RoadVitals

2008 Mercedes-Benz S550 Problems

Owner-reported complaints filed with NHTSA, grouped by component

Data refreshed

Owner complaintsComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
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Latest May 7, 2025
Components namedHow many of our component categories appear on at least one report for this model year. One report can name several.
11
Crash or fire reportedComplaints whose submitter recorded that a crash or a fire occurred. These are the reporter's own answers on the NHTSA form, not verified findings.
1

What this page shows

Everything below is an owner-reported complaint submitted to NHTSA about the 2008 Mercedes-Benz S550, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.

Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.

Reports by component

Ranked by how many owner reports name each component category

  • Electrical416.7%
  • Tires & wheels416.7%
  • Fuel system312.5%
  • Other / unspecified312.5%
  • Powertrain (other)28.3%
  • Engine28.3%
  • Suspension28.3%
  • Driver assistance14.2%
  • Seat belts14.2%
  • Airbags14.2%
  • Brakes14.2%

Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.

Each component in detail

What the reports in each category say, in the owners' own words

Electrical

Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.

4
reports

From owner reports, verbatim

The contact owns a 2008 Mercedes-Benz S550. The contact stated while driving 40-50 MPH, the vehicle was shuddering intermittently. The contact stated that the failure recurred while at a complete stop. The check engine warning light was illuminated. The contact stated that the failure had been recurring intermittently. The vehicle was taken to an independent mechanic, where it was diagnosed that the wiring harness was causing an engine misfire. The mechanic related the failure to an unknown recall. The dealer was notified of the failure. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 40,000.

NHTSA ID 11577423 · filed Mar 14, 2024

The contact owns a 2008 Mercedes-Benz S550. The contact stated while driving 35-40 MPH, the message "SAFETY" was temporarily displayed on the instrument panel. Additionally, the contact stated while starting the vehicle on several occasions, the message " SAFETY " was displayed on the infotainment system screen. The check engine warning light was illuminated, and the messages "Active Head Lamp Inoperative" and "Service Required. Do Not Shift Gears" were displayed. The contact also stated that upon shifting into drive (D), the gear shift indicator displayed that the transmission was in park (P). The contact stated that the vehicle failed to shift into the intended gear and had become undrivable. An independent mechanic replaced the battery; however, the failure persisted. The mechanic informed the contact that the computer needed to be reset. The vehicle was not repaired. The used car dealer was notified of the failure. The Mercedes-Benz dealer and manufacturer were not notified of the failure. The failure mileage was approximately 176,310.

NHTSA ID 11541256 · filed Aug 28, 2023

Too few reports in this category for a page of its own — they appear in the full complaint list.

Tires & wheels

Reports naming tires, wheels, hubs, or the tire-pressure monitoring system.

4
reports

From owner reports, verbatim

We were traveling home and our TPMS indicated a tire failure. The PSI starting dropping rapidly. We took the tire off and found that only 4 " of rubber holding the back sidewall together on the tire. I then inspected the other tires on the car (which were purchased and installed at the same time) are showing signs of failure as well. All of the tires are 255-40-r19 We had a family of 4 in the vehicle at the time of the incident.

NHTSA ID 11547224 · filed Sep 28, 2023

I PURCHASED 4 NEW 255/45/ZR18 EXTREMECONTACT DWS ABOUT 13 MONTHS AGO AND NOW ALL 4 TIRES HAVE A BULGING BUBBLE ON THE SIDEWALLS. OF COURSE I BROUGHT IT BACK FROM WHERE I PURCHASED IT FROM AND THEY BLAME IT ON POT HOLES, ROAD HAZARDS. I CURRENTLY CANNOT DRIVE THE VEHICLE IN FEAR THAT I MIGHT HAVE A BLOW OUT. I HAVE PURCHASED MANY TIRES BEFORE THAT WERE NOT CONTINENTAL AND NEVER EXPERIENCED WHAT IM GOING THROUGH NOW. LET SEE HOW LONG IT WILL TAKE TO BE CONTACTED WITH SOME HELP OR WHAT EXCUSE THEY GOING TO COME UP WITH. *TR

NHTSA ID 10705489 · filed Apr 13, 2015

Too few reports in this category for a page of its own — they appear in the full complaint list.

Fuel system

Reports naming fuel storage or delivery — tanks, pumps, lines, injectors and fuel leaks.

3
reports

From owner reports, verbatim

MY VEHICLE HAS A STRONG GAS ODOR WHILE DRIVING BUT PARTICULARLY WHEN THE VEHICLE IS STATIC OR PARKED. THIS SMELL IS SO STRONG THAT I CANNOT SIT IN THE CAR AND MY CLOTHES REAK OF THE SMELL. THERE HAS NOT BEEN ANY EXTERNAL GAS LEAKAGE OR PERFORMANCE ISSUES WITH THE CAR. ONLY THE GAS ORDOR THAT HAS GIVEN ME A HEADACHE AND MAKES ME NAUSEATED. THE CAR ONLY HAS 70,000 MILES ON IT.

