C250 2011 EGR problems

[phillwoodsy]

hi there was after some advice I haven't had the car long and it is playing up with the EGR valve, keeps going into a kind of limp mode with the engine management light coming on, the garage has tried a forced regeneration but this only solves the problem for a week or so , any advice would be much appreciated

 

[Craiglxviii]

hi there was after some advice I haven't had the car long and it is playing up with the EGR valve, keeps going into a kind of limp mode with the engine management light coming on, the garage has tried a forced regeneration but this only solves the problem for a week or so , any advice would be much appreciated

Have it pulled out and cleaned. Had this done on the X Trail a few weeks ago, transformed the driving and fuel consumption went from 29 --> 36mpg overnight.

 

[patxi]

Are you confusing your exhaust system components?

The EGR valve will cause limp mode and warning light if it fails to operate, but 'forcing a regen' is normally associated with a clogged up DPF.

Has the garage told you the DTC error codes for the fault?

 

[phillwoodsy]

Ah right I believe I may be confusing the two . I thought they were related . They did a force regeneration on the car about 10 days ago but it has gone back into what I would class as limp mode and the engine management light is on .. taking it back in tomorrow .. just hoping to get to the bottom of it and seeing if anyone knew anything more about it

 

[phillwoodsy]

My bad yeah looks like I got mixed up .. they did a force regeneration in it about 2 weeks ago and now I'm back to square one.. thought the 2 were linked .. just after ideas of anyone has had the same problem solved

 

[patxi]

Please be clear, unless you can tell us the fault codes that are associated with the EML the only answers you get will be guesses.
Here are my thoughts.
I think it is relevant that you got a regen done and this kept the problem away for 2 weeks. If the EGR valve was the problem I would expect it to register a fault shortly after you started driving again.
In the 2 weeks did you drive 6~800 miles before the light came back on? That would be a typical regen distance, so it sounds like the car has not (or could not) instigate a regen of the DPF before the soot levels accumulated to the point of causing the warning light. If this is the problem then the most likely suspect would be the DPF pressure sensor. You can read all about this part on this link
The ones on sale in the link are pattern parts (not OE). If after more research you decide to buy one check the MB price, they are not much more (say £40) but will be the exact one for your vehicle. To get a price from the dealer you will need to give the chassis number.
Hope that helps

 

[phillwoodsy]

Thanks for that advice it certainly sounds like what u said as I did about 7-800 miles beforeast it played up again . I haven't long had it so it's back in the garage to get sorted .. I just like to hear from people's experience, as you well know the garages sometimes fob you off . Hopefully a pressure sensor is the outcome and then it is solved . Just hope it's not going to be a reccuring problem

 

[HITECH]

Thanks for that advice it certainly sounds like what u said as I did about 7-800 miles beforeast it played up again . I haven't long had it so it's back in the garage to get sorted .. I just like to hear from people's experience, as you well know the garages sometimes fob you off . Hopefully a pressure sensor is the outcome and then it is solved . Just hope it's not going to be a reccuring problem

Just interested what error codes you had for this and did you get it sorted. I have worked on and fixed quite a few with a 1402 error causing limp mode no matter what u do to the egr or do a forced regen etc etc etc. It will intermittently throw up other faults pointing to the EGR. The simple fix for a 1402 ( if u had it ) is replace the DPF sensor. And ensure u replace it with a decent one because cheap equivilents from china etc etc dont communicate with the ECU very well and limp mode still exists. Just giving you this info from my own experience. Fault sounds similar.

 

[bembo449]

get it remapped and disable the EGR function , cheaper and less hassle than any other option imo

 

[Jerry1975]

Hi there,

I'm no expert but in m experience you need to establish whether your problem is with the EGR valve or with the Diesel Particulate Filter (DPF) in the exhaust. They are both emissions related but are very different.

What is the mileage of the car?

Do you have much idea of the kind of use the car had with the previous owner (i.e. did they do a lot of town driving and not much motorway?)

In my experience I've seen many cars have iffy EGR valves that can fail after 60k miles or so (my brother had a Jag X-Type 2.2 and it went through 3 EGRs by the time it hit 100k miles!) Usually the seals tend to go on them and they leak oil vapour everywhere and make a mess of the engine bay. The resultant gunk tends to make them stick and not operate properly, thus causing the engine to go into limp mode. The only fix is either replacing the EGR or stripping it down, cleaning it up and replacing the seals, though this can be more expensive than replacing the EGR unless you do it yourself.

The other method is to bypass the EGR with a blanking plate of some sort and then getting a remap done to disable the EGR sensor and stop it limping. These days though a lot of garages won't do this because it is now an MOT fail if the EGR or DPF have been bypassed or removed. This is a bit annoying though because the bypass is by far and away the best way of avoiding further problems (I have an Audi A4 that has done 120k+ miles since I bypassed the EGR without any issues).

From what you describe though, I'd put money on the car having a partially-clogged DPF. The regens the car does are not clearing the DPF fully and therefore the internal capacity of the DPF is vastly reduced, which will cause it to fill the remaining space quicker and bring on a limp mode/regen sooner.

I'm not sure how helpful Mercedes would be at properly solving this without trying to fleece you for a brand new DPF at great cost, so personally I'd look around for an independent garage (possibly on here) that could clear it out for you. This would give you the best results.

Unfortunately, due to the law change on removing/bypassing DPFs the regular regens are something you will have to get used to. Hopefully though with a nice, clean DPF these will happen a lot less.

Hope this helps

J