Back fire?

[M3west]

Noticed when cold in the morning I hear a back fire from somewhere in the middle of the exhaust.

Only once or twice then gone....

I take it this is normal?

 

[M3west]

Hi guys.....


I take it I am alone then?

 

[Coisman]

...what car is this again??

 

[Coisman]

O wait... M3 :flyfun: Sorry :rollsmile:

 

[Stig46t]

not sure from my side,

I know my M5 backfired when MAF sensors where unplugged???

thats all i know, Backfire is normally over-fuelling, so something electronic is miss-calculating imo, so unless u running a re-map with "aggressive" fuelling for extra cooling etc, i dont think it is normal, but i havent ever owned an E46 M3, so can't solve your issue, sorry

 

[M3west]

Thanks for the reply. Car is totally standard. As you might know M3's (especially SMG's) are dogs to drive when they are cold....but just find it strange that I can hear this very "ceramic" sounding back fire when accelerating slowly then backing off.....

not sure from my side,

I know my M5 backfired when MAF sensors where unplugged???

thats all i know, Backfire is normally over-fuelling, so something electronic is miss-calculating imo, so unless u running a re-map with "aggressive" fuelling for extra cooling etc, i dont think it is normal, but i havent ever owned an E46 M3, so can't solve your issue, sorry

 

[calypso]

Cant say its ever happened with my e36 or e46. The E46 can however sometimes be a little jerky for a few seconds at a cold start.

 

[e23]

Would you say it's more like a pop at idle? I only noticed this on my SMG e46 M after doing a spark plug change a few weeks ago

I went from OEM NGK plugs to Bosch & my mechanic said that this "pop/backfire" is common in e46 M's - although I've never heard my car do that b4

Like you, it's only on startup & after the car is warm all is 100z:thumbs:

 

[M3west]

Would you say it's more like a pop at idle? I only noticed this on my SMG e46 M after doing a spark plug change a few weeks ago

I went from OEM NGK plugs to Bosch & my mechanic said that this "pop/backfire" is common in e46 M's - although I've never heard my car do that b4

Like you, it's only on startup & after the car is warm all is 100z:thumbs:

Correct, only happens for the first couple hundred meetings. After that is does not do it again....

 

[UpNcOmiNg!]

Not sure about the backfire, but damn your car looks good in your signature.

We need more pics prior to any more questions being answered :rollsmile:

 

[M3west]

Not sure about the backfire, but damn your car looks good in your signature.

We need more pics prior to any more questions being answered :rollsmile:

:rollsmile:

Thanks man.... appreciate the comment. She just got back (had a bit of work done) She looks almost 100% now !

I will be going on Sunday. You?

 

[Nic_s]

Not sure about the backfire, but damn your car looks good in your signature.

We need more pics prior to any more questions being answered :rollsmile:

:rollsmile:

Thanks man.... appreciate the comment. She just got back (had a bit of work done) She looks almost 100% now !

I will be going on Sunday. You?

He lives up north :thumb:

I by no means know that much about M3's, but from what I understand, when cold the car would run very rich until it starts to warm up a little. So if your M3 also has different plugs like e23's, then that with the running rich while still cold could be why it's back firing :dunno:

Maybe just check what spark plugs is int your M3 right now?

 

[M3west]

Not sure about the backfire, but damn your car looks good in your signature.

We need more pics prior to any more questions being answered :rollsmile:

:rollsmile:

Thanks man.... appreciate the comment. She just got back (had a bit of work done) She looks almost 100% now !

I will be going on Sunday. You?

He lives up north :thumb:

I by no means know that much about M3's, but from what I understand, when cold the car would run very rich until it starts to warm up a little. So if your M3 also has different plugs like e23's, then that with the running rich while still cold could be why it's back firing :dunno:

Maybe just check what spark plugs is int your M3 right now?

Thanks - will check plugs and report back !

 

[riyaadahmed]

Never happened with mine.BTW your car looks awesome dude:thumbs:

 

[M3west]

Never happened with mine.BTW your car looks awesome dude:thumbs:

Thanks man !

check more pics here

http://www.bmwfanatics.co.za/showthread.php?tid=30245

 

[Niel333]

I dont think its normal, although I think I know what you mean. I had a couple and one of them did it but I traded it in like that....

 

[kav]

hi. my e46 m3 does the same when i start it for the first time in the morning. Theres a crack/pop emitted from the centre of the xhaust. it only does that once or twice and then its gone!!!
it never crossed my mine that anything could be wrong, cause the car goes just fine. oh and the plugs were changed about two weeks ago so same sympton with old and new plugs!!!
i dont think its something to worry about

 

[Niel333]

I dont think its anything to worry about, I drove mine like that for 6 monts before I traded it in and performance was no diffirent then any of the other. I swopped airflow meter, middle part of the exhaust( thought the cats might be blocked) plugs and there was no improvement. Only thing that changed was the jerk at 2000rpm when cold was gone after airflow meter swop.