Mercedes Benz M111: 200 230 Is Your Maf Sensor Failing? Why Does This Happen?

[@darrensharpe3345]

If you don't have the vacuum pipe running from the supercharger to the swarl pot it clogs up and starts drawing oil into the intake, that little bit of pipe is very important if you still run a standard air box and swarl pot.......... the constant stream of air from the supercharger to the swarl pot keeps the swarl pot clear and thus the intake and maf free of oil.👍

[@M-oneeleven-M111]

Exactly right it creates a draw through sort of system introducing a little extra pressure to assist the swirl pot as otherwise there is not enough pressure for the system to function as you say correctly 👍 great point to make aswell. Thank you 😃

[@geoffcampbell7846]

Really useful video mate, thanks. Thats super useful as I've just encountered the multiple mis-fire issue on my 230 SLK, so will be looking into that oil separator thingy. Keep em coming, much appreciated. 👍

[@M-oneeleven-M111]

No problem I'm glad you found it useful 😃, if not already please consider Subscribing. Multiple cylinder misfires are often caused by a sensor especially the MAF, occasionally on earlier Slks pre 2001 so pre Evo engine the coil packs break down too. So on the earlier engine if you have multiple cylinder misfires on cylinder 2 and 4 at the same time or Cylinders 1 and 3 at the same time there's a high likelihood it is the coil pack for those two cylinders breaking down. also another symptom to consider is do you long cranking so does it take a fair bit of cranking to start the car? This can be a sign of a failing crankshaft position sensor (fairly easy to change on a Slk thanks to the engine sitting further forward), or worst case can be a sign the headgasket is on its way out the original Victor reinze gaskets are known to fail on earlier engines. However if your engine is a post 2001 Evo engine this is highly unlikely. I'll link another video you may find useful: kzbin.info/www/bejne/bZXSoqybpLaonck

[@geoffcampbell7846]

@@M-oneeleven-M111 Cheers for the info. I've a 2004 slk, and linked to the other issues, its been pushing petrol out of the vent on the carbon emissions filter situated above the fuel pump/filter set-up. The car has gone in for its mot so I asked the garage to investigate. They think it may be a blocked filter, so thats been changed along with the carbon canister and it seems to have stopped the issue. We'll see if that does the job when I pick it up. I still want to change the MAF anyway as it's got its own issues me thinks, as per you video. Thanks again.

[@CarChris82]

great vid and info mate

[@M-oneeleven-M111]

Thank you mate appreciate it I tried not to make it too long and boring 😂

[@pedrodomingues9381]

Brake cleaner also does the trick. Being a SLK200, don't you have a re-learn throttle sequence? On an M111 you leave the car on ignition On without cranking the starter, around 3 minutes and the ECU will re-calibrate the TB.

[@redpig1120]

Great video..quick question..96 C230K….I put the larger crank pulley on..at full throttle it’s misfiring and now running rough..any thoughts..cheers..

[@w202cool9]

My w202 when go up to 10 km get rpm up and down, that sign maf have to be changed?

[@M-oneeleven-M111]

Hmm that's a good question that, could be MAF sensor but it could also Cam or Crank position sensor. If you unplug your MAF sensor see if it goes away, if the problem remains then the issue is not the MAF sensor 🙂

[@hussamal-momani4391]

Great video 👌. I'm having a failing maf sensor because of oil residue. The error codes (P0101 (MAF) & P200B ( i Don't know what that is) appears when scanned with obd2. I'm planning to give the intake system a good clean and install 2 oil catch cans as follows: 1- 1st one filters air coming from the valve cover before entering oil separator. 2- 2nd one one filters air coming through pcv valve. Would you please recommend such a process? And would this solve the problem of an oily maf sensor? My car is a 2001clk 230k

[@M-oneeleven-M111]

Thank you I'm pleased that it helps 😃 So the best way to go about it is like you say give the intake a good clean main thing (if your confident enough to work on your car and don't need to use it for a couple of days) is to get the intercooler off and soak clean that through with brake cleaner. Then leave it over night up on its end for it to drain and dry out. The next thing would be to run a hose from the valve cover/cam cover vent to a catch can the the outlet of the catch can could either have a filter or be Plummed back to the airbox like stock. As for the pcv there's no real need to do anything with that unless it has failed. We still run a PCV on our turbo Slk and just run a catch can for the cam cover vent. That should cure the oily MAF If not already please Subscribe 🙂

[@auto2419]

Hi, could you make a full video about the clk 192cv timing chain? thank you

[@M-oneeleven-M111]

I can do but I'm not sure how soon I can do it, but it is certainly on the to do list for the Clk as it's 6k off 100k miles now so it's definitely something we will cover 🙂.

[@zoli124mb]

I have poor idle and missfiring in my 97 CLK. The coils, spark plugs and the lamdba sensor are new. I guess, the MAF sensor is the problem. Which one is recommended? Bosch? Valeo?

