Does your E9X M3 smell like Fuel? It's probably this

Hello all! I figured I'd post here since I ran into this problem and didn't find any threads here.

I was driving one day and I started smelling unburnt fuel when I had my windows down. After parking I walked around the car and discovered it was only smelling from around the passenger's side rear tire.

Turns out my fuel transfer pump assembly had a crack on the top which was spewing gas onto the top of the passengers side of the gas tank, causing the gas smell on that side.

I ended up finding out that this is a common 3 series issue, the repair process is identical, but the parts are different for the m3.

Save some money and DIY!

Here's a great video on how to fix it:

If you'd rather read, here's an article:

https://bmwrepairguide.com/bmw-e90-fuel-pump-replacement-2007-2013-3-series-fuel-filter/

Note:
The instructions say to replace both the fuel transfer pump assembly and the fuel pump assembly (opposite side of the tank) at the same time. I initially ignored this. And then like clockwork my fuel pump assembly started leaking fuel 3 weeks after I replaced my fuel filter assembly.

I highly recommend getting a tank ring removal tool. It will speed up the repair by at least an hour. Trying to remove the rings without a tool is doable but an incredible pain in the a**

This can be a quite a scary and messy repair if your tank is full of gas. The m3 makes it impossible to syphon from the gas cap. So if you can somehow plan for this repair and not do it with a full tank then try that.

Have fun.

Parts:
Tank ring removal tool:
https://www.amazon.com/dp/B004FDL3BS?ref=ppx_pop_mob_ap_share

Fuel Transfer Pump Assembly
https://www.eeuroparts.com/Parts/404887/Fuel-Transfer-Pump-w-Filter-16112283495/

Fuel Pump Assembly
https://www.eeuroparts.com/Parts/85492/Fuel-Pump-Assembly-16112283497/

Nice! I had this replaced soon after I bought my car (couple years ago), but helpful in case I ever run into this issue again.

After my Indy shop replaced it the smell went away, but I've noticed my fuel gauge isn't super accurate (after filling full tank it'll drop to 3/4 tank within 20 miles and stay at 1/2 tank for 100 plus miles)..no idea if it's related or not

E92_Emma3 wrote

Nice! I had this replaced soon after I bought my car (couple years ago), but helpful in case I ever run into this issue again.

After my Indy shop replaced it the smell went away, but I've noticed my fuel gauge isn't super accurate (after filling full tank it'll drop to 3/4 tank within 20 miles and stay at 1/2 tank for 100 plus miles)..no idea if it's related or not

Weird! I'm no expert but I'd imagine it's one of the floating bobbers on either side of the tank acting up. Maybe it gets caught on some tubing that's in the wrong place.

You could go through that process to take things apart and take a look. It's a pain though tbh but it's doable if it's bugging you enough.

Id absolutely say its the level sensor float being in the wrong orientation or getting caught up in some of the tubing.

Thank you for the great post here.

My spouse smelled gas outside of my car a few weeks ago, but I couldn't smell it inside nor under the hood so I brushed it off. However, after a friend also said the same thing, I decided to check the garage 30 minutes after a nice drive where the car fully warmed up and the smell was pungent.

After searching the forums and seeing this thread along with some others about stuck open fuel injectors, I was fairly confident it must have been either the fuel pump or transfer pump assembly (mainly due to the smell not being present under the hood at all). I ordered all 3 suggested items since I'm close to 135k miles now and figured if it wasn't this I still should replace them. We found some gas on top of the transfer pump casing during the process so I'm sure that was the source.

Overall this is a fairly simple project (~2 hours total). The amazon tool is a bit of a pain but gets the job done for much less than the BMW specific removal tool. The youtube videos do make it look much easier, but that's likely because they filmed on new parts rather than actual 15 year old parts where everything is super tight.

accarter Thanks for the video, tips and parts links. Those links no longer work but these two below do in 2026.
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https://www.fcpeuro.com/products/bmw-fuel-tank-sender-assembly-left-16112283495
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https://www.fcpeuro.com/products/bmw-fuel-pump-assembly-16112283497
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It's cheap insurance to replace both units given the injector service life issue for the S65 and mine has started to have the "slight smell of gas" after filling up around the driver's side rear wheel well.