cz63

Bump. Did anyone end up finding a better solution to this issue at all?

My '17 63S recently came out of warranty and then the valve started playing up.

Guys who did the spring stretch trick... is that still working out okay?

Thanks, Matt

Jimmy_c63s

Deleted

Humzahali

Dear all,

I am having the same issue many have experienced.

I have taken out the h pipe and replaced with a pipe (without the disc in the middle)

can I weld the original part back on and close the valve affectingly?

do I need to use a simulator or can the original accuator work?

please if anyone can assist would much be appreciated.

Humzahali

Dear all,

I am having the same rattling issue many have had and I am currently stuck with what to do.

so what I have done since is cut the H pipe where the flap is inside and replaced it with a new pipe (without a flap). This obviously is still causing issues.
What options do I have?

option 1 - the original flap close it and weld the original pipe back to the exhaust? If so can I use the original accuator and plug in or will I need to replace it with a AWE simulator?

If anyone can assist I would really appreciate it as this exhaust issue is causing me a lot of stress.

thank you

Speeddoc

I will be getting my 2021 C63S coupe in about 2 weeks. Waiting for it to clear port customs and then get delivered to my dealership. Can anybody comment as to whether the 2021 models have addressed this H-pipe valve issue so that it no longer needs to be additionally addressed after the fact? Has this rattling/insufficiently tight spring for the motor that actuates the H-valve flap been definitively addressed on the newer cars?

Jimmy_c63s

Why is it causing so much stress?

Close it.

You need to close the flap permanently so it's blocking the pipe then weld it back in then use the AWE simulator to prevent the CEL on the dash.

It's been explained by @untamedd many times.

Mods please merge with this topic.

Humzahali

@Jimmy_c63s Hi Jimmy, thank you for the response, I am uk based and struggling to get hold of a AWE simulator. If you can provide a website which delivers to uk I would much appreciate it.
Also I have replaced the h pipe valve section with a new pipe. So at the moment the h pipe section has no valve/disc inside at all.

1. I close the original flap and weld back on and plug the simulator once I get hold of it

2. Place a disc in the new pipe and plug simulator

please advise?

Humzahali

@Jimmy_c63s This is what I have taken out and replaced with a pipe

Humzahali

@

Jimmy_c63s

Twist the valve and make sure the disc is in closed position so it looks like it's blocking the pipe.

Weld it shut.

Then put it back on the car and either get an AWE Simulator or get a Mercedes specialist/Indy workshop to code out the error. It can be done through coding or using the AWE simulator. Either one.

Have you noticed your car doesn't sound the same with the new hollow pipe in place? Lost it's growl?

dctwc63s

Just out of curiosity, is the valve on the h pipe suppose to be open or closed during WOT?

Humzahali

@Jimmy_c63s thank you I will give this a try.
simulator has been ordered.
We unplugged the valves at the rear and when I did that the power was limited to 350 hp max, felt like it was in limp mode, so roadside came out and done a update, plugged the valves at the rear back in.
With the new hollow pipe there is no growl which is very irritating. You reckon it’s because of the hollow pipe or there is no flap/disc inside?

originally I took the h pipe valve out and got it welded open but obviously now reading the above it should be closed, hopefully the exhaust place can weld it closed with no issues.

Thanks for your help

Jimmy_c63s

Yes, when the H-pipe valve is open it makes the car sound less throatier.
When the H-pipe valve is closed, the sound will be full and proper.

So make sure you weld that valve to be permanently closed before putting it back.

With the simulator plugged in it will stop the car from going into limp mode.

ShaneN.

Rather than welding an h valve shut, why not cut up down & down stream of the exhaust, totally eliminated the whole h pipe section (not just the valve) and the then have one clean straight piece of pipe welded in on each side. Better flow and cleaner look/job. Obv using an awe sim too.

Jimmy_c63s

Unfortunately if you do that and completely eliminate the H-pipe it'll alter the sound and make it sound crap.

The H-pipe being there actually does something for the sound of our cars. I've been reading up about it on the German forums.

Which is why the preferred solution is to remove the rattling H-pipe, weld the disc (flap) into the closed position and reinstall the H-pipe locked in closed position, then unplug the actuator and use the AWE simulator or code it out.

Hopefully we hear back from the OP once he's done it, too 👍

ShaneN.

I wonder why as you're essentially straight piping it at that point anyways, the h pipe won't be merging exhaust gases. Weird.

Humzahali

@Jimmy_c63s
we have shut of the valve. But waiting for the simulator to be delivered. AWE are currently out of stock and it will take 4 weeks! I was still thinking to get the h pipe welded in now, I’m sure it will do a better job then the current hollow pipe.

Jimmy_c63s

Get it welded in and take the car to a Mercedes tuner who can code out the error for you.

4 weeks is too long.

Humzahali

@Jimmy_c63s
i will get this done tomorrow. I will let you know how I get on.

Jimmy_c63s

Good luck with sorting it out mate. Waiting to hear back.

Humzahali

@Jimmy_c63s
Latest update

Got the H pipe welded back on and plugged in the accuator/valve,finally I have the exhaust sound back! I would say it’s much more louder when upshifting.

1 issue left, I’ve taken it to 2 ‘tuners/coders’ both placed diagnostic machines in, can’t seem to find any sort of codes.

It is weird since welding the originally h pipe and plugging in the acciator/valve, I am seeing 500 hp when putting my foot down.

I will see if mercedes can plug their machine in to see if they have any codes pop up.

In the meantime I guess I will have to wait for the simulator.

Jimmy_c63s

There you go mate.

Did you test the car in Sport+ and Race mode after plugging in the welded H-pipe valve? Be sure to do so and see if that throws any codes or puts it into limp mode again.

Humzahali

@Jimmy_c63s
cars always in sport + or race
I will give the car a few runs tonight.

from my understanding if your car is in ‘soft limp mode’ it should only be providing 350
hp max , I am 100% getting 500hp?

slightly confused, I guess I’ll drive it tonight and see if I’m experiencing any sort of loss of power

CCMoney

I’m wondering if the Renntech EVM would do the same as the AWE simulator and save me from a CEL or limp mode… anyone have an idea on this?

The rattling in my 2018 is starting to really bother me and I’m exploring the idea of welding the H pipe shut if the Renntech EMV works. Already have it installed and don’t want to buy the AWE part if I don’t have to..

Jimmy_c63s

How did you go with the testing? Are you getting full power? Any issues?

You may have just discovered a new trick 🤔

So let me get this straight.

You've removed the old rattling H-pipe
Welded the valve into Closed position (so the disc is blocking the pipe)
Re-installed the welded pipe and the actuator motor (with the spring still attached?)
Plugged in the actuator instead of leaving it unplugged and using a simulator

And the car seems to be running at full power and not in limp? Correct?