello,

I have changed balance shaft and chain roughly 4 years, and 100000km ago.
Now check engine light came recently.
Local guy with STAR has checked and diagnosed, that it's both magnets on the right side. I didn't trust that conclusion.
Went to authorised MB dealership for diagnostics, and asked to tell me error codes. Guy told me, that he will not give me codes, but will tell me what to do.
After diagnostics, he told, that it's probably stretched chain, as camshafts working according to specs, when at idle, but losing timing, when given rpm.
Being non believer, I've checked timing on cams myself threw position sensor holes, it looks fine.

How could chain stretch in 100k km, when I drive like an old man, once a week?

Are there any other possible scenarios?

Thanks.

boardboy330

It is possible the magnets need replaced.

MBENZTECH

Most likely your magnets need replacement..... I have never seen a stretched chain on a M272/M273. Get yourself a pocket code reader.

Simonas.st

MB dealership told me, that according to buletin, magnets with part number A2720510077 should be replaced with A2720510177. So in my case, magnets couldn't be culprit, because it's newer version of them already installed in my car.
That's them talking, I never trust them. If it's BS I don't know.

Sal_Monella

The iCarsoft MBII is pretty reasonable (under $150 USD) and cheaper than a single Indy or Stealership ripoff.
The Star Diagnostic unit is best but pricey.
Best to go in knowledgeable, it deters them from trying to rip you off.

Simonas.st

Yes, I understand that I need diagnostic tool myself. Especially now, when I've added to my park w220. I will go for Star C4. But that will take some time.

I would like to hear, guys, what's Your take on magnets reasoning of my dealer? BTW, is it possible, that both magnets fail on one side of the engine, at the same time?

Simonas.st

Hello,
Since no other opinions were shared, I've ordered magnets. When I will change them, do I need star to delete engine check, or it will go by itself?

Simonas.st

Changed magnets, nothing has changed.
Do I need STAR to reset engine check light? It used to go out by itself before.

ANOTHER interesting thing, which I suspect could be the real culprit is some kind of bogging when engine idles. It's not rhythmic, comes like in 10-15 second intervals. When I had airfilter box removed, I've noticed, that it's louder and higher sound and it comes from MAF sensor hole.
For me it sounds like misfire, but STAR doesn't show any.

Any help is much appreciated.

Simonas.st

Any input regarding sound from MAF would be nice.

Do I have to put it as a new thread?

knowbenz

You need to process whatever fault codes are in there. Without proper diagnosis your going to be making guesses again.

Simonas.st

I'm about to order Icarsoft MB II. Is it any good? Or should I choose something else?

knowbenz

Never used it, only factory scan tool. If you have cam position codes you need to be able to actuate the cam magnets while monitoring the values. any scan tool would be better than guessing though

Shadly1

I have it. It reads a LOT more than my OBDII scan tool and can reset most service indicators. I can't compare it to the factory scan tool but I don't have those kind of dollars...

Simonas.st

Thanks. I will come back later with trouble codes.

Simonas.st

So trouble codes are:
1208 (P0016)
1200 (P0017)

I've read, that could be magnets related, but magnets has 01 number, as per buletin, and for diagnostic purposes, I've changed one with brand new couple of months ago, so ruled out?

Any ideas?

Agent-A01

Have you tried replacing the crankshaft/camshaft position sensors?

Simonas.st

Not yet. I've found on mercedesmedic website, it should throw different code if that would be the case.

Does anyone has experience with it?

artim808

1200/1208 indicate balance shaft failure. Did you had balance shaft replaced with new part?

Simonas.st

Yes, it was around 100000km 6 years ago.

Simonas.st

One thing is not adds up to balance shaft problem.
I've watched this video: and my cams are in right position.

knowbenz

Did you check looking through the holes or taking off the front covers?Check freeze frame data and see if the faults occur while cranking. or after the vehicle is started. Either way you can monitor actual position of cam gears hooking up a four channel scope. Both intakes should line up and both exhausts should line up. You can monitor while cranking and at idle.

Simonas.st

I have checked looking through the holes. But now I'm thinking about taking off front covers, even timing chain cover if it is possible without removing the engine.

I looked at amazon, that four channel scope is starting from 350usd, a bit pricey.

Dealership checked with star and told me, that on idle it shows 0 cam misalignment, only when throttled up. That in their logic proves only one thing- stretched chain.

Could You please tell me, how to check cams by taking off front covers?

knowbenz

In that video you posted it shows you.

Simonas.st

Yes, I've forgot about the second part of the video.

Does it make sense, what dealership told me about cams are in synch on idle, only out of alignment when throttled up? If they are right, my checking makes no sense.

knowbenz

I don't know how they are checking so hard to say. All the ones I've seen will show off at idle or any RPM. Sometimes with bad cam adjusters you may only see it cranking. as the cam will go back and forth while cranking if that makes sense. On freeze frame data it shows faults occurring at around 200rpm. You likely have stretched chain or worn sprocket.