I hope you answer, I need to know, my slk230 supercharger is always on, the magnetic field rotates even at idle, I did not see the bypass valve closing when I gave gas, I do not know if the problem is the supercharger or the valve, it just gives P0806 clutch position sensor fault.
Hi, the bypass valve will not close if the ECU sees any problem with the supercharger or air intake system, the clutch staying engaged is a unique problem to have as normally the clutch fails causing the supercharger to not engage. So there's a few possibilities of problems. Has the supercharger been like this since you bought the car or is it a new issue? The reason I ask this is it is not uncommon for people to lock the clutch pulley. If this is a new problem it's possible that the ECU is actually at fault but this is rare. Is it possible the wires for the supercharger are damaged or it could simply be that the clutch pulley has failed and somehow managed to lock itself. The outer part of the pulley will rotate at idle however and the inner should only engage after around 1800-2500 rpm when the engine is unloaded (static revving) there is a video on the channel and many more on UA-cam showing the standard engagement of the supercharger just to be sure that is indeed always on. But if it is giving you a fault code for it that's a pretty good indicator, it is very rare for one of these pulleys to have such an issue unless someone has previously locked the pulley using the washer method inside the standard pulley.
I have problem with bypass valve,magnet on my sc clutch burnt and i make it clutchless and unplug the clutch wiring and now the bypqss valve doesnt work its just stuck open
This is because the ECU is in its "safe mode" when it reads boost at incorrect point so if it sees boost at idle that's a overboost situation, so to protect the engine the ECU opens the bypass valve to vent as much boost as possible as it can't control the boost. The only way around this is to make a 50mm butterfly style vacuum operated valve. You need a eBay or Amazon vacuum exhaust valve a manual boost controller some t pieces and vacuum lines. There are some videos on the channel of this, but it takes time to manually adjust the boost controller to slow down the valve closing so the car works normally otherwise it can run rough. The only other issue with this is the car then runs on a naturally aspirated fuel map rather than the adaptive map under normal operation. The only right way to fix this is a new clutch pulley unfortunately but you can mask the issue with a vacuum valve, a normal BOV style valve will not work in my experience. I hope this helps
@@M-oneeleven-M111 i have installed a clutchless SC pulley but i removed the electronic part of the clutch and fixed it on the engine bay, still connected to the BPV. The power has gonne up and the ECU sees no problem with it, as it is still sending the signal to the "clutch" and opening/closing the BPV when needed Power has gonne up and so i thought the boost would have gonne up aswell, but when i installed a boost gauge, it now reads 0.5bar which, from what i've heard, is stock... I've dynoed the car and im now making 212hp and 335Nm of torque How is this possible if i'm making the same boost as stock? I have a clk 230k m111.975
I forgot to mention that the reason it's making more power is because im using a smaller SC pulley, so it should make more boost as far as i know because it is rotating at higher rpms, but maybe im missing something?
I think I might have problems with mine, Is this a "safe" way to test it. removing the tube, starting it and revving it? (I have a SLK200 1998 R170 M111.943)
I'm very sorry for such a late response you may have already tested it by now unfortunately I don't always get notified of comments. Without DAS/SDS this is the only way to really test the bypass valve unfortunately. You can check with it removed from the airbox by just turning the ignition on the valve will actuate. But to test properly this is the only real method. This is a safe way to test aslong as you make sure there is nothing loose that can fall or be drawn into it, this is because the engine draws through here prior to the Supercharger engagement. Once again I sincerely apologize for the mega late responce
Hello and thanks for these videos my current code is a P1235 researching and cant seem to figure this out The compressor is not pulling in and the air flap is not operating I installed a used flap it also is not working. I recently got the car after sitting for 4 years with a head gasket failure, its all sorted now replaced fuel filter plugs, coil packs ,wires and injectors. fuel pressure is ~55PSI The Vanos plungers was a bit sticky when putting it back figured it didn't have any oil not sure if it's related. Any thoughts on a fix or test I have a Launch .X431 tool 1999 SLK 230 US version
Thank you I hope they help, for anything where the supercharger does NOT engage this is usually a sensor related to fuel mixture so MAF sensor, O2 sensor or its the bypass valve. The most common thing on these cars is the MAF sensor failure due to oil contamination and this causes the same issues. In these cases the MAF sensor should always be replaced with a genuine Bosch sensor, however you can sometimes clean them I have a how to on the channel. Sometimes cleaning them can be enough to get them working again. Second to that is O2 sensor failure but less common but as the headgasket has failed before it may have damaged the O2 sensor. Thirdly is the flap which you have replaced, Fourth is the clutch pulleys can sometimes fail, but not that often and in super rare cases the MOSFET transistors in the ECU that control it can fail but this is very rare! I hope this gives you some idea where to go from now, thanks for watching 👍
