There are 21 owner-reported fuel system complaints for the 2003 Mercedes-Benz SL-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
The 2003 SL500 with seemingly no instigating incident or event had the gas tank baffle come apart due to the poor and faulty design of this component. This baffle now is loose and floats on the gas in the gas tank, banging around when there is acceleration or deceleration, even turning sometimes causes it to bang around. Speed bumps are another source of loud banging from the baffle bumping into the sides of the tank. The issue with 2003 SL500's is ubiquitous, it is not a question of what percentage of them will experience as it appears it will happen to this vehicle at some point due to the poor design and implementation of the baffle. This wouldn't be such a big problem if this was a minor repair and was a reasonable price to have a shop perform or for the more mechanically inclined owner to perform themselves, but it is a ridiculously complex and time-consuming job just to get to the gas tank and take it off. My mechanic told me it is akin to taking the transmission or engine out and as such labor is outstandingly and outrageously expensive with this job requiring approximately $2000-$2500 to perform according to my mechanic and other SL500 owners who have also had to deal with this issue. This is an issue that you may not experience if you don't own one of these vehicles for long enough, but the vehicle will have this problem during it's lifetime and Mercedes should be responsible for allowing such a design to make it into production.
HEARING CLANGING, THUMP NOISE BETWEEN SEATS AND TRUCK, TOOK IT TO A REPAIR SHOP AND WAS ADVISED IT IS A COMMON ISSUE WITH THIS MODEL - PROBLEM WITH BAFFLE IN THE TANK AND MIGHT HAVE COME OFF, SEARCHED ON-LINE AND FOUND HUNDREDS OF COMPLAINTS FOR THE SAME ISSUE, WAS THIS EVER ADDRESSED BY MB AND RECALLED?
HERE A BANGING NOISE BEHIND THE SEAT, TOOK IT TO A MERCEDES BENZ REPAIR SHOP. THEY INFORMED ME THE FUEL TANK BAFFLE IS BROKEN FREE. HE SAID IT IS VERY COMMON ON THIS MODEL. BUT NOT COVERED UNDER WARRANTY OR RECALL. IT WOULD CONT ME OVER 2,500.00 TO REPAIR. DOING SOME RESEARCH ONLINE AT MBWORLD FORUM. THIS HAPPEN ON ALMOST EVERY CAR LIKE THIS. I CAN NOT AFFORD TO FIX THIS. AND I AM WORRIED THIS MIGHT BLOW UP OR SOMETHING, SINCE SOMETHING BANGING AROUND THE THE INSIDE OF THE FUEL TANK CAN NOT BE SAFE, THIS CAR RUNS ON PREMIUM GASOLINE. IT SEEMS TO HAPPEN LOUDER WHEN THE TANK IS FROM 3/4 FULL TO 1/2. IF I LET IT RUN TO LOW THE FUEL GAUGE STICKS ON EMPTY UNTIL I GO OVER A BIG BUMP. I BELIEVE THIS IS A FACTORY DEFECT AS THE CAR ONLY HAS 60,000 MILES ON IT. I SHOULD NOT HAVE TO REPLACE THE FUEL TANK ON A CAR THAT COST ABOUT 100,000.00 NEW. BUT MORE IMPORTANT, I DO NOT FEEL THIS CAR IS SAFE TO DRIVE IN THIS CONDITION. THE DEALER STATED IT IS NOT A SAFETY ISSUE, JUST AN ANNOYANCE???
TL* THE CONTACT OWNS A 2003 MERCEDES BENZ SL500. WHILE DRIVING AT VARIOUS SPEEDS, AN ABNORMAL NOISE COULD BE HEARD IN THE VEHICLE. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHERE IT WAS DIAGNOSED THAT THE BAFFLE IN THE FUEL TAKE FRACTURED AND NEEDED TO BE REPLACED. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 56,408.
