Picking up on this old post. Our 2010 with 80,000 miles has had an intermittent problem with a check engine light. This was mentioned over the years when the GLK went in for service but dealership, who has always maintained the GLK, was unable to pull a code. The car was in for a new battery (June) & a code came up that had been stored, L105.20-P-051268, which is explained as cam adjustment solenoid bank 1. Prior to this, the CEL came on frequently, wife's car, so I do not drive it often but my driving style was different enough that it triggered the code. Since the reset of the CEL in June, the CEL has only shown once & after x number of start cycles, the warning went away & it has not reoccurred. There are no drivability problems such as rough idle. Yes, driving has been reduced due to the virus but in the past the CEL would kick on with a certain amount of regularity. Quote for this work is over $600.00 which imo is steep. The quote states "cam adjustment solenoid" but my research shows that the solenoid itself is not the problem but the magnets are. Pricing of the repair makes me think that the solenoids @ $65.00 each is what is to be replaced & perhaps the magnet but do not know for certain. Anyone out there have any thoughts about all of this? Unfortunately I do not know what the flat rate time is on any of these repairs. Look forward to any & all comments! TIA!

 

Sub'd....I'm going through this right now as well...taking my 2010 GLK 4MATIC into the dealer next Monday for the Takata Recall work and was already quote $572 for the B2 service (Oil Change, Brake Fluid flush, all others topped off, new cabin filter, multi-point inspection, suspension and tire checks)...ugh WTF, MBUSA needs to up their game on what I'm paying for after already giving them over $50k for this beast....but she's been good to us overall since we're currently at 193,000!

Okay, off my soapbox, keep us (me) informed of your progress good sir!

TIA.

-Travis

 

Back at this again with more research in the MB OEM parts catalog. First frustration is that one of the diagrams provided is shown in two different areas with different numbers & descriptions in each. The next issue is that the two parts I am trying grasp are in different diagrams & do not overlap. The camshaft control valve solenoid, 272-050-04-78, is in the engine section diagram. The magnetic sensor, 272-051-01-77, is also in the engine section but in a different diagram which happens to be the same diagram in controls but the parts therein are for the ignition. I know, the diagrams are only meant to be "representative". It is my understanding that the magnetic sensor works in conjunction with the camshaft solenoid but I cannot be certain of this. The dealership wants to replace the solenoids but from my research here & elsewhere, the solenoid is not the problem but the magnetic sensor is the culprit. Cost of replacing the solenoids is more than the sensors, the latter I could do myself if the Mrs. would allow me. So what I need to determine is whether the two part numbers I have given do indeed work in together or am I barking up the wrong tree? TIA!

 

Okay instead of doing what I should be doing more time spent researching. I think this link explains how the camshaft timing works better than anything I have found to date. Hope this helps.
https://www.eeuroparts.com/blog/merc...uster-magnets/ Evidently the part which the dealership intends to replace is # 2 in the first diagram but not the magnets.

 

OK, what is the next step? If you have the dealer replace part #2 in the diagram, you could also have them replace the magnets "while they are in there" and maybe save a few bucks on the labor cost.

 

The latest is a response from the service advisor who wrote the estimate. The reply states that the parts to be replaced are the magnet/sensors & not the solenoids. Confusion reportedly created by terminology although the estimate pictures a solenoid & not the magnet/sensor. I did another search on L105.20-P-051268 & found something interesting. https://www.tsbsearch.com/Mercedes-B...05-20-P-051268 This TSB says that the reason for replacing the camshaft solenoids is due to seizure or if not oil tight. From this I surmise that the camshaft solenoid is a mechanical device & the magnet/sensor which controls it is electrical. Furthermore the probable reason for replacement due to seizure is an oil contamination problem. The holes where oil flows through the solenoid are very small & dirt could block the orifices & cause the solenoid to seize. Our GLK has had nothing but MB oil & filter at less than the recommended 10,000 miles since acquiring at as a MB certified used vehicle when it was about a year old. In conclusion, the solenoids rarely fail & the magnet/sensors which have been superseded is the problem. Next is to ask the advisor whether the cost for the job is possibly incorrect. Three of the four magnet/sensors are easy to access requiring no tear down & only the one which is behind the p/s pump is more of a challenge. Overall, progress has been made!

 

I would avoid rationalizing yourself out of having a repair done and spending money. That is what I am reading in your post.

Seizure of a mechanical component can be from wear on either or both of the two moving parts. It can be from fatigue cracking, or from o-rings not functioning properly. Or from out of tolerance manufacturing on either or both parts. I think it's an inappropriate leap of faith to say because the vehicle has had regular oil changes with factory oil and filter that things are OK.

Post photos of your DIY if you decide to replace the parts, it helps current and future members of the site.

 

You are close @chassis but the work will be performed at the dealership this month. The issue comes down to what needs replacement & for what cost. Retired & fixed income with a car fetish is tough & where the dollars are spent is critical for me. This is the Mrs. transportation & whatever it needs it gets at the dealership. There is a lot out there, including photographs, on how easy the magnet/sensors are to replace. Only one is a toughie. The dealership will not review the labor cost but I now know which parts will be replaced. As a shade tree mechanic for over fifty years, the quality of the work I do is good. The other two vehicles in our garage I maintain.
As to the failure of parts. there is much out there about problems with engines as to variable timing components & cylinder deactivation which operates in ways similar to the variable timing. The purpose of both are the same, addressing concerns foremost for fuel economy & then emissions. What I read is that most problems go back to scheduled maintenance & the lack of periodic oil changes as these engines accrue miles. Travel back almost twenty years to the problems which Saab encountered with the 2.3 turbo engines. Long service intervals & non synthetic oil recommendation along with PCV issues (piston ring design) caused many engine failures. Full synthetic oils, shorter service intervals & several redesigns of the PCV emission system resolved the problem such that 2003 & newer had few engine failures. Today in current light-turbo applications, at least one of the big three auto manufacturers are only requiring semi-synthetic oils. How long will it be before problems crop up? Not for the first owner but the next owner possibly will have to deal with the results. Now I need to go & pull up the cushions in the couches to see if I can find enough money for the work needed on our Z3 Roadster.