There's two ways you can make a blocking plate there is a video on the channel it's not the recommend way of doing it due to unfiltered air being able to enter the system, but I shall give you the link to that: ua-cam.com/video/xmEu6i-Nb7k/v-deo.html .... Then there's the Better way that if you have the tools already doesn't cost a thing it requires two airbox mods that will also improve top end performance :ua-cam.com/video/oqMHZ-T-kEg/v-deo.html firstly do that mod it takes out the restriction on the intake secondly do this mod: ua-cam.com/video/An0uOoezuUg/v-deo.html then for even more noise you could use a Pipercross foam panel filter. If you go with the airbox option be sure to make the holes where I did on the wing/fender side of the airbox as it's the coolest area of the engine bay, obviously drawing in warm engine bay air is not ideal but to be honest I never had any negative effects. The stock intercooler is the biggest problem for high intake temps anyway. Also taking the air guide out for the diverter valve does cause turbulence in the airbox but again you did not notice it. Also if not already please subscribe 👍
Hi is there any way to remove or bypass the bypass valve, iv got a new genuine Bosch maf sensor and iv tried 2 different bypass valves both do a self test with ignition on, neither close on full revs whilst stationary, iv heard some mercs suffer from problem in the ECU causing bypass valve not to operate, any and all advice will greatly be appreciated, iv owned my pre facelift w202 c230k for 10yrs and this fault has remained throughout the whole ownership
If not already please Subscribe 🙂👍. Interesting so even if you blip the throttle to WOT it doesn't fully close? On gentle throttle application they often don't like to fully close when stationary. Have you ever tried running a boost gauge on it just too see what pressure you are making? Typically stock should be around 0.5 bar I have found as an average. To remove the bypass valve you would need a de-cluched Supercharger pulley and at least a 50mm TIAl style BOV, I believe Ndrmini used this method on his Slk. The other idea I have mulled around is switching to a large vacuum operated bypass valve. Something like this www.ebay.co.uk/itm/304-Stainless-Steel-Bypass-Valve-Exhaust-Control-Valve-Boost-Vacuum-Activated-/313534516142?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=710-127635-2958-0, but with the use of a different actuator like one from a mini cooper s (SC) bypass valve. This is only an idea and would still require a de-cluched Supercharger pulley. But you can lock the standard pulley but the ECU might not like this method as I think your supposed to use a resistor to trick the ECU into thinking the clutch pulley is still there. On our turbo Slk we just unplugged the pulley and the bypass valve and never had an issue, I'm just sharing the correct way to lock the pulley. That's the best ideas I can share with you on that one buddy. 🙂
Iv had the pulley on a switch for few years now, even though iv fitted new OEM pulley and clutch assembly, so would it be possible to leave it on the switch for the clutch and still unplug the bypass to get boost, iv also just seen a vid on here saying a MOSFET in the ECU could be the problem (this also caused the bypass flap not to work!! Once again so grateful for your time.
Oh nice so that makes it a lot easier to go down the vacuum operated route, and that is true there is a MOSFET that on the ECu that can fail it's rare but it does happen. However symptoms with that I believe to be related to the clutch pulley more than the BPV itself. Have you ever tried any kind of re calibration on the bypass valve? Also do you have SDS? I know most people don't due to the expense of it initially but owning these older cars it does soon pay for itself. Also it sounds like other than remaining partially open the valve itself is working as it should which is where I think a calibration issue may arrise, I'm sure there's a way to do it without SDS also.
@@M-oneeleven-M111 Having the same issue here, its throwing a code for it as well. Drives fine otherwise, though the VVT is kaput and I'm still tracking down parts. Have tried the range calibration / reset multiple times with no joy, it does move through the full range of motion though. Tickling 200k miles now, so I'm about to do MAF and MAP anyway, which affect operation? Do you know of any other components or issues that could affect the bypass itself? Thanks for the channel, already learned loads that will help me keep the old girl on the road.
If that plug is not connected to the bpv then the supercharger will not engage, unless someone has locked the supercharger pulley however when people do that it can cause harmful damage as the fuel trim is not right. but I suggest plug it back in as it should be, then check to see if the supercharger engages as it should. if you need to see how the supercharger pulley engagement works or looks like refer to the video on my channel. I hope that helps thanks for watching and if not already please subscribe and share it is all I ask in return for the advice I give thank you 🙂
Does the bypass valve open when you let of the throttle? So let's say I drive and get up to 5k rpm, then let of the throttle, does it open the bypass valve?