BAFFLE IN FUEL TANK STARTED HITTING THE SIDE OF THE TANK MAKE A NOISE WHEN FUEL TANK IS 3/4 FULL OR LESS. APPARENTLY THE BAFFLE BREAKS AT ONE END ALLOWING THE BAFFLE TO BANG AGAINST THE WALL OF THE FUEL CELL. *TR
I FILED THIS COMPLAINT MONTHS AGO AND HAVEN'T HEARD A WORD. THE ISSUE IS THE GAS TANK BAFFLE HAS APPARENTLY COME LOOSE FROM INSIDE THE TANK AND IS CREATING A BANG IN THE TANK VEHICLE IS SLOWING DOWN AND STOPPING. THERE WAS NO ACCIDENT. MERCEDES SAID THEY HAVEN'T HEARD OF THIS PROBLEM BUT IN RESEARCH THIS IS A PROBLEM WITH 2003-2004 SL500. IS THERE A SAFETY PROBLEM WITH THIS BAFFLE BEING LOOSE IN THE TANK? AND WHY ISN'T THERE A RECALL? *TR
I OWN A 2003 MERCEDES BENZ SL500. LIKE MOST OWNERS OF THIS VEHICLE, THE BAFFLE MOVES FREELY WITHIN THE GAS TANK WHICH CAUSES A NOISE AND IS POTENTIAL DANGEROUS IF A SPARK IS CREATED FROM THE BAFFLE HITTING THE INSIDE WALLS OF THE GAS TANK. FROM MY RESEARCH IT IS A MANUFACTURE ISSUE WITH THE WELDING OF THE BAFFLE TO THE INTERNAL WALL OF THE GAS TANK. THERE IS A TREMENDOUS AMOUNT OF COMPLAINTS AND THREADS ON MERCEDES FORUMS. PLEASE FOLLOW LINK TO SEE ALL COMPLAINTS. IT IS POOR CUSTOMER SERVICE AND ACCOUNTABILITY FROM MERCEDES BENZ USA TO NOT RECALL THE ISSUE. THERE IS OVER 20 PAGES OF COMPLAINTS REGARDING THIS ISSUE AT THIS LINK: HTTP://WWW.BENZWORLD.ORG/FORUMS/R230-SL-CLASS/1295215-SL500-NOISE-REAR-INTERIOR-WALL-GAS.HTML. *TR
BANGING NOISE INSIDE OF THE FUEL TANK. *TR
INTERNAL GAS TANK BAFFLE HAS COME LOOSE INSIDE THE GAS TANK. THIS CAUSES A CONSISTENT AND VERY ANNOYING RATTLING SOUND. *TR
TL* THE CONTACT OWNS A 2003 MERCEDES BENZ SL55 AMG. THE CONTACT STATED THAT WHILE DRIVING AT VARIOUS SPEEDS, HE COULD HEAR SOMETHING MOVING ABNORMALLY WITHIN THE FUEL TANK. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHERE THEY ADVISED HIM THAT HE NEEDED TO REPLACE THE FUEL TANK. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS CONTACTED AND OFFERED NO ASSISTANCE. THE FAILURE AND CURRENT MILEAGES WERE APPROXIMATELY 54,000.
