Greetings from Russia, dear forum members!

I've been reading this forum for a long time and found a lot of useful information and answers on my questions regarding my car, since here in Russia we do not have such a major forum with AMG owners. I've never thought I would create a new thread here but bad things happens...

We have: C63s Coupe Edition 1, 2016, with 34.000 KM mileage.

About a year ago I've decided to do Stage 2 tuning with catless downpipes. In addition to it I had a common problem with a rattle/noize comming from H-pipe valve in the middle of exhaust. So according to a special thread here I've decided to PLUG OFF the actuator and weld the Valve in closed position (some guys here adviced). I did not use any "AWE Tuning Simulators" or something like that. Just pluged the actuator off and fixed the valve in closed position.

Everything went perfect - no errors, cels, boost leaks or something like that for a long time (1 year). To tell the truth I am not a real crazy driver, do not like doing drifting or something like burnouts. Just use my car every day to get to my work and some evening light racings on weekends in a gentle mode. Just like a pensioner 80% of the time As for service - I change an AMG oil and filters every 6.000km and use the best petrol in Russia at the same gas station every time.

A year passed and about 2 months ago I've faced with the first ever problem with my car. I was driving home from my work as always and noticed that something is going to be wrong with my car. It felt like it has 150hp and do not accelerate, like turbos are not working and the exhaust sound was something like "MUTED". I looked at my dashboard fastly and noticed that the boost scale is not rising when I try to accelerate. So I stopped, shutted down the engine and waited for 5 minutes. After that I tried to drive again but nothing has changed, the problem was still there - no boost and muted exhaust. No codes, no errors, no cels. Just the car was not accelerating.

The next morning I arranged a meeting with our local MB Dealer to diagnose this issue but they only could offer me to come in a 7 days due to queue. So i decided before visiting a dealer to diagnose a car at tuning shop near my workplace (those guys have a programm which could diagnose errors from ECU). So we plugged their scanner in and the only one error which we found was and code for exhaust valve #3, it said that it was not working properly. Firstly I thought that this is about my H-Pipe valve which was plugged off and welded, but I used the car for a year and no problems with it shutted down. We decided to clean that code and try to drive a car to see if a boost ptoblem was still there. I've started my engine, went for a quick drive and BINGO - the car was boosting again with no problems like in past.

After a 4-5 days of driving the problem has suddenly occured again - no boost. I've decided to wait till my Dealer's visit. By the day of visitting the dealer I've read too much in this forum regarding boost problems and found the common problem with a vacuum Hose which could be pinched and that will put a car in a Limp Mode. So when I came to a dealer I told hhe manager my symptoms and adviced to check that Hose which I've read about in forum.

The manager forwarded my car to their diagnost who worked for an hour with my car and in the end told me that the only one error he could find is EXHAUST VALVE CODE but as he said it can't turn the boost off! Also he told me that we shuld change a vacuum hose to a new one and a valve / gate which is connected with that hose (do not know how to call it properly, but the pictures are attached).

2 more weeks passed when they called me again to come and fix that details. So they have done it and called me to come and check if the boost is OK. I took my car, made a shor drive and there was still no boost.... I got back to dealer's diagnost and we decided to investigate together. He plugged in their diagnose computer to my car and started to put a throttle down in various regimes COMFORT, SPORT, SPORT+ for a long time. (I do not have perfromance exhaust with a button so my exhaust valves seem to open when the car is in Sport+ as I understand). After that procedure he told me again that there is no codes and everything should be perfect and again "EXHAUST VALVE CODE HAS NOTHING WITH A BOOST OR LIMP MODE". We've decided to make one more drive together with his computer plugged in. And what do you think?! YES - the boost came again and everything went perfect.... So I left the dealer with an agreement that I'll drive and check if the problem comes back.

3 weeks of perfect conditions passed. I had no problems with my boost in all regimes (COMFORT, SPORT+). But yesterday that issue poped up again. No boost and the exhaust sound is something like a MUTED. From that moment I started to think that the exhaust valve code is the main reason my car has no boost. But the dealer's diagnost told me that it has nothing to do with Boost. So I am confused. I came again to local tuning shop to talk to them. They told me that if the actuator or valve itself doesnt work properly - it COULD tell the ECU to turn off a boost. Also they tried to open / close the valve with their computer and we think it did not open + the valve code poped up again.

