W208 230k Supercharger Issue

[John Jones Jr]

Well not found one anyway and mines a 99.

Deffo, your engine has a Cam sensor. Have a look at this vid, it's a non Kompressor M111 engine but basically the same.

https://www.youtube.com/watch?v=mmiZ6q3Ztm8

 

[streethawk]

Deffo, your engine has a Cam sensor. Have a look at this vid, it's a non Kompressor M111 engine but basically the same.

https://www.youtube.com/watch?v=mmiZ6q3Ztm8

Aha I see can't believe never noticed it. Wonder why they change position on later model.

 

[adambear]

Isnt this my camshaft sensor? This is what I unplugged and this stopped the rattly sound from the camshaft

 

[adambear]

This isnt my engine buy the way, its just a photo from google but the sensor on the front looks the same

 

[flango]

When my cam sensor went it showed up as an intermittent supercharger fault one minute it would cut in the next it wouldn't

I put it in Star and it came up with the codes for the air bypass valve, swapped the valve for a known good one courtesy if a member on here and same fault

Put the car on Snap On Pro diagnostics went out on a run with the diagnostics connected to record data and the cam sensor magnet showed up straight away contaminated by oil. The new cam sensor has modified wiring to stop the oil tracking up the wiring

Hope it's something simple for you

Sent from my iPhone using MBClub UK

 

[flango]

Isnt this my camshaft sensor? This is what I unplugged and this stopped the rattly sound from the camshaft

That's the one

Sent from my iPhone using MBClub UK

 

[John Jones Jr]

Isnt this my camshaft sensor? This is what I unplugged and this stopped the rattly sound from the camshaft

No, that's the Cam solenoid (it adjusts the inlet cam giving variable cam timing). The Cam sensor is to the right front of the head when looking at that photo. See vid clip I posted previously.

 

[flango]

Sorry I should have been more clear in my post it was not my cam position sensor as in the video it was the cam sensor solenoid on the front if the engine the one you identify with the red arrow that was my problem some people refer to them as cam sensor but John Jones Jr is correct with his terminology never had a problem with my CPS though

Sent from my iPhone using MBClub UK

 

[John Jones Jr]

never had a problem with my CPS though

But they are a known problem.

 

[flango]

But they are a known problem.

They are indeed a very common problem on that engine

Sent from my iPhone using MBClub UK

 

[adambear]

I disconnected the cam sensor in the side of the engine and engine barely run, so can I assume this sensor is working ok?

 

[John Jones Jr]

Sounds like a fair assumption to me. I say that as I never bothered to try it. What I did when I got my C230K was buy a MAF (one fitted was a non branded part), Cam Solenoid (looked original), Cam Sensor (leaking oil) & Crankshaft Sensor (known to go suddenly & looked original) and fitted the whole lot. But, I'd no issues with the S/c failing to engage, it was just good preventive maintenance for my point of view.

 

[John Jones Jr]

The more I think about your problem the more I'm swayed towards an ECU fault. If you look at S/c engagement faults reported especially on the U.S. forums, most seem to be intermittent faults of the clutch operation, cured by replacing/repairing the K40/4, MAF, etc. Any that have total non engagement of the S/c and I think I've only read about two cases these were resolved by replacing a blown Mosfet in the ECU. That's besides the oil wick fault from the loom at the Cam Solenoid to the ECU (thus ECU contamination).

I don't want to be an alarmist in mentioning the ECU even if it's a straight forward fix providing your reasonably good at soldering, but it's worthwhile doing a bit of reading on that R170 forum I posted earlier, to make a reasonable & educated guess of what course of action you should take next, bar of course getting any codes read on Star or the equivalent.

 

[adambear]

The soldering doesnt phase me really, I do agree it feels a bit like above and would be great if its easy as that. My worry would be getting the correct chip to replace like for like. Its a shame the ecu's cant just be changed like for like. Do you think if it was the ecu that failed this would be obvious plugging into a reader? And can I just say a massive thanks to every one for your input, im very grateful and your a credit to this site

 

[John Jones Jr]

No issues about getting the correct Mosfet, just look on the R170 forum, all the specifics are there, even where to purchase from. You can change the ECU's but you must get the replacement ECU 'unlocked' (from what I've been reliably informed), there is a couple of U.K. companies that offer that service. But, hell another ECU could have the same problem, different problems or have it's Mosfet on it's way out.

I've no idea what Star would show up if there's an ECU fault, I'd imagine several codes?

Anyway, let us know how you get on in due course. Good luck.

 

[adambear]

Thank you, I pulled out the ecu, took it apart and had a look at the mosfets in question. I pulled off the heak sinks and they didnt look damaged or burned (not even sure if they would if the were faulty) and then put everything back together. It defo looks like its a sensor/ecu fault as after the car was started the supercharger came on an worked perfect. But after a few revs of the engine it stopped working again. I repeted disconecting the ecu then plugging it all again sure enough the s/c worked for a few revs. I then done the above again and checked the air bypass valve with the main pipe off. The s/c worked for a few revs and the bypass valve was correctly opening and closing to match the revs and the boost produced was very strong. I'll have a propper look into this mosfet replacement now?

 

[John Jones Jr]

Change the Mosfet anyway would be my advise, as it will cost nothing bar a little bit of time and will eliminate a known culprit. Then just come back here and tell us all is o.k.


Edit: There is only one known (one out of three on one side of the board) problematic Mosfet from what I gather and I suspect just by looking at it won't indicate that it's faulty.

 

[John Jones Jr]

Here's a photo. All thanks to A1EK, who I'm fairly sure is a member here too.

Edit: Worth reading if you haven't already.

http://www.benzworld.org/forums/r170-slk-class/1684378-supercharger-fault-help-please-8.html

 

[adambear]

Yeah looks like a very detailed thread, I've found a replacement on ebay for £4.20, I am going to read this a few times lol to make sure I take it all in

 

[adambear]

No news yet, the part has now arrived but not the drivers side wheel bearing blew up and has fused to the stub axel. I cant drive the car now so am after a new stub axel now, hopefuly be able to update you all soon.