THE BAFFLE INSIDE THE GAS TANK HAS COME LOOSE AND IS HITTING THE INSIDE OF THE TANK. THE ONLY TIME IT ISN'T NOISY IS WHEN THE TANK IS FULL. AFTER CONTACTING MERCEDES OF UTAH, THEY ADVISED THEY HAVEN'T HEARD OF THE PROBLEM. I DON'T KNOW IF THERE IS A SAFETY ISSUE WITH THE BAFFLE BEING LOOSE BUT IT IS A GREAT CONCERN TO ME. *TR
FUEL TANK BAFFLE FAILURE 2003 SL 500 MBZ. *TR
2003 SL500 MERCEDES BENZ. CONSUMER STATES NOISE INSIDE GAS TANK WHEN VEHICLE IS MOVING *TGW
I HAVE A 2003 SL500 MERCEDES . I HEAR EITHER A FREE DANGLING OBJECT BEHIND THE SEATS OR PERHAPS A NOISE FROM AN OBJECT IN THE GAS TANK (NOT SURE WHERE THE TANK IS). THIS CLANGING NOISE IS HEARD WHEN CAR IS SHOOK. EVEN A LIGHT NUDGE OF THE CAR WILL CAUSE IT TO CLANK. LIKE A DANGLING OBJECT, HARD ACCELERATION WILL CAUSE THE NOISE TO GO AWAY BUT WHEN THE CAR STOPS ACCELERATING A CLANGING NOISE IS HEARD. THE CAR IS RUNNING PERFECTLY. THIS MAY HAVE STARTED HAPPENING WHILE MY CAR WAS PARKED OVERNIGHT SEEING AS THOUGH IT WOULD HAVE BEEN HARD TO MISS IT WHEN PARKING THE NIGHT BEFORE. I CAN NOT RULE OUT VANDALISM OF SOME SORT BUT I AM HAVING A HARD TIME SEEING HOW THIS COULD BE THE CASE. MERCEDES DEALER STATES THAT THERE IS AN ANCHOR THAT HOLDS THE GAS TANK IN PLACE AND IT HAS BROKEN, THAT'S WHY THE I GET THE CLANGING NOISE!! STRIKING THE REAR WALL OF THE INTERIOR COMPARTMENT SEEMS TO MAKE A NOISE CONSISTENT WITH THE CLANGING. IS THIS SUPPOSE TO HAPPEN TO CAR OF THIS CALIBER? THE DEALER WANTS TO CHARGE $3000. *TR
MERCEDES-BENZ BUILT BAFFLES INSIDE THE FUEL TANK TO PREVENT FUEL SLOSHING NOISE DURING STOP AND GO MOTION. THESE BAFFLES WERE POORLY DESIGNED AND WEAKLY WELDED INTO PLACE RESULTING IN THEM COMING LOOSE AND BANGING AROUND INSIDE THE FUEL TANK. BEING A SMALL CONVERTIBLE AND GIVEN THAT FUEL TANK IS IMMEDIATELY BEHIND PASSENGER COMPARTMENT, END RESULT IS A VERY LOUD BANGING NOISE MAKING DRIVING A SLOW TORTURE. ASIDE FROM IRRITATING LOUD BANGING NOISE THERE IS ALSO A POTENTIAL OF EXPLOSION SINCE THIS IS A MOVING METAL PART INSIDE A METAL FUEL TANK CONTAINING GASOLINE AS BOTH LIQUID AND FUMES. THERE ARE ALSO MANY REPORTED INSTANCES OF THIS DESIGN FLAW WITH SOME DEALERS REPORTING 10 FUEL TANKS REPLACED IN 1 WEEK. PLEASE VISIT HTTP://WWW.BENZWORLD.ORG/FORUMS/R230-SL-CLASS/1295215-SL500-NOISE-REAR-INTERIOR-WALL-GAS.HTML AND HTTP://FORUMS.MERCEDESCLUB.ORG.UK/SHOWTHREAD.PHP?T=57846&PAGE=2 I BELIEVE THERE ARE ENOUGH OF THESE COMPLAINTS TO WARRANT A CLASS ACTION SUIT. BOTH MERCEDES DEALER AND MERCEDES CORPORATE (SUPERVISOR MR. MARIANO) HAVE REFUSED TO FIX THIS ISSUE INSISTING CAR IS OUT OF WARRANTY, AND THERE IS NO OPEN RECALL ON THIS ISSUE. DEALERSHIP QUOTED $2400 TO REPLACE FUEL TANK. *TR
