Awful smell, burning / fuel dump in sports mode

[Trenbolone_Sandwich]

Hi all,

I have a 2015 BMW M4 F82 with a new issue that appeared this week. When I switch from comfort to sports mode for a brief moment I can smell an awful burnt smell or really strong smell of fuel that I haven’t smelt before. It usually clears up after the initial hit but when I stop the car and get out I can smell fuel. There has been no smoke however my fuel efficiency has dropped by about 12% and stayed steady since. No leaks anywhere on the ground to be seen.

Currently running catless Downpipes but I’ve had them on for 2 years and haven’t smelt anything like this before.

This happened to anyone / anyone have any ideas what could cause this? Contemplating either taking it to BMW or scanning myself for error codes but don’t have the software at the moment.

[N1rve]

Originally Posted by Trenbolone_Sandwich

Hi all,

I have a 2015 BMW M4 F82 with a new issue that appeared this week. When I switch from comfort to sports mode for a brief moment I can smell an awful burnt smell or really strong smell of fuel that I haven’t smelt before. It usually clears up after the initial hit but when I stop the car and get out I can smell fuel. There has been no smoke however my fuel efficiency has dropped by about 12% and stayed steady since. No leaks anywhere on the ground to be seen.

Currently running catless Downpipes but I’ve had them on for 2 years and haven’t smelt anything like this before.

This happened to anyone / anyone have any ideas what could cause this? Contemplating either taking it to BMW or scanning myself for error codes but don’t have the software at the moment.

Smells rich to me. Maybe a stuck fuel injector?

[Trenbolone_Sandwich]

Originally Posted by N1rve

Smells rich to me. Maybe a stuck fuel injector?

Possibly, but the car drives fine. I filled it up with fuel and took it for a solid spin, economy runs just fine, put it in sports mode and thrashed it a bit and had no errors, no idle, no shaking, no nothing, just a foul smell when I first put it in sports mode, after the first acceleration the smell disappears.

Going to take it to bmw to see if they know what it is and then probably fix it myself if I can…