Mercedes-Benz Forum banner

Camshaft Solenoids AKA Cam Magnets

69K views 97 replies 23 participants last post by  rudeney 
#1 ·
Purchased my 2007 CLK350 Cab last spring. Last month the Check Engine light came on, so I visited the dealer. He said 2 of the Cam Magnets needed to be replaced, and because I have an extended warranty, he recommended that all 4 be replaced. Shortly after the service was completed, we took a trip and put 1500 miles on the car, without any additional problems. My question is "what are the cam magnets for and since the light went out after two days before my visit to the dealer, was this service really necessary?"

Other than that, the car has been great and rides much better than the Corvette it replaced.
 
#2 ·
Rather than 'magnets', a better expression is 'camshaft solenoids'. Your CLK 350 has engine M272, which has VVT (variable valve timing).

To achieve this, the camshaft timing is adjusted (while the engine is running) from the ECU by means of the camshaft solenoids which incrementally rotate the shafts. There are 4 altogether.

The operation is explained in more detail on the WIS page below:
 

Attachments

#7 ·
This is your car.

VEHICLE TYPE: Car
MODEL NAME: CLK 350
ENGINE: 272960 30 464580
TRANSMISSION: 722906 00 871208
FRONT AXLE: AL066060803127
ORDER NUMBER: 0771518492
PRODUCTION NUMBER: 3016968
INTERIOR COLOR: 801A
PAINTS: 197U
RETARDER: 8 060911
DELIVERY DATE: 11/09/06
PRODUCTION ORDER REFERENCE: N
RELEASE DATE: 11/09/06

242 FRONT SEAT RH ELECTRIC ADJUSTABLE WITH MEMORY
249 AUTOMATICALLY DIPPING INSIDE REAR VIEW MIRROR
264 LICENSE PLATE ATTACHMENT AMERICA
265 LINES-NO.PLATE DISCONTINUED
275 MEMORY PACKAGE (DRIVER SEAT, STRG. COL., MIRROR)
427 AUTOMATIC TRANSMISSION 7-SPEED
461 INSTRUMENT WITH MILES IND. AND ENGLISH LEGEND
494 VERSION FOR USA
524 PAINTWORK - PRESERVATION
551 ANTI-THEFT/ANTI-BREAK-IN WARNING SYSTEM
581 AUTOMATIC AIR CONDITIONER
634 DELETION - FIRST AID KIT
636 DELETION - WARNING TRIANGLE
668 PACKAGING FOR SHIPPING VEHICLES WITH TIE-DOWN HOOK
673 HIGH-CAPACITY BATTERY
731 WOOD TRIM BURRED WALNUT ROOT
740 BLACK SOFT TOP FABRIC 9001
810 SOUND SYSTEM


Oh man... Your engine is in the batch that might be affected by the well-known balance shaft problem... :( Ie, Equipped with M272 Engine Up to Serial No. 2729..30 468993.

Read other posts on this issue in the archives. All are based on this MB TSB:
 

Attachments

#9 ·
New to this forum. Any help would be appreciated.

Have 2008 CLK350 VIN WDDGF5EB5BA513834 with two outside camshaft solenoids leaking oil....my service tech discovered them before any code appeared.

Still under warranty...should I request all 4 be replaced? Warranty expires end of month.

Odometer reading is 8300 miles

Is this also the same M272 Engine referred to in this thread and if so does it fall within the serial range of troublesome units that may be candidates for extended warranty?

Thanks for any advice
 
#10 ·
That's not a valid VIN. Check and report and I'll look it up for you. Just guessing, being a 2008 model and a 500000 series VIN, I doubt it falls within the balance shaft range problems. On the cam sensor magnet issue, it's the dealer's call. Typically, they won't replace parts like that unless they can verify a problem with it.
 
#12 ·
Rodney thank you...correct VIN is WDBTJ56H38F241319 (my error, other was off loan car doc)...hopefully this vehicle falls outside problematic engine range...if not any thoughts on warranty extension...anyone care to suggest a provider?....research indicates some warranty extensions are not worth paper they are written on......the vehicle is low miles, we follow all service guidance and tend to keep our vehicles longer than most
 
#13 ·
OK, that's engine #733654 - way, far out of the bad range. :thumbsup: Personally, instead of spending $3k+ on a good extended warranty, I'd put $3K in the bank (or under the mattress, whichever is more convenient) and save it for the repairs you may need.
 
