2004 Mercedes-Benz E500 Problems

What owners report

Owners of this model year most often describe a strong gasoline smell after refueling, traced by dealers and mechanics to the fuel tank, sending unit or pump seals under the rear seat; it typically fades as the level drops below about three-quarters full. A second recurring theme is the airmatic suspension letting the car down at one corner, often overnight or at start-up, with a 'stop, car too low' warning. A smaller but notable group describes loss of brake power assist tied to the Sensotronic Brake Control (SBC) unit.

1. 1
   Fuel system

   Fuel smell and leak after refueling (tank/sending unit)

   • 77 complaints (54%)
   • median 92,345 mi at 9.5 yrs old (68 state mileage)
   • 1 mention a crash, fire or injury
   • owner-quoted repair $968 (median of 9 quotes)
   • filed 2008–2026

   Complaints describe a strong gasoline odor inside the cabin and around the rear of the car, usually right after filling the tank and strongest until the level drops to roughly half or three-quarters. Several owners report seeing fuel pooling on top of the tank, dripping under the left rear of the vehicle, or collecting under the rear seat. Dealers and independent shops commonly replaced the fuel tank, sending unit, pump support or seals and gaskets; some owners say the odor returned until the tank itself was replaced. Reported from as low as about 9,000 miles up to 200,000, with most of the sampled complaints between roughly 45,000 and 140,000 miles, and the odor appearing after refueling.

   3 related service bulletins

   What to check: Fill the tank fully before buying and check for a fuel smell inside and around the left rear wheel, plus any staining or wetness on top of the tank under the rear seat cushion. Ask whether the tank, sending unit or pump seals have been replaced and keep receipts.

   2 excerpts from owner complaints in NHTSA records

   “I have a 2004 mercedes E500 and after filling the car with gas I began to notice the strong smell of gasoline coming from the vehicle after leaving it parked in my garage. As the vehicle was driven and the fuel fell below 1/2 tank the smell got less and less. However, I just filled the tank again the smell is stronger than before.”

   NHTSA complaint #10545557, filed 2013-09, 121,000 miles

   “I own 2004 mercedes E500 4matic one day after filling gas tank with fuel notice strong smell came from driver rear side of the car. I drove to my garage and investigate this problem. The sending fuel unit located under rear seat drivers side has a crack from which fuel leaking out. Called to mercedes benz of USA several times, but they refused fix this problem. This is the serious safety issue.”

   NHTSA complaint #10478227, filed 2012-10, 78,500 miles
2. 2
   Brakes

   Loss of brake power assist (SBC unit)

   • 27 complaints (19%)
   • median 99,000 mi at 11.3 yrs old (25 state mileage)
   • 2 mention a crash, fire or injury
   • filed 2004–2021

   Complaints describe a brake warning or 'reduced capacity' message appearing, followed by the pedal going to the floor or the car failing to stop with normal effort; in some accounts the pedal had to be pumped or the emergency brake used. Several owners had the car towed and were told the Sensotronic Brake Control hydraulic unit or pump needed replacement, with parts available only through a dealer. One complaint references a service bulletin covering the SBC service threshold. Reported from about 38,000 to 200,000 miles, at both low and highway speeds, with no warning before the assist dropped off.

   5 related service bulletins

   What to check: Ask for records of any SBC hydraulic unit replacement or extended-warranty work, and have a pre-purchase inspection read brake fault codes. Confirm that the brake warning light goes out after start-up and that pedal feel is firm.