NHTSA ID 11164448 · filed Jan 2, 2019

TL* THE CONTACT OWNS A 2008 MERCEDES BENZ S550. THE CONTACT STATED THAT THE VEHICLE HAD EXPERIENCED AN ABNORMAL FUEL ODOR. THE VEHICLE WAS TAKEN TO THE DEALER WHERE IT WAS DIAGNOSED THAT THE FUEL TANK WAS FRACTURED AND NEEDED TO BE REPLACED. THE VEHICLE WAS NOT REPAIRED DUE TO THE PART BEING ON BACK ORDER. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE CONTACT HAD REFERENCED NHTSA CAMPAIGN: 12V557000(FUEL SYSTEM, GASOLINE) AS A POSSIBLE SOLUTION TO THE FAILURE HOWEVER THE VIN WAS NOT INCLUDED. THE FAILURE MILEAGE WAS APPROXIMATELY 91,000.

NHTSA ID 10956010 · filed Feb 21, 2017

Too few reports in this category for a page of its own — they appear in the full complaint list.

Other / unspecified

Reports whose component NHTSA recorded as unknown, or that do not map to one of the categories above.

3
reports

From owner reports, verbatim

EVEN CHANGE TO NEW TIRES, THE AIR PRESSURE UP TO 37 AND ALWAYS AFTER 1 WEEK OR SO, DOWN TO 33, COMPLAIN AND CHANGE TIRE AND STILL HAVE THE SAME RESULT. YOU COULD ONLY CHECK THE TIRE PRESSURE AFTER YOU RUN FOR A WHILE. MASSAGE CHAIR, AFTER OPERATION AND ALL THE SUDDEN IT STOP. CLOCK IN THE CABIN DOESN'T CHANGE EVEN YOU SET IT UP AND THE INTERNAL SAID THE RIGHT TIME AND THE FRONT DOESN'T CHANGE

NHTSA ID 11292448 · filed Jan 1, 2020

I WAS IN UNFAMILIAR AREA. REMOTE KEY WOULD NOT OPERATE. WHEN USING SMALL KEY TO ENTER VEHICLE CAR SIREN WOULD NOT QUIT BLARING AND .NEW BATTERIES DID NOT HELP. MERCEDES RESPONDER TOLD ME I HAD INOPERATIVE "DEAD" KEY. CAR OF COURSE WAS INOPERATIVE. NO WAY TO MOVE CAR FROM AREA. COULD NOT SECURE CAR. I HAD RBM IN ATLANTA ON CELL PHONE ENTIRE TIME. ABOUT HOUR LATER SOMEONE TOOK ME TO MY HOME FOR SPARE KEY. THIS WORKED. KEY WAS AS MERCEDES RESPONDER TOLD ME...... DEAD. THE MERCEDES KEYS ARE UNSAFE AND UNDEPENDABLE. NEED TO BE RECALLED. MERCEDES WOULD NOT REPLACE "DEAD" KEY PER KYRUS FRAMES AT RBM IN ATLANTA. BECAUSE MY CAR HAD 57000 MILES ON IT AND OUT OF WARRANTY. KEY MUST BE RECALLED DUE TO SAFETY CONCERN THERE IS NO WAY TO OPERATE A "DEAD" KEY. MERCEDES RESPONDER TOLD ME THAT HE SEES IT ALL THE TIME. WHAT IF??? I HAD BEEN MILES FROM HOME? UNSAFE AREA? COMPROMISING SITUATION?THIS IS UNACCEPTABLE FOR $100,000 CAR. I COULD BE DEAD. JUST PROVIDE A WORKABLE KEY MERCEDES. *TR

NHTSA ID 10536999 · filed Aug 23, 2013

Too few reports in this category for a page of its own — they appear in the full complaint list.

Powertrain (other)

Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.

2
reports

From owner reports, verbatim

The contact owns a 2008 Mercedes-Benz S550. The contact stated while driving 35-40 MPH, the message "SAFETY" was temporarily displayed on the instrument panel. Additionally, the contact stated while starting the vehicle on several occasions, the message " SAFETY " was displayed on the infotainment system screen. The check engine warning light was illuminated, and the messages "Active Head Lamp Inoperative" and "Service Required. Do Not Shift Gears" were displayed. The contact also stated that upon shifting into drive (D), the gear shift indicator displayed that the transmission was in park (P). The contact stated that the vehicle failed to shift into the intended gear and had become undrivable. An independent mechanic replaced the battery; however, the failure persisted. The mechanic informed the contact that the computer needed to be reset. The vehicle was not repaired. The used car dealer was notified of the failure. The Mercedes-Benz dealer and manufacturer were not notified of the failure. The failure mileage was approximately 176,310.

