Help with gasoline smell but no leaks

The843N54 · 10-03-2021, 10:29 PM

I started my 2008 e92 335i yesterday and after cutting the engine I noticed the smell of gasoline. I let it sit overnight and drove it again today. After coming back and letting it sit again for a few hours, I still noticed the smell. I traced the smell down to the drivers side of the engine bay. The passengers side does not smell like gasoline. I have seen no leaks last night or today in the garage…just the smell of gasoline.

Any ideas?

tcphoto · 10-03-2021, 10:54 PM

The fuel rail runs up the right/middle of the engine under the beauty cover, I would pull it and see if there’s a leak.

marvinstockman · 10-04-2021, 08:39 AM

Fuel injector not closing and leaking into engine.

The843N54 · 10-04-2021, 01:30 PM

Thanks for the suggestions. I'll check both of those.

Update* ran home at lunch and do not smell the gasoline odor anymore. I'll check again after work and update.

RayLivingston · 10-04-2021, 02:38 PM

Gasoline is highly volatile - it evaporates VERY rapidly, even at low temperature. A small leak will leak vapor, which is invisible, but will still have a strong odor, even from a VERY small leak. A larger leak can leak small quantities of liquid, which rapidly evaporate, leaving no visible trace. A much larger leak is required to actually drip enough liquid to persist for any length of time.

If you smell gas, you HAVE a leak, whether you see it or not. You can buy a hydrocarbon "sniffer" to help localize the leak, but you're probably better off narrowing down the location as much as you can by sniffing, then just replacing ALL seals, gaskets, plastic parts and hoses in that general area that COULD possibly leak. In that absence of severe corrosion, there are not that many places the fuel system CAN leak, since the majority of the system is hard steel lines.

IllSic_Design · 10-04-2021, 05:15 PM

Check out the fuel pressure regulator setup in the tank behind the drivers seat. Pop out the rear cushion and remove the cover panel and you'll see it. Common issue is the plastic cracking/breaking and spitting out fuel, mine just recently cracked and I need to replace it asap, decent fuel smell outside the car

Serf27 · 10-05-2021, 12:17 AM

If the regulator is leaking, you’ll get a fuel smell and hardly see it leak.

10-03-2021, 10:29 PM	#1
The843N54 Enlisted Member 5 Rep 48 Posts Drives: BMW 335i Join Date: Oct 2020 Location: USA iTrader: (0)	Help with gasoline smell but no leaks I started my 2008 e92 335i yesterday and after cutting the engine I noticed the smell of gasoline. I let it sit overnight and drove it again today. After coming back and letting it sit again for a few hours, I still noticed the smell. I traced the smell down to the drivers side of the engine bay. The passengers side does not smell like gasoline. I have seen no leaks last night or today in the garage…just the smell of gasoline. Any ideas?
	Appreciate 0 Tweet Quote

10-03-2021, 10:54 PM	#2
tcphoto Brigadier General 3557 Rep 3,061 Posts Drives: E92 335i 6MT Coupe Join Date: Dec 2009 Location: Nashville, TN iTrader: (1)	The fuel rail runs up the right/middle of the engine under the beauty cover, I would pull it and see if there’s a leak. __________________
	Appreciate 0 Quote

10-04-2021, 08:39 AM	#3
marvinstockman Major 400 Rep 1,080 Posts Drives: 2011 BMW 328i Join Date: Aug 2015 Location: Rockville, MD iTrader: (0)	Fuel injector not closing and leaking into engine.
	Appreciate 0 Quote

10-04-2021, 01:30 PM	#4
The843N54 Enlisted Member 5 Rep 48 Posts Drives: BMW 335i Join Date: Oct 2020 Location: USA iTrader: (0)	Thanks for the suggestions. I'll check both of those. Update* ran home at lunch and do not smell the gasoline odor anymore. I'll check again after work and update.
	Appreciate 0 Quote

10-04-2021, 02:38 PM	#5
RayLivingston Lieutenant 140 Rep 445 Posts Drives: '07 335i Sedan Join Date: Aug 2018 Location: California iTrader: (0)	Gasoline is highly volatile - it evaporates VERY rapidly, even at low temperature. A small leak will leak vapor, which is invisible, but will still have a strong odor, even from a VERY small leak. A larger leak can leak small quantities of liquid, which rapidly evaporate, leaving no visible trace. A much larger leak is required to actually drip enough liquid to persist for any length of time. If you smell gas, you HAVE a leak, whether you see it or not. You can buy a hydrocarbon "sniffer" to help localize the leak, but you're probably better off narrowing down the location as much as you can by sniffing, then just replacing ALL seals, gaskets, plastic parts and hoses in that general area that COULD possibly leak. In that absence of severe corrosion, there are not that many places the fuel system CAN leak, since the majority of the system is hard steel lines.
	Appreciate 0 Quote

10-04-2021, 05:15 PM	#6
IllSic_Design Colonel 2124 Rep 2,758 Posts Drives: 09 E92 335i Join Date: Jun 2016 Location: Northern California iTrader: (1)	Check out the fuel pressure regulator setup in the tank behind the drivers seat. Pop out the rear cushion and remove the cover panel and you'll see it. Common issue is the plastic cracking/breaking and spitting out fuel, mine just recently cracked and I need to replace it asap, decent fuel smell outside the car
	Appreciate 0 Quote

10-05-2021, 12:17 AM	#7
Serf27 Brigadier General 2856 Rep 4,324 Posts Drives: 335i Join Date: Apr 2018 Location: Sitting in a BMW. iTrader: (-1)	If the regulator is leaking, you’ll get a fuel smell and hardly see it leak.
	Appreciate 0 Quote