Yes every time you let off the throttle it will open and if it's not under high load the bypass valve will be open anyway. As you can see in the video the bypass valve only shuts fully under high load, so whilst driving you don't need to rev it so high to get it fully shut as there is load on the engine this load isn't present when stationary which is why the valve behaves differently. If the Bypass Valve didn't open when off throttle it causes back pressure which puts strain on the rotor bearings and can cause catastrophic failure of the Supercharger if it occurs for a long enough period of time. If not already please subscribe 🙂
@@M-oneeleven-M111 Thanks! Was looking for more info on the bypass valve for my engine swap. I'm using a standalone ecu. So I'm trying to figure out the stock behavior to program it the same.
@@dutch.190e ah right yeah I got you, so the whole system is load based on this car I did do an explanation video about ago that explains a bit about how the throttle body and bypass valve work together. It's very rare on the stock set up that the bypass valve is actually fully closed and when it is it's only for a short period of time. So basically if you keep your foot flat to the floor initially throttle body is wide open and the bypass valve is closed, as you pick up speed and there less load (pedal still to the floor) the ECU will start closing the throttle body and opening the bypass bleeding off boost.
At a standstill it will not close unless you rev it quick and hard as you saw in the video, is it's still not closing it is possible that your bypass valve has failed. When these fail it tends to revert to the open position for safety, but also when the fail (if you still have a clutch pulley) they also should disengage the Supercharger. Does the car feel like it is making boost when driven or does it feel slow off the line? Also please subscribe if you find any of this useful 🙂
hi buddy sorry for the slow response, if the bypass valve is stuck open but the supercharger is still engaging as it should, it is likely the bypass valve motor has failed sometimes they can be repaired but an advanced electrical knowledge is required. these valves are known to fail, however if after replacing the unit the problem continues in very rare cases some transistors in the ECU can be the cause. I hope this helps buddy.
I hope you answer, I need to know, my slk230 supercharger is always on, the magnetic field rotates even at idle, I did not see the bypass valve closing when I gave gas, I do not know if the problem is the supercharger or the valve, it just gives P0806 clutch position sensor fault.
Hi, the bypass valve will not close if the ECU sees any problem with the supercharger or air intake system, the clutch staying engaged is a unique problem to have as normally the clutch fails causing the supercharger to not engage. So there's a few possibilities of problems. Has the supercharger been like this since you bought the car or is it a new issue? The reason I ask this is it is not uncommon for people to lock the clutch pulley. If this is a new problem it's possible that the ECU is actually at fault but this is rare. Is it possible the wires for the supercharger are damaged or it could simply be that the clutch pulley has failed and somehow managed to lock itself. The outer part of the pulley will rotate at idle however and the inner should only engage after around 1800-2500 rpm when the engine is unloaded (static revving) there is a video on the channel and many more on UA-cam showing the standard engagement of the supercharger just to be sure that is indeed always on. But if it is giving you a fault code for it that's a pretty good indicator, it is very rare for one of these pulleys to have such an issue unless someone has previously locked the pulley using the washer method inside the standard pulley.
I have problem with bypass valve,magnet on my sc clutch burnt and i make it clutchless and unplug the clutch wiring and now the bypqss valve doesnt work its just stuck open
This is because the ECU is in its "safe mode" when it reads boost at incorrect point so if it sees boost at idle that's a overboost situation, so to protect the engine the ECU opens the bypass valve to vent as much boost as possible as it can't control the boost. The only way around this is to make a 50mm butterfly style vacuum operated valve. You need a eBay or Amazon vacuum exhaust valve a manual boost controller some t pieces and vacuum lines. There are some videos on the channel of this, but it takes time to manually adjust the boost controller to slow down the valve closing so the car works normally otherwise it can run rough. The only other issue with this is the car then runs on a naturally aspirated fuel map rather than the adaptive map under normal operation. The only right way to fix this is a new clutch pulley unfortunately but you can mask the issue with a vacuum valve, a normal BOV style valve will not work in my experience. I hope this helps
@@M-oneeleven-M111 i have installed a clutchless SC pulley but i removed the electronic part of the clutch and fixed it on the engine bay, still connected to the BPV.
The power has gonne up and the ECU sees no problem with it, as it is still sending the signal to the "clutch" and opening/closing the BPV when needed
Power has gonne up and so i thought the boost would have gonne up aswell, but when i installed a boost gauge, it now reads 0.5bar which, from what i've heard, is stock...
