W212 subframe preemptive check

[cheapshots]

Hi all,

I came across the subframe issue and went down a rabbit hole !

I wonder why some cars seem to be affected but others not, were the subframes made in different factories to different standards and it's a case of your bad / good luck?!

I've got a W212 facelift, 2013, 100k mileage, parked outside all the time - no MOT advisories.

Do you think it's worthwhile getting Merc to do one of those visual health checks ? Looks like the corrosion starts from the inside anyway so I'm half thinking what's the point of a visual health check

 

[W1ghty]

Hi all,

I came across the subframe issue and went down a rabbit hole !

I wonder why some cars seem to be affected but others not, were the subframes made in different factories to different standards and it's a case of your bad / good luck?!

I've got a W212 facelift, 2013, 100k mileage, parked outside all the time - no MOT advisories.

Do you think it's worthwhile getting Merc to do one of those visual health checks ? Looks like the corrosion starts from the inside anyway so I'm half thinking what's the point of a visual health check

I suppose if MB were to check it and whack it with a hammer as part of the test , you could do with knowing if they would replace it FOC if it failed .
If it fails there , you would have to recover it on a low loader if you wanted someone else to do the replacement.

 

[markjay]

My understanding is that the inside of the rear subframe can be checked using a bore (inspection) camera. But I doubt that an MB dealer will do this for you FOC.

 

[cheapshots]

I booked a health check for £30 - MB Hemel Hempstead. It's in 2-weeks.
These cars, always something to worry about!

 

[jon89]

I have a om651 engine c250d. Does branded oil really make a difference?

 

[markjay]

I have a om651 engine c250d. Does branded oil really make a difference?

No. But the spec does. Make sure it says MB229.52 on the box.

 

[ALFAitalia]

I've got a W212 facelift, 2013, 100k mileage, parked outside all the time - no MOT advisories.

That's quite often the case....just before a hole appears or something snaps!!....they rot from the inside....the MOT is only a visual check from the outside....so I hate to say it a fresh MOT proves nothing! Im going to paint mine (212 2010) and rust proof it as much as I can , inside and out. I do have a cheap borescope which plugs into my phone that I'll use to look inside before I spray the rust killer inside....just make sure that's its good and solid. It certainly looks fine from the outside and its been a Kent/Sussex car its whole life and we don't see much winter salt in these 'ere parts!!!.......so I'm hopeful she will be solid. I wont be doing it for a couple of weeks....so will report my findings and hopefully be able to post my images of the inside of the frame....image quality dependant.

 

[Londonscottish]

That's quite often the case....just before a hole appears or something snaps!!....they rot from the inside....the MOT is only a visual check from the outside....so I hate to say it a fresh MOT proves nothing! Im going to paint mine (212 2010) and rust proof it as much as I can , inside and out. I do have a cheap borescope which plugs into my phone that I'll use to look inside before I spray the rust killer inside....just make sure that's its good and solid. It certainly looks fine from the outside and its been a Kent/Sussex car its whole life and we don't see much winter salt in these 'ere parts!!!.......so I'm hopeful she will be solid. I wont be doing it for a couple of weeks....so will report my findings and hopefully be able to post my images of the inside of the frame....image quality dependant.

Let me know how you get on - especially in terms of the camera. I fancy getting the inside of mine sprayed with Lanoguard or whatever but I'd like to know what it's like inside first.

 

[Skd884]

I booked a health check for £30 - MB Hemel Hempstead. It's in 2-weeks.
These cars, always something to worry about!

Book a value service for £139 it includes a health check -

Post in thread 'Superb service from MB Guildford'

May 1, 2025

£139 main dealer service booked for the year end.





Oil snake no thanks -

• Skd884

• 

 

[DSM10000]

I have a om651 engine c250d. Does branded oil really make a difference?

Not the best idea to jump on a thread with a totally separate topic.

 

[cheapshots]

Thanks for the replies.

Because, as others have kindly mentioned, it rots from the inside I don't think there's much point doing the MB health check, they certainly won't check for rot from the inside.

I found a local garage who agreed to check the subframe, I will try to get get a close look myself and push them to do a thorough check! Planning to do this next week.

 

[W1ghty]

Let me know how you get on - especially in terms of the camera. I fancy getting the inside of mine sprayed with Lanoguard or whatever but I'd like to know what it's like inside first.

Dinitrol , I use on mine , buy the extended flexible 1m nozzle to make it easier .

 

[MarkNovack]

Its easy to probe with a pick. But frankly, I would wait until you get orange (I don't know your MOT categories) flagged on inspection. That will put a fire under your dealer's feet to get it fixed and your next frame will last that much longer. Then lift the car with the new one and give a generous coating of WD-40 annually. Some people tack weld water spray shielding in front of the worst of the offending openings. A shop sharpie could probably use heat and a plastic food cover to make a press on lid. You shouldn't close it, but it doesn't need to be open to all the mud and filth that can be forced in. The filth holds in the humidity and that's the major problem.

 

[MarkNovack]

I have a om651 engine c250d. Does branded oil really make a difference?

No. Just correct specs. Mine demands low ash for the DPF.