MAF assembly - how to undo the flexy connectors

[MarkE350]

Hi there,
New to this forum and could do with some help please.
My 2014 C207 E350 Coupe has thrown an engine light and then using OBD2 reader a P0102 Mass Air Flow error. Tried a reset but it came back so I decided to have a go and remove and clean the MAF sensors.
I have managed to get the whole assembly removed from the 2 airboxes and turbo, but for the life of me can't figure out how to remove the MAF sensor housing from the rubber flexy connections to the centre housing. I am worried if I force them I will break the plastic housing. Searched forums and youtubes but couldn't find anything, advice would be much appreciated...

 

[Dodipops]

You can’t, they are all bonded on, you have to buy that whole section in the picture to replace just one sensor.

You could hot scalpel the sensors out then plastic weld them back in, if you were confident enough, otherwise just have to spray isopropyl spray in and then some compressed air??

 

[MarkE350]

You can’t, they are all bonded on, you have to buy that whole section in the picture to replace just one sensor.

You could hot scalpel the sensors out then plastic weld them back in, if you were confident enough, otherwise just have to spray isopropyl spray in and then some compressed air??

Hmm thanks, very frustrating as there appears to be a Bosch OE MAF sensor that isn't a crazy price (even for the 2 I would need) but it is one digit off on the part number BOS0281006487 versus BOS0281006488 that are on the car - maybe the 1 digit difference stands for "we made it impossible to change by gluing it all together..." The web site says it is the equivalent though hmm... Anyway I have tried cleaning the existing sensors and fingers crossed a miracle will happen and when I put it all back together again the fault codes will stop pestering me..

 

[OneForTheRoad]

I doubt you'd of cleaned the sensors , even with a spray , they face the opposite way to the opening and the hot film is covered in it's own little housing.

You can split that joint with hot water and a heat gun if you're careful.

 

[ALFAitalia]

I replaced MAF sensors from "sealed housing" on many cars. The Bosch number stamped on them is for the sensor alone. Easily available from Bosch for a fraction of the cost of the main dealers. You often find out that they are used in many other cars in the process. Why replace all the perfectly good rubber? On my last 159 I managed to break it free with constant wiggling....and a smear of Sikoflex sealed the new one back in.

 

[OneForTheRoad]

You could try one of these , but mmmmm I'm not convinced tbh.

 

[MarkE350]

As predicted, cleaning (or attempting to) made zero difference. I think my next plan is to buy a repro entire unit and see how that goes...

 

[Gnasher141]

As predicted, cleaning (or attempting to) made zero difference. I think my next plan is to buy a repro entire unit and see how that goes...

Good luck with that. I did the same thing and it didn’t recognise the sensor, so had to return. I ended up getting a guaranteed second hand assembly complete.

 

[MarkE350]

Thanks for the replies, a bit of positive progress. Using a heat gun (on low setting) the plastic collar does become pliable and with a bit of care and patience I have managed to separate the sensor from the assembly. I also noted that the Bosch replacements seem to come without the clip/spring for attaching to the airbox - again with a bit of heat to try and prevent the plastic breaking I have managed to remove them. I think I am just about confident enough now to risk buying the 2 Bosch sensors....

 

[OneForTheRoad]

Thanks for the replies, a bit of positive progress. Using a heat gun (on low setting) the plastic collar does become pliable and with a bit of care and patience I have managed to separate the sensor from the assembly. I also noted that the Bosch replacements seem to come without the clip/spring for attaching to the airbox - again with a bit of heat to try and prevent the plastic breaking I have managed to remove them. I think I am just about confident enough now to risk buying the 2 Bosch sensors....

Lettuce know how that goes , could save alot of us a few hundred quid

 

[MarkE350]

My first attempt at getting the rubber flexy and collar back on the MAFs resulting in failure - the rubber flexy got slightly distorted, see 1st photo.
So back to the hot air gun (on low setting) and another try. This time I made sure when I pushed the MAF sensor onto the hot plastic collar I kept everything as square as possible when I pushed it back on. A bit of satisfying "clicking" later and now both MAF sensors seem to be securely back onto the flexys. I am just waiting for the orange seal that goes into the plastic centre piece to arrive at the local MB dealer (anyone know what this is, my guess is it is a crankcase breather pipe??), then crossed fingers I can put it all back on the car. I have new airbox seals and turbo seals to put on too. But air filters have only done 2000 miles, and look perfect, so not changing these.

