A month ago I accidently left my car running idle all day while I was at work. The car now smells like fuel. Any idea where I should start looking or what the issue may be? I would like to take care of issue myself instead of taking it to a shop.

 

rent an 'ozone generator' from a tool rental business, google how to deodorize a car with one. pay particular attention to the cautions, as even very dilute ozone is highly irritating.

basically, you'll run the ventilation fan in recirc mode, put the ozone generator in the cab of the car, run an extension cord to it, and plug it in for like 4 hours with all the doors and windows closed. then unplug it, and wait at least 4 hours, open up the vehicle and let it air out for several more hours.

the ozone gas (O3 instead of normal oxygen O2), will tear apart most all organic volatiles that make stinks, like baby barf, mold smells, fuel/oil smells, etc.

 

While you try to fix your gas leak, do keep a fire extinguisher handy (30yrs ago I had a fire near my carburator, it's a helpless scene!)

Everything in the fuel system is fair game: from tank covers at the rear, to line couplers, injectors seals up front...

Try to corner your leak by locating the source of smell. That is faster than removing too many parts without result.
I'd concentrate on what got really hot: engine bay or near exhaust lines.
🤞

 

Might be a good idea to pull the rear seat bottom and see if you have a leak at the top of the fuel pump or fuel filter housings?

 

 

I removed the rear seat and saw this on the driver side. What do you guys think it is? What should I replace?

 

Gas leak due to a crack on the pump housing. Did you check the passenger side as well? Just in case.

Are you planning to DIY? Here are some videos to get an idea of the work. If you feel confident working with a fuel tank open, it is not a difficult task, but you must be careful.
the list of parts may include gaskets, send and fuel pump units, new harness.

 

that is indeed the fuel pump and sending unit access in the gas tank, and it certainly looks like its been leaking. next step is to take it out and clean it up and inspect the seals and gaskets. in your picture there are what /look/ like cracks between about 9:30 and 11:30 near the rim of the plastic plate. but they could just be dirt, can't really tell. and it certainly looks like there's leakage around two connectors and the main seal around the outside appears to be quite swollen and damaged at 3 oclock.

(I am assuming these cars have an 'in tank' fuel pump, but I don't actually know... my old benzes all had the fuel pump(s) under the car, and the tank was behind the back seat of the sedans, or under the trunk around the spare tire in the wagons]

 

I'm going to inspect it this weekend. Anyone know of a good place to order these parts?

 

A bit more details if your vehicle, say VIN ? Or year, model, etc?

 

2010 e350

 

take it apart, clean the bad parts up, and bring them to your local Mercedes dealer's parts counter along with your VIN.

 

if you post the VIN here, someone like me with access to the factory parts catalogs could look the assemblies up for you, but until you take it apart, its only going to be guesswork as to whats actually needed.

 

Post your VIN, and take LCG offer to show the parts numbers, and prepare a budget for the worst case scenario.

Once open , because of age, minimum gaskets. The harness is submerged in fuel, i.e. replace no questions. Ring may crack when removing it because of age or approach removing it. Then, check for where the crack is

 

VIN WDDHF5GB0AA080956
2010 E350

 

ok, here's the whole page from the parts catalog, I'll leave it to you ot puzzle out what you have, as I'm not familiar with that end of these cars yet. ignore the E550 in the filename, that was me, ERROR - INSUFFICIENT COFFEE

 

On my W211 before I sold it, the fuel pump was leaking, I was able to refer to the MB Fuel Pump Replacement Warranty to the dealer, it was replaced at no cost to me.

https://www.carcomplaints.com/news/2...gas-tank.shtml

 

Anyone know where I can purchase the Fuel Filter Unit(221-470-17-90)? According to the Mercedes Parts Website this product is discontinued.

 

new aftermarket part on fleabay, https://www.ebay.com/itm/143656020933 ... ooops, out of stock.

ok, here's someone in Lithuania on Amazon marketplace,

 

=== Updated ===
I have attached your vehicle's datacard. If you read it carefully, you will notice code 917, i.e. PZEV EMISSION USA.

When looking for fuel system parts, check it says that is for PZEV system explicitly; otherwise, you may end up with the wrong part.

Here are a few links to PZEV parts that seem to fit your vehicle (I have never bought from them, but some in the forum have)

https://www.autohausaz.com/pn/2214700390OE

https://www.autohausaz.com/pn/CV-2044700794

https://www.autohausaz.com/pn/A2C53345695Z

https://www.autohausaz.com/pn/MB-2114710179

https://www.autohausaz.com/pn/MB-2044700438

 

huh. Mercedes parts says that PN A2214700390 is for a CL 550, 216.371, and was superceded by the part used in the OPs' E550 ...

30 A 221 470 03 90
* FUEL FILTER UNIT
FUEL TANK
Code: M273/M273+(494/918);
Replaced by: A 221 470 13 90
Replaced by: A 221 470 17 90


so yes, it may well work.

 

Covered by emission warranty if located in CA, MA, ME, NY, CT, RI, PA, NJ, OR, WA or VT.

 

the PN A 221 470 17 90 is indeed for option code 917 PZEV(*). that other part I linked as an alternative is *NOT* PZEV

and AFAIK, those emission warrantees expired, its 2021, and the car is MY 2010



(*) - anyone else think Partial Zero is a contradiction ?

 

15 years/150,000 miles expires 2025

 

FCPEURO has been my go-to for decades, I also use AutohausAZ regularly and so far no disappointments. I also use ECS Tuning but mostly for Schwaben tools like their oil extractor and trim removal tools. There is also a Benz dealer that sells online, they are located in California, I think it's mercedesbenzparts.com and their usually 20-25% less than my local four dealers.

I hope you're in one of those eleven states with 10 years/150k miles, I'm in one of the 39 with 8 years/80K mile warranty