[@M-oneeleven-M111]

Possibly MAF sensors but check the seal on your throttle body too buddy, the rubber o-ring that seals under the throttle body has a habit of becoming brittle and squashed over time and not fully sealing. Ide check for a vacuum leak first the best test for this is brake cleaner sprayed around the area of the intake manifold and throttle body, this has to be done with the everything standard in place and keep the brake cleaner away from the air intake itself. Also you need to use flammable brake cleaner sprayed as a mist, if the engine revs increase when you spray it around the throttle body or intake manifold you have a vacuum leak. (Disclaimer, if your are not confident using this method DO NOT attempt it as there is a risk of fire or engine damage is sprayed into the intake. This is at your own risk and I assume no responsibility for any damages or injuries using this method, it's a pretty fool proof method but I have to give a legal disclaimer on this kind of advice) Also you can just unplug the MAF sensor see if it runs any smoother (this will disengage the supercharger) but it gives you an idea if the MAF is actually the issue. Other sensors that can cause this are the cam position sensor and the crank position sensor, however a crank position sensor failure normally results in a non start issue. If it indeed the MAF sensor that is the issue always only buy Bosch the Bosch management system doesn't like non Bosch sensors for some reason, we've not had any luck using other brands and we have had enough of these engines and cars now to be able to say that confidently. Hope this helps you also here's another video that may help too. kzbin.info/www/bejne/bZXSoqybpLaonck 🙂👍

[@zoli124mb]

@@M-oneeleven-M111 i replaced the MAF sensor with a New Bosch sensor, the problem remained, poor idle, missfiring, and sometimes the supercharger doesn't work

[@JDMCARSCIVIC]

​@zoli124mb did you fix the problem? Gonna guess blocked exhaust?

[@zoli124mb]

@@JDMCARSCIVIC yeah. Engine swap. :😀

[@ismayilgof9573]

My car w202 c230k. Supercharger removed by previous owner and I want to assamble back. Is it possible? What should I pay attention to?

[@Ejfel_Garage]

Hey man! Like your videos! Do you know anything about supercharger stop working on normal temp? It works fine when its cold but not when the temp start to rise. Hope you got somthing for me!

[@M-oneeleven-M111]

Do the supercharger do this everytime the car is started? So just to clarify the car is started ran up to operating temp then the supercharger stops working as soon as it reaches operating temp? I am also assuming the engine is a pre- facelift M111 with the clutched supercharger pulley? So we need to work out if the clutch is slipping or if it is opening the bypass valve or it switching the charger of due to a fault. Now normally the only fault other than the bypass valve that's switches the supercharger off is a MAF sensor failure, it does this to protect the engine and the ECU switches the fuel map to a N/a map. Is the engine modified in anyway? As in modified I mean like an overdrive pulley.

[@Ejfel_Garage]

@@M-oneeleven-M111 sorry for the lack off information. You assuming all things right. I have no fault codes now and The engine and supercharger are original

[@gonzalogutierrez2690]

Hello, I have a slk 230k with double pulley kompressor ported intercooler kwe and relocation of maf that I install after adjusting the control unit. It fails me when I go to half a pedal or 3/4 of a pedal, it gives like a few small gas cuts and it continues to run the same ... but at full pedal, don't you give me any suggestions or help? my instagram is _230k_ a greeting

[@M-oneeleven-M111]

Hi there, the issue you are having is the MAF sensor topping out, this is cause by the double pulley causing the supercharger to generate more boost than the MAF sensor can read. ( When you accelerate does it feel like a harsh ignition cut the car basically bucks very violently?) This is a common issue even with single pulleys. Unfortunately most places sell these pulley's as bolt on modifications but don't explain that the MAF sensor doesn't like more than 0.7 bar of boost or seeing more boost sooner than it should. Also you need a higher Fuel pressure or larger injectors, we used a vw 4 bar fuel pressure regulator for below .7 bar and larger VW injectors for above .7 bar. We did use a BMW E39 M5 MAF sensor when we had crank pulleys on our cars. Im confident that you issue is due to over spinning the supercharger too much, what size pulleys are you using? But like I say the issue is linked to fuel supply or the MAF sensor seeing too much boost. I hope this helps you buddy 🙂👍

[@M-oneeleven-M111]

also is this car a pre 2001 car or post 2001 facelift, the earlier pre facelift Slk with the M111+M62 supercharger is on Bosch management which is what my reply refers to. the facelift Slk with the M111 Evo + M45 supercharger has Siemens engine management which behaves a little differently.

[@gonzalogutierrez2690]

I have speers pulley and the kompressor lowered I can not say how much since the mechanic did it. With a maf sensor of m5 e39 without adjusting the control unit would it work perfectly? how can it be that a maf bmw works in our 230?