 

[OneForTheRoad]

My first attempt at getting the rubber flexy and collar back on the MAFs resulting in failure - the rubber flexy got slightly distorted, see 1st photo. View attachment 162181
So back to the hot air gun (on low setting) and another try. This time I made sure when I pushed the MAF sensor onto the hot plastic collar I kept everything as square as possible when I pushed it back on. A bit of satisfying "clicking" later and now both MAF sensors seem to be securely back onto the flexys. I am just waiting for the orange seal that goes into the plastic centre piece to arrive at the local MB dealer (anyone know what this is, my guess is it is a crankcase breather pipe??), then crossed fingers I can put it all back on the car. I have new airbox seals and turbo seals to put on too. But air filters have only done 2000 miles, and look perfect, so not changing these.

View attachment 162180

Good job so far . Hopefully no errors once the engines running. Yes the pipe is part of the pcv system. Air filters will be good for 40k .

 

[MarkE350]

And it would appear I have actually succeeded, the car is running fine, no check engine light after 4 restarts including a decent 45 mins drive with some motorway - before when I reset the light it was coming on every time after 2 restarts.
I read somewhere that if you leave the 2 MAF cables disconnected initially and idle the car for 30 seconds, then reconnect the cables it gets the ECU to re-learn new sensors, so I did this after putting it all back together - anyone know if this is fact or fiction?
One final question, anyone got recommendations for a decent OBDII scanner that will also do the resets (e.g. DPF regen, service light etc), mine is a very very basic one and I fancy an upgrade?

 

[OneForTheRoad]

And it would appear I have actually succeeded, the car is running fine, no check engine light after 4 restarts including a decent 45 mins drive with some motorway - before when I reset the light it was coming on every time after 2 restarts.
I read somewhere that if you leave the 2 MAF cables disconnected initially and idle the car for 30 seconds, then reconnect the cables it gets the ECU to re-learn new sensors, so I did this after putting it all back together - anyone know if this is fact or fiction?
One final question, anyone got recommendations for a decent OBDII scanner that will also do the resets (e.g. DPF regen, service light etc), mine is a very very basic one and I fancy an upgrade?

Most icarsoft scanners are decent , I found the mb3 would read everything on my 2017 e350 , won't read bugger all on my 19 reg GLC , good old mb changed protocols . Don't be fooled by the dpf regen chatter you read about , it just doesn't work , at least not a static regen . Congratulations on the mafs though. You've started a trend . Put a link on please to the Bosch units you bought .

 

[W1ghty]

And it would appear I have actually succeeded, the car is running fine, no check engine light after 4 restarts including a decent 45 mins drive with some motorway - before when I reset the light it was coming on every time after 2 restarts.
I read somewhere that if you leave the 2 MAF cables disconnected initially and idle the car for 30 seconds, then reconnect the cables it gets the ECU to re-learn new sensors, so I did this after putting it all back together - anyone know if this is fact or fiction?
One final question, anyone got recommendations for a decent OBDII scanner that will also do the resets (e.g. DPF regen, service light etc), mine is a very very basic one and I fancy an upgrade?

Very very clever buddy ! Excellent job .

 

[MarkE350]

Most icarsoft scanners are decent , I found the mb3 would read everything on my 2017 e350 , won't read bugger all on my 19 reg GLC , good old mb changed protocols . Don't be fooled by the dpf regen chatter you read about , it just doesn't work , at least not a static regen . Congratulations on the mafs though. You've started a trend . Put a link on please to the Bosch units you bought .

These are the Bosch MAFs I bought from Autodoc: https://www.autodoc.co.uk/bosch/14762010

 

[MLHappy]

These are the Bosch MAFs I bought from Autodoc: https://www.autodoc.co.uk/bosch/14762010

Hi Mark do you fancy doing my MAF replacement?! Well done on a great job

 

[kingkhan]

Thanks for the replies, a bit of positive progress. Using a heat gun (on low setting) the plastic collar does become pliable and with a bit of care and patience I have managed to separate the sensor from the assembly. I also noted that the Bosch replacements seem to come without the clip/spring for attaching to the airbox - again with a bit of heat to try and prevent the plastic breaking I have managed to remove them. I think I am just about confident enough now to risk buying the 2 Bosch sensors....

Exactly the picture o was looking for! Thanks mate. You're a legend because you've done a great job.

I'm stuck.My question is how do i remove the plastic swing clip from my old maf sensor?

Thanks mate

 

[ALFAitalia]

I must admit I thought you would just be buying the sensor itself....just the bit the plug goes onto (similar to google generic pic below).....that's what I have used in the past....they are cheaper like that as they are used on lots of different cars whereas that plastic moulding will only be use on a few. Good job either way.

 

[OneForTheRoad]

I must admit I thought you would just be buying the sensor itself....just the bit the plug goes onto (similar to google generic pic below).....that's what I have used in the past....they are cheaper like that as they are used on lots of different cars whereas that plastic moulding will only be use on a few. Good job either way.

View attachment 163923

Probably because they are heavily bonded .