DEFECTIVE FUEL TANK BAFFLES. FUEL TANK BAFFLE(S) COME LOOSE AND BOUNCE AROUND INSIDE TANK BANGING THE SIDES OF THE FUEL TANK. *TR
1. EVENTS LEADING UP TO FAILURE. DRIVER STARTED NOTICING "SLOSHING" SOUND COMING FROM GAS TANK AREA. NEXT DAY, A RATTLING NOISE STARTING COMING FROM GAS TANK AREA EACH TIME THE CAR WOULD COME TO A STOP. THE NOISE WAS CONSISTENT WITH SOMETHING FLOATING AROUND AND HITTING SOMETHING MENTAL INSIDE. THE SOUND COMES FROM THE GAS TANK AREA, CONSISTENT WITH A LOOSE PIECE OF METAL FLOATING IN THE GAS TANK. 2. UPON INSPECTION, THE BAFFLE WITHIN THE GAS TANK HAD BROKEN OFF AND WAS LOOSE, FLOATING IN THE GAS TANK. EACH TIME THE DRIVER COMES TO A STOP, THE BAFFLE WILL FLOAT AROUND AND BANG ON THE INSIDE OF THE GAS TANK. PRELIMINARY INSPECTION REVEALS THAT SUBSEQUENT MODEL YEAR GAS TANKS ARE DIFFERENTLY DESIGNED TO PREVENT SUCH FAILURE. CONSEQUENCES OF HAVING A LOOSE PIECE OF METAL FLOATING AROUND THE GAS TAKE ARE EXTREMELY SERIOUS. IF NOT TAKEN CARE OF PROMPTLY, THERE IS A POTENTIAL THAT THE METAL PIECE MAY DAMAGE THE GAS TANK AND CAUSE A FIRE OR OTHER HARM. 3. THE ENTIRE GAS TANK MUST BE REMOVED -- A $3000 PROCEDURE. BECAUSE OF THE NATURE OF THE DEFECT, MANY REPAIRS WILL FALL OUTSIDE OF THE WARRANTY PERIOD. THE DEALER PRETENDS AS THOUGH THIS IS AN UNCOMMON ISSUE. INDEPENDENT MERCEDES SHOPS CONFIRM THIS IS A WIDESPREAD ISSUE.
TL*THE CONTACT OWNS A 2003 MERCEDES BENZ SL500. WHILE DRIVING AT ANY SPEED, THE CONTACT HEARD A RATTLING NOISE COMING FROM THE TRUNK. HE TOOK THE VEHICLE TO THE DEALER AND WAS INFORMED THAT THE BAFFLES IN THE GAS TANK FAILED, WHICH CAUSED THE RATTLING IN THE GAS TANK. THE GAS TANK NEEDS TO BE REPLACED; HOWEVER, THE DEALER REFUSES TO TAKE RESPONSIBILITY FOR THE REPAIR. THROUGH ONLINE RESEARCH, THE CONTACT DISCOVERED NUMEROUS COMPLAINTS FOR THE SAME FAILURE. HE BELIEVES A RECALL SHOULD BE ISSUED. THE CURRENT AND FAILURE MILEAGES WERE 65,000.
NO INCIDENT. WAS DRIVING AND AS I PULLED INTO MY DRIVEWAY, HEARD BUMPING SOUND FROM CAR. ASKED MERCEDES WHAT IT WAS, THEY SAID LOOSE BAFFLE IN GAS TANK. SOUNDS LIKE MANUFACTURING DEFECT. CHECKED ONLINE AND FOUND MANY OTHERS WITH SAME PROBLEM. IT IS A COSTLY REPAIR JUST OUTSIDE OF WARRANTY PERIOD. *TR
2003 MERCEDES BENZ SL500 - BAFFLE BREAKS FREE WITHIN GAS TANK SEEMINGLY CAUSING A SAFETY HAZARD. MERCEDES DOES NOT REPLACE THE TANK FOR FREE IN ALL CASES. GAS TANK NEEDED REPLACED. *TR
Showing 1–20 of 21 complaints
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026