Rough Idle Issues :( - MBWorld.org Forums

Feb 9, 2020 | 06:14 PM

Haji3978

Thread Starter

Junior Member

Joined: Dec 2019

Posts: 56

Likes: 25

C63s Coupe

Rough Idle Issues :(

Hi Guys,

New to the Forum, haven't posted anything up until now.

My car has a rough idle but drives fine even when I push it hard, it has a stage 2 - Down pipes, tune and BMC filters.

I took it to a performance shop and the guy thought it may be the tune so he flashed it stock but the rough idle is still there with factory tune.

Any ideas? Spark plugs? Coil packs? no CEL except the P0420 & P0430 becasuse no CATS.

Thanks

Feb 9, 2020 | 08:36 PM

C3504matic

Senior Member

Joined: Oct 2013

Posts: 418

Likes: 90

From: Edmonton AB

2015 C63S ,DME Tune, KW Has ,Kmac Bushings,BC Forged wheels,Gt Rotors,Porterfield R4S,Modal Intake

Could be plugs as tunes will eat them up .....I'd change those first

Feb 9, 2020 | 10:26 PM

Haji3978

Thread Starter

Junior Member

Joined: Dec 2019

Posts: 56

Likes: 25

C63s Coupe

Thanks bud, booked into Mercedes for a change

Feb 10, 2020 | 06:26 AM

tekfoc

Super Member

Joined: Sep 2014

Posts: 851

Likes: 113

From: NYC

18 E63S

Have coil packs checked also
There was a bad batch in the pass
They were all replaced on my car

Feb 11, 2020 | 12:06 PM

Stevestil

Member

Joined: Jun 2019

Posts: 229

Likes: 58

From: New York, NY

2020 C63S Coupe , 2014 BMW M5

which tune are you running

Feb 11, 2020 | 05:59 PM

Haji3978

Thread Starter

Junior Member

Joined: Dec 2019

Posts: 56

Likes: 25

C63s Coupe

Thanks @C3504matic turned out to be one spark plug that was causing the issue - Mercedes replaced it under warranty

- idles smooth again!

@Stevestil - Car was tuned by theses guys https://dyneperformance.com.au/ - im looking at getting it re-tuned though - Id lobe to get a DME tune but they are so expensive.

Thinking of going to see Gordi at https://etunersmotorsport.com.au/ - Heard he does some magic for the C63s

Feb 11, 2020 | 06:54 PM

BMS

Former Vendor of MBWorld

Joined: Dec 2005

Posts: 827

Likes: 152

From: Simi Valley, California

2018 C63 Sedan

Easy fix!

Plan B could be to throw a JB4 on top of your existing flash map if you just want to dial it up (or down) a little.

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Feb 11, 2020 | 08:44 PM

Haji3978

Thread Starter

Junior Member

Joined: Dec 2019

Posts: 56

Likes: 25

C63s Coupe

Not really a fan on piggy back stuff @BMS - I've texted Gordie just waiting on a reply on when I can take it in. In the interim I hope the cat less P0420 & P0430 CEL codes don't cause issue to my engine

...

I've been reading about the different tunes available and the different power outputs - wonder how some tunes are making extra power without getting heat soak hmmm.....

Looks like the DME tune is the most aggressive and most power making tune from what I read