I've dynoed the car and im now making 212hp and 335Nm of torque
How is this possible if i'm making the same boost as stock?
I have a clk 230k m111.975
I forgot to mention that the reason it's making more power is because im using a smaller SC pulley, so it should make more boost as far as i know because it is rotating at higher rpms, but maybe im missing something?
I think I might have problems with mine, Is this a "safe" way to test it. removing the tube, starting it and revving it? (I have a SLK200 1998 R170 M111.943)
I'm very sorry for such a late response you may have already tested it by now unfortunately I don't always get notified of comments. Without DAS/SDS this is the only way to really test the bypass valve unfortunately. You can check with it removed from the airbox by just turning the ignition on the valve will actuate. But to test properly this is the only real method. This is a safe way to test aslong as you make sure there is nothing loose that can fall or be drawn into it, this is because the engine draws through here prior to the Supercharger engagement. Once again I sincerely apologize for the mega late responce
Hello and thanks for these videos my current code is a P1235 researching and cant seem to figure this out The compressor is not pulling in and the air flap is not operating
I installed a used flap it also is not working.
I recently got the car after sitting for 4 years with a head gasket failure, its all sorted now
replaced fuel filter plugs, coil packs ,wires and injectors. fuel pressure is ~55PSI
The Vanos plungers was a bit sticky when putting it back figured it didn't have any oil not sure if it's related.
Any thoughts on a fix or test I have a Launch .X431 tool
1999 SLK 230 US version
Thank you I hope they help, for anything where the supercharger does NOT engage this is usually a sensor related to fuel mixture so MAF sensor, O2 sensor or its the bypass valve. The most common thing on these cars is the MAF sensor failure due to oil contamination and this causes the same issues. In these cases the MAF sensor should always be replaced with a genuine Bosch sensor, however you can sometimes clean them I have a how to on the channel. Sometimes cleaning them can be enough to get them working again. Second to that is O2 sensor failure but less common but as the headgasket has failed before it may have damaged the O2 sensor. Thirdly is the flap which you have replaced, Fourth is the clutch pulleys can sometimes fail, but not that often and in super rare cases the MOSFET transistors in the ECU that control it can fail but this is very rare! I hope this gives you some idea where to go from now, thanks for watching 👍
I really want that hiss Sound but how do i get it
There's two ways you can make a blocking plate there is a video on the channel it's not the recommend way of doing it due to unfiltered air being able to enter the system, but I shall give you the link to that: ua-cam.com/video/xmEu6i-Nb7k/v-deo.html .... Then there's the Better way that if you have the tools already doesn't cost a thing it requires two airbox mods that will also improve top end performance :ua-cam.com/video/oqMHZ-T-kEg/v-deo.html firstly do that mod it takes out the restriction on the intake secondly do this mod: ua-cam.com/video/An0uOoezuUg/v-deo.html then for even more noise you could use a Pipercross foam panel filter. If you go with the airbox option be sure to make the holes where I did on the wing/fender side of the airbox as it's the coolest area of the engine bay, obviously drawing in warm engine bay air is not ideal but to be honest I never had any negative effects. The stock intercooler is the biggest problem for high intake temps anyway. Also taking the air guide out for the diverter valve does cause turbulence in the airbox but again you did not notice it. Also if not already please subscribe 👍
Hi is there any way to remove or bypass the bypass valve, iv got a new genuine Bosch maf sensor and iv tried 2 different bypass valves both do a self test with ignition on, neither close on full revs whilst stationary, iv heard some mercs suffer from problem in the ECU causing bypass valve not to operate, any and all advice will greatly be appreciated, iv owned my pre facelift w202 c230k for 10yrs and this fault has remained throughout the whole ownership
If not already please Subscribe 🙂👍. Interesting so even if you blip the throttle to WOT it doesn't fully close? On gentle throttle application they often don't like to fully close when stationary. Have you ever tried running a boost gauge on it just too see what pressure you are making? Typically stock should be around 0.5 bar I have found as an average. To remove the bypass valve you would need a de-cluched Supercharger pulley and at least a 50mm TIAl style BOV, I believe Ndrmini used this method on his Slk. The other idea I have mulled around is switching to a large vacuum operated bypass valve. Something like this www.ebay.co.uk/itm/304-Stainless-Steel-Bypass-Valve-Exhaust-Control-Valve-Boost-Vacuum-Activated-/313534516142?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=710-127635-2958-0, but with the use of a different actuator like one from a mini cooper s (SC) bypass valve. This is only an idea and would still require a de-cluched Supercharger pulley. But you can lock the standard pulley but the ECU might not like this method as I think your supposed to use a resistor to trick the ECU into thinking the clutch pulley is still there. On our turbo Slk we just unplugged the pulley and the bypass valve and never had an issue, I'm just sharing the correct way to lock the pulley. That's the best ideas I can share with you on that one buddy. 🙂
Iv had the pulley on a switch for few years now, even though iv fitted new OEM pulley and clutch assembly, so would it be possible to leave it on the switch for the clutch and still unplug the bypass to get boost, iv also just seen a vid on here saying a MOSFET in the ECU could be the problem (this also caused the bypass flap not to work!! Once again so grateful for your time.
