Stuttering Performance W212 E350 CDi

[DavieB_Glasgow]

Good afternoon folks,

Firstly, I'm new to the forum so apologies if this post is in the wrong location or has been covered previously, still finding my way around. Having read through the forum there's an amazing wealth of knowledge so I thought I'd share my woes to stimulate the grey matter of those that are mechanically minded as I am not.

I have a 2010 W212 E350 Blue Efficiency CDi AMG sport which I believe to be the full title of the model? The car has 88k on the clock with a full and comprehensive service history from a combination of Main Dealer until 2017 when I started using a recommended independent in Govan, Glasgow.

The car has recently suffered from faltering performance, by this I mean the acceleration has been severely restricted. This resulted in the engine management light coming on. A trip to the specialist resulted in a new EGR valve being fitted 2 weeks ago. Since then the performance improved greatly but has been a tad lacklustre which has come to a head with me being back in a similar position. Whilst on the motorway yesterday the car wouldn't go above 3,000RPM and gear changes were rough as it went through lower gears - faltering DPF regeneration has been suggested for this aspect?

Yesterday the cars performance was severely restricted again but it utilised the full rev range and gear changes were fine. This performance issue triggered the engine management light again. The car is off the road until Thurs when it goes back in for assessment. For this aspect a mass airflow issue has been suggested?

I guess my question would be - has anyone else suffered similar or be able to offer insight into this one based on my probably vague description? Either way I'll update the thread off the back of the diagnostic in the hope it helps someone else. Although I trust the garage it's always good to have a rough idea!

 

[John Laidlaw]

MAF quite possible but a diagnostic is essential

 

[CowleyStJames]

No good throwing parts at it.
Read the fault codes and take it from there.

 

[Westheath]

Diagnostics first as always.

But the Maf's are common failure on those,
used to be sold separately but now the whole units replaced as one.

 

[DavieB_Glasgow]

Agreed, don’t want to throw parts at it but the previous diagnostic pointed to the EGR valve hence the replacement. Obviously more to it than the EGR diagnosis though if it’s still running rough.

It’s unfortunate the the MAF is now one unit should the diagnostic point to it but the car has been bomb proof with routine maintenance so the odd replacement part is fine and commensurate with age/mileage.

Thanks for taking the time to respond, I will update on Thurs after visiting the garage.

 

[Westheath]

EGR and MAF work together and depending on what was used for diagnostics last time
unless it was a decent machine, MB Star, Launch or Snap On, interpretation can be flaky,
the operator needs to read the values shown and not just jump on a fault code produced
by the code reader/diagnosis equipment.
Unfortunately a sticking EGR and failing MAF are common issues,
clean up the EGR is usually ok but MAF's usually return the fault after cleaning.
The double whammy.

 

[DavieB_Glasgow]

EGR and MAF work together and depending on what was used for diagnostics last time
unless it was a decent machine, MB Star, Launch or Snap On, interpretation can be flaky,
the operator needs to read the values shown and not just jump on a fault code produced
by the code reader/diagnosis equipment.
Unfortunately a sticking EGR and failing MAF are common issues,
clean up the EGR is usually ok but MAF's usually return the fault after cleaning.
The double whammy.

Thanks Westheath, yeah it looks like the double whammy indeed! I believe they use MB Star as I enquired about their diagnostics/software before using them due to the electronic complexity of these cars. Like most folk I used to do very basic servicing with my first cars myself because I was skint and a J reg Fiesta was about as mechanically complex as my childhood hand-me-down Raleigh Grifter. The most I do these days is replace the magic tree and give it a wash and polish!

After 88k of service on the original EGR and potentially the MAF (sounds like the cause of the issue) I'm going on the basis that these replacement parts will more or less last the rest of the cars useful lifespan as I intend to run it until it reaches a point whereby it's uneconomical to repair. Hopefully that's some way off yet

 

[DavieB_Glasgow]

Just to update the thread with the outcome of the visit to the garage. After a fault code reading and diagnostic to check the cars various values a defective DPF pressure sensor has been diagnosed. Including the diagnostic, labour and a genuine replacement part it's a total of £130. Hopefully this will resolve the issue!

 

[John Laidlaw]

Thanks for the update- very reasonable. Yes, hopefully that will resolve it

 

[malcolm E53 AMG]

Thanks for the update, always useful to know what problems these cars can throw up and the remedy, hope it continues to give good service. Sounds like MAF, EGR and DPF sensor problems are fairly common approaching 100k miles