NHTSA ID 11541256 · filed Aug 28, 2023

MERCEDES BENZ, S550, 4MATIC, 2008. I WAS STOPPED AT A RED LIGHT. WHEN THE LIGHT TURNED GREEN AND I WAS MOVING FORWARD AT ABOUT 15-20 MILES PER HOUR, THE CAR CAME TO A SUDDEN STOP. THE VEHICLE BEHIND ME ALMOST RAN INTO MY BACK SINCE THERE WERE NO BRAKE LIGHTS ILLUMINATED WHEN THIS UNFORTUNATE MALFUNCTION TOOK PLACE. I IMMEDIATELY LOOKED THE CONTROL PANEL FOR ANY MALFUNCTION ALARM AND THERE WERE NONE. THE ROOT CAUSE OF THE PROBLEM WAS FRONT DIFFERENTIAL SEIZE UP WITHOUT ANY WARNING. THERE WERE THE RIGHT AMOUNT OF OIL IN THE RESERVOIR SO THE PROBLEM WAS NO DUE TO LACK OF LUBRICATION. THE CAR WAS REPAIRED BY MB DEALER AND I WAS GIVEN A BILL FOR (HOLD ON TO YOUR PANTS) $8,252. I CALLED MB CUSTOMER SERVICE TO FIND OUT IF THERE ARE ANY RECALL ON THIS MALFUNCTION. I WAS TOLD NONE REPORTED. I HAVE A HARD TIME BELIEVING THAT I AM THE ONLY ONE WITH THIS PROBLEM. I ALMOST CAME TO A DECISION TO SIGN OVER THE TITLE AND HAVE THEM SELL THE CAR TO RECOVER THE REPAIR COST. OBVIOUSLY THE DEALER IS NOT AT FAULT HERE. HOWEVER YOU WOULD EXPECT THAT A CAR OF THIS CALIBER WOULD BE BETTER DESIGNED AND SUPPORTED. AS YOU HAVE GUESSED I AM UNHAPPY WITH MY MB. BY THE WAY IF YOU ARE TRYING TO SIGN ON FOR MB ONLINE OWNER COMMUNITY AND WANT TO CHOOSE THE USERNAME "UNHAPPY", YOU CAN'T. IT IS ALREADY TAKEN. TRY IT WITH SOME #S. *TR

NHTSA ID 10502393 · filed Mar 11, 2013

Too few reports in this category for a page of its own — they appear in the full complaint list.

Engine

Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.

2
reports

From owner reports, verbatim

I’m reporting a serious safety issue with the balance shaft sprocket in my Mercedes-Benz S550 (M273 engine, 273.968). This is a known defect that causes the sprocket to wear out far too early due to poor material design. When it wears, it throws off the engine timing, leading to check engine lights, rough idling, reduced power, and even stalling. In some cases, the engine can shut down while driving, which is a major safety risk. Thousands of people have experienced this exact problem, and it’s all over Mercedes forums, Reddit, and technical bulletins. Mercedes quietly updated the part in later models, which shows they knew the early ones were defective. Some people got repairs under warranty or “goodwill,” but most of us are stuck with thousands in repair bills for something that clearly shouldn’t have failed. This isn’t just a mechanical issue—it’s a safety concern. Imagine merging onto a highway or turning through an intersection when the engine loses power. That’s a real risk with this defect. Mercedes should be held accountable, and NHTSA needs to investigate and push for a recall before someone gets hurt or worse.

NHTSA ID 11659570 · filed May 7, 2025

The contact owns a 2008 Mercedes-Benz S550. The contact stated while driving 40-50 MPH, the vehicle was shuddering intermittently. The contact stated that the failure recurred while at a complete stop. The check engine warning light was illuminated. The contact stated that the failure had been recurring intermittently. The vehicle was taken to an independent mechanic, where it was diagnosed that the wiring harness was causing an engine misfire. The mechanic related the failure to an unknown recall. The dealer was notified of the failure. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 40,000.

NHTSA ID 11577423 · filed Mar 14, 2024

Too few reports in this category for a page of its own — they appear in the full complaint list.

Suspension

Reports naming suspension components — springs, struts, shocks, control arms and related hardware.