Oh nice so that makes it a lot easier to go down the vacuum operated route, and that is true there is a MOSFET that on the ECu that can fail it's rare but it does happen. However symptoms with that I believe to be related to the clutch pulley more than the BPV itself. Have you ever tried any kind of re calibration on the bypass valve? Also do you have SDS? I know most people don't due to the expense of it initially but owning these older cars it does soon pay for itself. Also it sounds like other than remaining partially open the valve itself is working as it should which is where I think a calibration issue may arrise, I'm sure there's a way to do it without SDS also.
@@M-oneeleven-M111 Having the same issue here, its throwing a code for it as well. Drives fine otherwise, though the VVT is kaput and I'm still tracking down parts. Have tried the range calibration / reset multiple times with no joy, it does move through the full range of motion though. Tickling 200k miles now, so I'm about to do MAF and MAP anyway, which affect operation? Do you know of any other components or issues that could affect the bypass itself? Thanks for the channel, already learned loads that will help me keep the old girl on the road.
I've just brought an slk and noticed the wire plug that connects into the bpv isn't connected?
If that plug is not connected to the bpv then the supercharger will not engage, unless someone has locked the supercharger pulley however when people do that it can cause harmful damage as the fuel trim is not right. but I suggest plug it back in as it should be, then check to see if the supercharger engages as it should. if you need to see how the supercharger pulley engagement works or looks like refer to the video on my channel. I hope that helps thanks for watching and if not already please subscribe and share it is all I ask in return for the advice I give thank you 🙂
Does the bypass valve open when you let of the throttle? So let's say I drive and get up to 5k rpm, then let of the throttle, does it open the bypass valve?
Yes every time you let off the throttle it will open and if it's not under high load the bypass valve will be open anyway. As you can see in the video the bypass valve only shuts fully under high load, so whilst driving you don't need to rev it so high to get it fully shut as there is load on the engine this load isn't present when stationary which is why the valve behaves differently. If the Bypass Valve didn't open when off throttle it causes back pressure which puts strain on the rotor bearings and can cause catastrophic failure of the Supercharger if it occurs for a long enough period of time. If not already please subscribe 🙂
@@M-oneeleven-M111 Thanks! Was looking for more info on the bypass valve for my engine swap. I'm using a standalone ecu. So I'm trying to figure out the stock behavior to program it the same.
@@dutch.190e ah right yeah I got you, so the whole system is load based on this car I did do an explanation video about ago that explains a bit about how the throttle body and bypass valve work together. It's very rare on the stock set up that the bypass valve is actually fully closed and when it is it's only for a short period of time. So basically if you keep your foot flat to the floor initially throttle body is wide open and the bypass valve is closed, as you pick up speed and there less load (pedal still to the floor) the ECU will start closing the throttle body and opening the bypass bleeding off boost.
Hi,mine does not close when i rev...any idea why?
At a standstill it will not close unless you rev it quick and hard as you saw in the video, is it's still not closing it is possible that your bypass valve has failed. When these fail it tends to revert to the open position for safety, but also when the fail (if you still have a clutch pulley) they also should disengage the Supercharger. Does the car feel like it is making boost when driven or does it feel slow off the line? Also please subscribe if you find any of this useful 🙂
My bypass valve is stuck open supercharger it’s engaging correctly any suggestions? Thanks in advance
hi buddy sorry for the slow response, if the bypass valve is stuck open but the supercharger is still engaging as it should, it is likely the bypass valve motor has failed sometimes they can be repaired but an advanced electrical knowledge is required. these valves are known to fail, however if after replacing the unit the problem continues in very rare cases some transistors in the ECU can be the cause. I hope this helps buddy.
@@M-oneeleven-M111 thanks for the info I’ll replace the bypass valve and see if that solves my problem hopefully lol
@@anthonylpz758 no worries, hopefully that will fix the issue they're fairly cheap to buy good used ones 👍