My M3 is leaking fluid from the driver side front wheel..

[ChewToy]

The M3 had been sitting for over a week (it sits a lot). I pulled it out this morning because I need to put a new diff seal in it because it has a slow leak. Well I pull out and can't help but notice a puddle that was at least six inches wide but not very deep. I put my finger in it and it smelled like gas. From my guess it's coming from the driver side right around the front wheel, maybe a little behind it but definetly on the driver side half way from the wheel to the center of the car. Anyone have any ideas on what it is? I wonder if the race gas I had put in it a few weeks ago had anything to do with this. Help me figure out what this is before I take it to my mechanic later this morning. I want to at least give him some ideas if I can. Tia.

Btw.. where is the left side fuel sending unit located? Could this be my culprit?

[sped here]

Look at the fuel filter lines/hose clamps right under the driver seat/footwell

[ChewToy]

Thanks! I'll have my mechanic check it out. What you described could very well be the culprit because that is exactly where the drip appears to have come from. Any idea how major this is? And what replacement parts I may need?

[Hellrot]

It's common for power-steering fluid to leak there as well.

[Ron17]

What color is the fluid that was leaked?

[ChewToy]

Can this be multiple choice? What do I have to choose from? I didn't really pay tooo close attention to the color but it did smell like gas.

[vjlax18]

If it's right under the driver's seat, check the rubber hoses going in and out of the fuel filter.

[GQ_Style]

Here's my thought. If it was really gasoline that was leaking from your fuel filter, it would not have made and stayed a puddle for days. Unless the leak is still occuring and you would see it. The longest that a small puddle of gasoline would last at temperatures above 50 degrees is about 2-3 hours and it would all evaporate away. It would also stink like gas and you will know it because you think you were choking. A large puddle emits a LOT of vapors.

If it is still there and there is no leak, I'm thinking it is another fluid. The only other common leak on E36 cars is the power steering fluid. This can be clear or red (clear if power steering fluid was used, red if ATF is used). This will stink like machine oil. If your power steering components are stock, my bet is that you have a power steering hose leak (even if this puddle is not from your power steering).

Check those first. Let us know.

[monterey]

When it rains, it pours! Maybe you damaged something during the last fender bender?

[hc1001]

if it was gas ur garage would smell of it like GQ said... the fuel filter is under a plate right under the drivers seat.... u can jack up ur car or soemthing and take off the plate ad inspect the fuel filter, hoses and clamps.... it might be teh power steering as someone else mentioned... but i dunno anything about that...

[ChewToy]

The liquid that was on the ground has evaporated and is almost completely gone. So that points to gas and not oil.. right? My mechanic said the fuel filter hoses looked pretty brittle and needed to be replaced and he suggested I swap out the fuel filter as well. How often should you switch out the fuel filter?
Is this pretty common? Is there anything else I should replace while I'm down there?

[monterey]

I like to change mines every 30K. That's about all you can do while you're in there...

[JamesM3M5]

Yes, the lines dry-rot and crack. Replace them ASAP. You can buy BMW high-pressure fuel hose by the meter at most dealers, or you can get it in 18" sections at the local AutoZone or Advance Auto. Other small-chain auto parts stores usually have 5/16" (8mm) Gates fuel injection hose by the foot.

[John H]

Replace the hoses and the filter. Sounds like your mechanic is on the right track...

- John

[ChewToy]

Thanks guys the parts are already in. Can anyone explain why I haven't seen it leak since that day?