IAA-C63

When I rev my c63 while in park, there's sometimes an explosive noise. Is this backfiring? What causes it? Does it reflect a problem with the car? Does it harm the car?

_AMG_

Its normal. Nothing to be worried about.

unixadm

Normal when cold. I caught up to my buddy when we left work one day and my car was still fairly cold. I wasn't getting on it, but I clicked off a manual downshift into second gear which resulted in a backfire with flames coming out the drivers side pipe from what my buddy said.

IAA-C63

Scary to imagine flames coming out!

Both times I had backfiring, the car was cold. I'll try again when the car's warm, and will report back on the results.

Part of what worried me was that I ran across several videos of people revving their C63s while parked, and there was never any backfiring. In several cases, the people had just started their cars, but of course that doesn't mean they were cold.

Tackleberry

All part of the show.....!

Infact the hotter they get the more popping and banging on over run. Great fun in tunnels and built up areas....

azadian22

I have heard my car backfire all the time even when its not cold, if I come up to a stop sign or light after I been getting on it for a lil ill hear the popping and cracking of the car backfireing as it down shifts. I don't think are cars would have flames coming out the exhaust,(if there stock) because of the cats, and mufflers. I think...

IAA-C63

Now I'm confused. Is backfiring more likely when the car's cold or warm?

IAA-C63

Are you sure that sound isn't blippling and burbling? Both of those appear to be normal for the C63, and I think quite pleasant.

The sound I'm referring to is fairly loud and explosive, to an extent that probably most people would find worrisome.

azadian22

No don't get me wrong the sound is better then anything that comes out the B/O...but mayby its just the blipping and burbling, I look foward to that everytime I come to a quick stop lol

Tackleberry

Nothing to be confused about. Hot or cold it dosen't matter. It's what they do.

Due to the nature of it being a high performance, and considering it's size, high revving engine, what you are hearing is the unburnt fuel igniting in the exhaust.

This is an old video, but listen to what happens when the car goes into over run (foot off throttle).

Oh yeah, turn up the volume too.....

http://www.youtube.com/watch?v=FwCwMRDjWGI

alrasheed1991

I have the blipping burbling but some time I hear explosive when down shifting in high RPM

IAA-C63

Sounds more like burbling than backfiring to me, but it's a hard to tell. The noise I'm referring to is really loud and is just a single explosion. Not sure if burbling is just a mild form of backfiring?

Tackleberry

Well if it makes you feel any better, mine backfires loudly too. There's nothing wrong with it, thats how it is.....!

MiamiAMG

That's just our V8 blipping and burbling. Mine does it all the time when i downshift-love it. I use it to scare bicyclists when they carelessly wander into the road.

Tackleberry

Absolutely...! It's all part of the fun of it.....

bluejae

it may have been a rodent that exploded as it was passing by the back of your car... check for remains

jsc1234

this happened to me downhill the lady said my car caught on fire but it went away

Jons95c36amg

Ahh.. the nature of the beast! Someone told me it sounds like a misfire

GMW

http://www.youtube.com/watch?v=Je-scgFJGBc

At the 4 second mark you can hear a small backfire. Car was hot and idling because I just reached home and decided to record it.

Now for those of you who wish to hear the 'big one' at your beck and call then you need to downshift (while in Manual mode) from 4th gear to 3rd gear while slowing down with the rpms coming to, or at 3,000rpm on the tacho. It's also possible around 2,500rpm when slowing down from 2nd gear to 1st, though not as loud but a at a much slower speed. Play around with the rpms around those respective marks/gears. The loudest is the 4th to 3rd gear though! :-)

IAA-C63

OK, you guys have convinced me that backfiring is normal for this car (and other sports cars), and nothing to worry about.

And now we know that the C63 is literally a fire-breathing car!