   2 excerpts from owner complaints in NHTSA records

   “The cars brakes just quit without any warning which I was driving, as described below. This vehicle is equipped with sensotronic brake control that has a service threshold. When this threshold is reached the brake system defaults to non power assisted hydraulic mode to the front wheels only. This occurs without any prior warning and results in increased stopping distance. I have sent a copy of the mercedes service bulletin s142.46-p-0012a which addresses this issue. Mercedes stopped installing this system in 2006. …”

   NHTSA complaint #10691666, filed 2015-03, 97,000 miles

   “Benz2004 E500.original owner/55k miles.driving back from a long road trip, the service brake message came on.thinking it was just the pads, thought we could reach home.later, we realized what a dangerous thing we had done, by driving a car with sbc pump failure.we could have taken off a bridge or thrown into a swamp or put someone else in danger.this problem cannot be fixed at any auto shop, it has to be towed to the dealer, from wherever you are stuck and only dealer can fix it.dealer said mfr, will not assist in repair because it is past …”

   NHTSA complaint #10676289, filed 2015-01, 54,000 miles
3. 3
   Suspension

   Airmatic suspension drops at one corner

   • 19 complaints (13%)
   • median 98,500 mi at 9.3 yrs old (17 state mileage)
   • filed 2007–2018

   Owners describe the car sitting noticeably low at one corner, often in the morning or after being parked, sometimes with a loud pop as air escapes. The instrument cluster shows a 'stop, car too low' or 'visit workshop' message, and the raise button does not correct it. Complaints mention repeated failures at different corners, a front strut air bladder letting go, and shops replacing air struts, valve blocks or the airmatic compressor; owners note the repair is expensive, especially at a dealer. Mostly reported between roughly 65,000 and 150,000 miles, frequently after the car sits overnight or when starting it in the morning, and sometimes while driving.

   6 related service bulletins

   What to check: Start the car from cold and watch the ride height at all four corners, then let it sit and check again; listen for hissing or a compressor that runs long. Ask whether struts, valve block or compressor have been replaced.

   2 excerpts from owner complaints in NHTSA records

   “While d irving home from work, after stopping for light, when light changed and I proceeded to make a right turn, I suddenly couldn't hardly turn. It took all I had to make turns, then after arriving home my husband noticed the suspension had dropped on the vehicles and was resting on the left rear tire. Power steering resoviour was empty and when he put some in. It all ran on the ground. V echo lie was in motion.”

   NHTSA complaint #10864238, filed 2016-05, 76,933 miles

   “Takata recall my mercedes benz E500 back air shocks stopped lifting the car when I started it in the morning and the red indicator light want go off unless I stop it will lift up an then goes back down.”

   NHTSA complaint #11103451, filed 2018-06, 175,000 miles
4. 4
   Fuel system

   Fuel gauge reading does not match tank level

   Mentioned in 4 of 60 sampled complaints

   Complaints describe the fuel gauge sticking or showing a level that does not match how much fuel is in the tank, sometimes reading half full when empty. In some accounts the car was slow to start or stalled after refueling, and shops replaced both sending units and their seals. A service bulletin attributes this kind of mismatch to the fuel level sensor circuit, including wiring connectors, the rear signal module or the instrument cluster. Reported across a wide mileage range, from about 38,000 to 180,000 miles, typically noticed at or after refueling.

   1 related service bulletin

   What to check: Compare the gauge reading with a known fill amount and watch it over a few days of driving. Ask whether the sending units or fuel level sensor circuit have been serviced.

   2 excerpts from owner complaints in NHTSA records

   “Vehicle has a recall on replacement of fuel tank. Mercedes benz dealer did not want to honor the recall. When I fill car up with gas it leaks out of the tank and on the ground. Mercedes-benz dealer said I missed the time for the recall. I went to the dealership before the recall ended in 2019 spoke with the service advisor at the mckinney Mercedes-Benz dealership and I informed him the car was not drivable due to the braking system failure call the spc hydraulic pump. …”

   NHTSA complaint #11408466, filed 2021-04, 141,111 miles

   “Engine stopped while running the car. Had to have a local repair shop replace both sending units and seals/gaskets. I believe this is a recall already but I paid for it?”

   NHTSA complaint #11209995, filed 2019-05, 74,587 miles

Buying note. Have any candidate car inspected for fuel leaks around the tank and sending units and for airmatic ride height at all four corners, since these are the most frequently reported items. Ask for service records on the SBC brake unit and confirm recall work on the sunroof panel has been completed.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.