SLK55 AMG 5.5 V8 (R172) - Exhaust Valve Actuator bypass modification plus the noisy test drive!!

Exhaust valve actuator started to fail so decided to fit a valve emulator to keep the valves fully open at all times and at the same time keeping the ECU happy in-check. Keep watching till the end for the test drive to hear the insanely noisy V8!!
#amg #amg55 #mercedes #mercedesamg #mercedesbenz #v8 #slc

[@leonardmein4250]

the man likes it 🤣, cool car buddy

[@leew88]

Thanks

[@NissinKid86]

Sounds insane Unc, makes my MX-5 sound so weak LOL! Nice vid!

[@zactormak]

that sounds nice

[@A_Nonn]

Sounds very nice. I like it too.

[@simonclarke3428]

Great video thanks. I have the same make and model so bought the same device to fit to mine. Unfortunately the off side exhaust valve has failed in the closed position and will not open. Any suggestions?

[@leew88]

Remove the actuator held on by two small bolts from the top, turn the valve open by hand and turn the actuator motor around to match and refit. The valve could also be caked shut due to carbon build-up so may need time freeing it up. Also be aware there is a spring clip mount between the actuator and the valve mechanism, make sure that all aligns up.

[@simonclarke3428]

@@leew88 Thank you, I will give it a go when I get some time and let you know how I get on. Thanks

[@simonclarke3428]

Update. I removed the actuator, it is fixed with 3 bolts. The actuator is actually a servo drive, which seems a bit extravagant given what it's doing. It's not possible to mount it in any other position . My first idea was to open the valve by hand and refit the actuator minus the drive transfer spring, but this would have meant there was nothing holding the valve in the open position and could have been blown shut by the exhaust gases. So I bought a second hand actuator off eBay and fitted that and then drove the valve open disconnected it and fitted the emulator device. When doing my research I found that as it's a servo drive some people fit control devices to enable variable position control. I also found that some people didn't like the sound when running on 4 cylinders, what's your opinion on the 4 cylinder sound?

[@dawoudahmadi1378]

Could you kindly provide me with the part number or a link to where I can purchase the Valve Actuator bypass?

[@leew88]

www.ebay.co.uk/itm/334240338194 It's listed for a VW Golf 7 but rest assured it works on our SLK55 as it uses the same exhaust motor. The price seems to have gone down too which is an added bonus.

[@youngp4116]

Nice car! Subscribed to learn more as I also have an SLK55. How do you know if your exhaust valve actuators are bad? You mentioned that they threw a code(s). Does that also cause the check engine light to come on in the dash? OR do you have to plug in an OBD2 reader to see if there is a fault code?

[@leew88]

Engine will hold back and lose power at around 5000rpm. EML light will not illuminate only soft fault codes are stored which can only be read with a OBD2 diagnostic reader similar to the one I'd used. Sometimes when one actuator fails it will cause the opposite side actuator (working one) to cycle between open and closing as it tries to sync up with the faulty side, so if you hear this continuous cycling when you turn the ignition to no 2 without starting the engine then the other side actuator is faulty. Bare in mind you may also have other symptoms like short or open circuit fault codes which may not be obvious without a code reader, hope this helps.

[@youngp4116]

@@leew88 thanks for the info! One other question. If one goes bad, I've read that when the key is in the ON position but car not actually started, the flap actuators will make whirling sound as the good one tries to sync with the bad one. If both are good, do they still whirl when car is on but not started?

[@leew88]

@@youngp4116 If both are good you shouldn't get any constant noise other than the initial flap movement pre-start.

[@franck7302]

Thank you very much for your video. Can you tell us where have you buy the emulators ?

[@leew88]

Bought mine from a UK eBay seller as shown on the clip near the beginning of the video or search for VW Mk 7 Golf R exhaust valve delete. It's sold for VW but also works on our R172 SLK55 as it uses the same valve actuator.

[@franck7302]

@@leew88 thank you 🙏

[@cerberus_uwu]

quality diagnostic kit you've got! LOL!! - 'shirt circuit' FFS! - do yourself a favour and ger an AUTEL AP200 :)

[@leew88]

@@cerberus_uwu I was waiting for someone to notice that.. 😂

[@christinalloyd9566]

Thanks for the video. Very useful information. I have an R172 SLK55 as well. Something I find annoying is that I like the cylinder de-activation feature to 4 cylinders in eco mode but what I don't like is that you have to have stop-start on as well. I haven't found a way to turn the stop-start off without also turning cylinder de-activation off. Any ideas?

[@leew88]

Hi Christina, I have the exact same idea as you, however I'm kind of fortunate that my stop\start never worked since I purchased this vehicle 6 months ago even though the ECO button green LED is always on and the ECO8\ECO4 cylinder de-activation and brake HOLD function still works as intended. I've researched into this quite a bit and found that the previous owner had fitted a bog standard 12v 80ah flooded battery (rather than the AGM version), so the car has intelligently recognised this situation and disabled the stop\start function whilst keeping all the other functions to work as intended. The 12v 10ah auxiliary battery behind the passenger seat had also been swapped out but I don't think this is the reason it has disabled my stop\start as they had installed the correct AGM 12v 10ah replacement. I will be doing some coding \ programming videos in the near future of some of the features which I've activated already, so I'll take the opportunity to see if this can be coded out without effecting the other functions, watch this space.

[@christinalloyd9566]

@@leew88 Thanks a lot for your reply. Very interested to see your future videos!