#16 ·
As an update on the camshaft solenoids issue and then a bit of a vent......the car was still under warranty soon to expire. We patronize a local independent. (excellent). I asked them to inspect the car for possible warrantable issues we should address before the warranty ran out. They found the two flawed camshaft solenoids and pointed me to the dealer for repair. Armed with the information including which two were leaking I dropped the car at the dealer and asked them to go over the car and to specifically address the two offending units. The dealer called later to say there were no detectable leak. After reading this board and speaking to the Indy I learned that these things leak internally into the wiring (someone described the harness as behaving like a "wick" so external leaks may not be obvious). Armed with this additional info I called the dealer and asked the dealer to look a little harder. They weren't happy but after bringing the service writers manager into the discussion they miraculously found both units were leaking (internally) and replaced them.

My original migration to an independent was prompted by a similar experience a few years back. The 300E had a small diesel leak. The service writer wanted to Re and Re the pump (1100 dollars). I offered to pay time and material for a mechanic to diagnose and repair the leak in hopes that the pump did not need replacement. The service writer would not hear of it...started quoting company policy etc...

So went on line, found this board, found references to small seals that tend to break down when exposed to certain diesel additives....found a well recommended Independent from this board. The Indy was happy to oblige on time and material...fixed the problem for less than $150 and at the same time discovered an issue with a loose belt tensioner (which had very recently been replaced by the dealer). It would have caused major problems had it not been tightened. Almost 4 years later, no leaks, and a fuel pump (and vehicle) delivering better fuel consumption today than when new in 1998

Lesson
...if your service writer and or mechanic don't know their stuff it will cost you.
...do your homework...this board is great
....talking to a technician almost guarantees a better outcome

I hope this narrative is helpful. thanks guys
 
#18 ·
Well that's a weight off my shoulders for sure! :) Thanks for the info.

I think I will look into replacing the selenoids. I shouldn't have any codes coming up since I just had my service B but when I start my car the rpm isn't stable for about 30 secs and then stabilizes (were talking something minor like varying between 2 bars on the RPM). I also feel the engine shake for a second at startup (again minor no weird sounds or anything).

Do you think these could indicate faulty sensors or a need for the magnets replacement?

Cheers
 
#19 ·
Searching and researching CLK's

I have found "CLK Maintenance / Repair / PPI Index" and many other posts here VERY helpful. Sure glad to learn all this before I buy, thank you all.

Am paying particular attention to 272/273 engines re: Balance-Shaft/gear and check prospects for engine serial number using the Russian VIN decoder (which once a while comes up blank). I know the upper limit of the bad batch of 272's is 468993 and for or 273's 088611, what's the lower? 000001? On the 273's?

These seem to be mostly 2006 and some 2007 models, am I right? I had read until after August of 2007, but am finding 2007's that check out ok. What's the general rule?

What can y'all tell me about the bad ECU on the Transmission Valve body. Not many carfax reports on the 2004-2008's I look at show them to have been serviced. Any serial number range or year models to look for here?

Sorry to be so windy, but there's a lot to look out for; sometimes I think "screw it, get a Lexus" and then recover. Thx, Donn
 
#20 ·
Am paying particular attention to 272/273 engines re: Balance-Shaft/gear and check prospects for engine serial number using the Russian VIN decoder (which once a while comes up blank). I know the upper limit of the bad batch of 272's is 468993 and for or 273's 088611, what's the lower? 000001? On the 273's?

These seem to be mostly 2006 and some 2007 models, am I right? I had read until after August of 2007, but am finding 2007's that check out ok. What's the general rule?
For the numbers for the affected engines, read the official MB DTB on post #7. No lower engine number is provided. Year of manufacture is not included either.
 
#21 ·
It would be worthwhile to pin down the date(s) of the inflection point(s) though. IIRC we kinda guessed at that August 2007 thing. I don't even know if the corrections were applied at the same time for both affected engines, hence the plural(s) above.

If we can figure out the approximate date(s) then we can post that info which is much easier for owners to compare with the Date of Manufacture on their cars' VIN stickers. Then only those owners whose DoM's are near the change will have to look up the engine number, etc. Everyone else will be able to tell at a glance whether their cars were built before or after the correction. This should result in far fewer VIN lookup requests
 
#22 ·
Russian decoder doesn't have this one...

Thank you for your replies, Marsden and Keyhole. Looking at 2 local cars in Dallas area, one a 2004 w/ only 46522 miles, VIN is WDBTK65G54T021963. A 2004 would have a 112 engine and 5 speed, therefore less problems right?

The other prospect is a 2008 w/ 88,589 miles, WDBTK56F38T088759.

Though one is before and the other after the problem years for balance shaft issues, Russian decoder comes up blank on both VINs and I'd like to run them.

Would either of the above cars be susceptible to transmission or cam magnet adjustment solenoid probs.?
 
#23 ·
This Russian VIN decoder site is still working for me:

Êàòàëîã çàï÷àñòåé Mercedes, ïîäáîð àâòîçàï÷àñòåé äëÿ Ìåðñåäåñ ïî àâòîêàòàëîãó.