From that time we decided to check what is wrong with my valve at the end of my exhaust - but these guys are to busy so I have to wait for 2-3 days. So I decided to make a thread at this forum to collect your opinions.

As I understand there should not be a problem with an H-Pipe valve which is plugged off because I drove a car for a long time (a year) and it did not affect my boost. So firstly I suppose it is about exhaust valves at the end of my exhaust.

Maybe someone had any problems with exhaust valves which were stucked, destroyed or something like that which led to a limp mode? Is that possible that the ECU would stop the boost if the valve is not working well?

Actually I've ordered an AWE Tuning Simulators in case the valves are damaged. But do not know if it helps.....

Any thoughts, advices etc would be greatly appreciated!

Best regards

The hose we've changed

The gate's box

The gate we've changed

 

Issues with exhaust valves will trigger a soft limp mode with no boost. AWE Tuning Simulators should help.

 

Hi! Thanks for your reply, hope those simulators will help to solve my problem as I am really upset with that.

 

A quick update:

I've just understood that my exhaust doesnt have valves in mufflers since it IS NOT PERFORMANCE EXHAUST. That means that the error which is stored in ECU is about my H-Pipe valve which was plugged off and welded in closed position A YEAR AGO. Is that possible that the car decided to go into a limp mode after a year of exploitation?

I am confused again, cause I cant understand how I drove a car for a YEAR with no boost problems and only now my car decided that this plugged off H-Pipe valve is a great problem? I suppose that error code for valve was there for all that time since I turned off that H Pipe valve actuator.

Is that really possible that my car decided to go into a limp mode only after a year?

 

The car is 100% in soft limp mode. You can get the H-pipe removal "coded" out by a workshop and if you can't find a workshop that will do it just an AWE Valve Simulator.

You will still need to take the car to a workshop to have the soft limp mode reset. Only a workshop/dealer can do this for you.

 

Thnaks for your help, will try to find a coder who could remove the h-pipe by programming the car. Otherwise waiting for AWE Simulator, which I ordered yesterday but it is likely to arrive to Russia no earlier than in March - so the first option is more convenient.

And if all of this would not help - I have no idea what else could trigger a limp mode because no more error codes, just the valve one

 

Don't worry it's the valve bro. Hopefully you can find a workshop this weekend that can code it out for you? Just make sure they reset soft limp mode too. Have you called around yet? Mercedes tuners in Russia will easily know how to fix this

 

Yeah, actually I have a tuning shop near my working place, in a few hours they will check that valve again and call their coder to come with all necessary equipment Fingers crossed, hope he'll be able to code it or I'll just find another one guy.

By the way I'm being shocked about our local MB Dealer cause their diagnost told me that it is impossible that valve error could trigger something like a limp mode. Moreover he said he really doesn't know what do I mean by "limp mode"

 

Almost all Mercedes dealers around the world are clueless and lazy. Sad!

Let us know how it goes mate!

 

Coming back with latest news

It was not easy to find someone with Mercedes original programm, but finally I've managed to find a guy with that. My tuner who made Stage 2 a year ago is from another city so he connected to my car by Internet and just turned off that valve from the system.

30 minutes of work and BINGO - my car became insane again! Actually I did not beleive that, but yeah, seems to me that this valve really caused limp mode.

Hope the problem is finally solved

Thanks again for your help!

PS: Don't let MB dealers to fix your cars, cause they don't really understand how AMG works....

 

Excellent work my friend. Told you it was in soft limp mode.

Is your valve still rattling when you accelerate? Just leave it plugged in if it doesn't annoy you too much and if you need to, you can always use some copper grease every 3 months to stop it rattling.

 

No boost, I have the fualt code exhaust valve and checked the hose and change the Sinoloid for the vacuum and no change like he did, tomorrow I have an appointment with tuning shop for them to figure out problem but I believe after reading this and the guy at tuning shop also said exhaust code may be throwing off ecu to turbos but the car still feels somewhat loud and button for exhaust still works too and also feels like it does get louder I’m not sure tho but hopefully this is my problem! I also have stock exhaust so I’m not sure if bad margile or what is the issue but the car only has 5K miles and this is also my 1st amg 63 I’ve only enjoyed it in limp mode I guess it’s bought it little front end damage.