According to that, the first car is a CLK 320 Elegance cabrio, with engine M112, and dark blue fabric roof. Delivery date 06/01/2004. (Post Valeo radiator problem) No balance shaft problem on this engine. 5-speed automatic.

Second car is a CLK 350 Elegance cabrio with engine M272, and black fabric roof. Delivery date 07/06/2007. Engine number 722906 01 250961 so built after balance shaft problem resolved. 7-speed automatic.

These are both fine cars - clearly the 2007 has the face-lift features (easy iPod, etc,) but the decision is yours....:)
 
#24 ·
Donn, that would be a tough choice for me. I shy away from high-mileage cars in general. Nothing lasts forever and various systems and components will need renewing/replacing. But the other car is 8 years old, and moreover my experience with 2004s is that they have a few more electrical gremlins than later models. My real advice would be to save up some more money to buy a low-mileage, late-model example.

Keyhole, do we know that engine numbers are sequential as VINs are? That would help us pin down the date of the shift. Remember (I'm sure you know) that model-year designation in North America normally shifts over at the end of each previous summer's production, which is why the 2008 model he's considering was built in July of 2007. I'd say that's one of the very first 2008s. But I seem to recall from an earlier thread that there were early 2008s with the balance-cam issue. Memory is hazy on that part though.
 
#25 · (Edited)
Mostly the Ru site works, once in a while not. Today it did and I printed both car's output, not only for reference but to let salesmen know I am not a complete rube. Another CLK I inquired about, OKC dealer sales guy pooh-poohed my transmission concerns. Guess what? Carfax showed tranny had been pulled out of car and worked on. Which might be good?

Is the 5 speed auto more reliable than the 7? I can afford newer than 2004, but almost think 2004's engines and transmissions might be more reliable (?). What's the consensus, if there is one?

Thanks again to both of you, this is a huge help.
-- Donn
 
#26 ·
Marsden - Sadly, I have no knowledge of the MB engine serial number system - ideally we need somebody who works in a dealership. They would have this info readily available.

RD. I guess that your bank balance (and how much you want to invest in your personal transport) have a bearing on your decision here. I faced a similar situation in 2006 when I was looking for a nearly new MB. Not for commuting to work - more as a kind of 'retirement present' to myself!

Over the years I have generally bought cars new, and held on to them for 5 to 8 more years, fixing problems on the way as best I could at home. But a new CLK was too much for me, and I eventually found a very low mileage two y/o (2004) CLK that was fully loaded and I bought it. My model has the M112 V6 engine and 5-speed tranny, and is now very similar in age and mileage to the CLK 320 that you have posted the details of.

If it is of interest to you, nothing has gone wrong with this car yet - apart from replacing my 3rd brake light (common problem) and 1 tail lamp. I'm on the 2nd set of tires and 3rd engine oil change. There is no sign of rust anywhere, and I live in a rainy country. With the benefit of the much lower price, I wouldn't worry about buying that CLK 320. Based on my own experience, if the service records are OK, it will not let you down!
 
#29 ·
Marsden - Sadly, I have no knowledge of the MB engine serial number system - ideally we need somebody who works in a dealership. They would have this info readily available.
Actually, a dealership would probably have no clue, either. You have to remember that the M272 and M273 engines were used in many different vehicles built in many different countries. And the balance shaft problem wasn't discovered until there were over 500,000 engines on the road. I'm not sure what VIN has the very last bad M272 or M273 engine, but you can;t make any date-related generalizations due to there being so many build schedules at so many factories. The only way to know for sure is to check the engine serial number based on the VIN.
 
#28 ·
414111 - That is within the affected range of balance shaft problems. Look out for MIL's with DTC's 1200/1208 (P0017/P0016). You might even want to ask about buying an extended warranty. Sometimes you can get them for a good price before the existing warranty expires. Talk to your dealer to see if they can help guide you.
 
#31 · (Edited)
another candidate, another question...

edit: Had [Have] found another possibility, a 2005 CLK500 with 55,000 miles. That means it's a 113 engine, so no probs. there, but it did [does] have the 7 speed.

a question remains: Anyone know if serial numbers can predict a Siemens VDO ECU transmission problem or is it all of them? What codes (OBD or?) should I be on the look out for?

Again, many thanks. -- Donn
 
#32 ·
I've had the 7-spd on four (count 'em four!) Mercedes so far and a couple of them had to be reflashed before they'd behave properly. One never quite got it right but even that one wasn't all that bad--just the clunky downshift approaching a stop. My point is that the 7-spd's woes may be exaggerated. Generally I think it's a great transmission.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top