2
reports

From owner reports, verbatim

I HAD TO REPLACE BOTH FRONT AIR SHOCKS AROUND 90,000 MILES. NO OFF ROAD DRIVING. BOTH AIR STRUTS LEAKED WITHIN 4 MONTHS . SUSPENSION WARNING LIGHT CANE ON FIRST. THEN A MESSAGE TO STOP THE CAR AND NOT OPERATE.

NHTSA ID 11124439 · filed Sep 4, 2018

TL* THE CONTACT OWNS A 2008 MERCEDES BENZ S550. THE CONTACT STATED THAT THE FRONT END OF THE VEHICLE LOWERED, INDICATING THAT THERE WAS SUSPENSION FAILURE. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 70,000. UPDATED 09/01/15*LJ UPDATED 12/7/2015*JS

NHTSA ID 10730608 · filed Jun 26, 2015

Too few reports in this category for a page of its own — they appear in the full complaint list.

Driver assistance

Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.

1
report

From owner reports, verbatim

P-RC-200808004 BODY CONTROL ACCELERATION SENSORS...MODELS 2001-2008 11/4/2008 - 200807001 RE-CODE THE SOFTWARE CALIBRATION NUMBER (SCN) 11/04/2008 - 200803005 REPLACE FRONT SAM S-SC-2012070002 RETROFIT ADAPTER WIRING HARNESS ON CAMSHAFT ADUSTMENT SOLENOIDS MODELS 2005-2011 S-RC-200807001 REVISION TO STEP Z, IN WORK PROCEDURE RECODE THE SOFTWARE CALIBRATION NUMBER (SCN). *TR

NHTSA ID 11324288 · filed May 12, 2020

Too few reports in this category for a page of its own — they appear in the full complaint list.

Seat belts

Reports naming seat belts, buckles, retractors and pretensioners.

1
report

From owner reports, verbatim

TL* THE CONTACT OWNS A 2008 MERCEDES-BENZ S550. THE CONTACT STATED THAT WHILE STOPPED, THE VEHICLE WAS SUDDENLY REAR-ENDED CAUSING THE VEHICLE'S DRIVER AND PASSENGER FRONT SEAT HEAD REST AIR BAGS TO DEPLOY. THE CONTACT STATED THAT HE SUSTAINED BROKEN BONES IN HIS NECK AS WELL AS INJURIES TO HIS LEFT ELBOW AND BACK AREA. THE FRONT PASSENGER RECEIVED INJURIES TO HIS NECK AND BACK AREA AND WAS TRANSPORTED THE HOSPITAL BY AMBULANCE WHILE THE DRIVER DROVE HIS VEHICLE TO THE HOSPITAL. A POLICE REPORT WAS FILED. THE VEHICLE WAS TAKEN TO A LOCAL A BODY SHOP POST INCIDENT WHO REPAIRED THE BUMPER AMONGST OTHER PARTS OF THE REAR OF THE VEHICLE. THE VEHICLE WAS THEN TOWED TO THE DEALER (MERCEDES-BENZ OF WAPPINGERS FALLS (134 OLD POST RD, WAPPINGERS FALLS, NY 12590 PHONE: (845) 298-0600) WHO PERFORMED THE HEAD REST AIR BAGS REPLACEMENT, AS WELL AS, ELECTRICAL AND OTHER REPAIRS DUE TO THE COLLISION. THE MANUFACTURER WAS MADE AWARE AND OPENED A CASE REGARDING THE MATTER. THE CONTACT WAS CONCERNED WITH THE FORCE OF THE HEAD REST AIR BAGS DEPLOYMENT. THE APPROXIMATE FAILURE MILEAGE WAS 78,013. *DR*JB

NHTSA ID 11329607 · filed Jun 18, 2020

Too few reports in this category for a page of its own — they appear in the full complaint list.

Airbags

Reports naming the air-bag system — deployment behaviour, inflators, sensors and warning lights.

1
report

From owner reports, verbatim

TL* THE CONTACT OWNS A 2008 MERCEDES-BENZ S550. THE CONTACT STATED THAT WHILE STOPPED, THE VEHICLE WAS SUDDENLY REAR-ENDED CAUSING THE VEHICLE'S DRIVER AND PASSENGER FRONT SEAT HEAD REST AIR BAGS TO DEPLOY. THE CONTACT STATED THAT HE SUSTAINED BROKEN BONES IN HIS NECK AS WELL AS INJURIES TO HIS LEFT ELBOW AND BACK AREA. THE FRONT PASSENGER RECEIVED INJURIES TO HIS NECK AND BACK AREA AND WAS TRANSPORTED THE HOSPITAL BY AMBULANCE WHILE THE DRIVER DROVE HIS VEHICLE TO THE HOSPITAL. A POLICE REPORT WAS FILED. THE VEHICLE WAS TAKEN TO A LOCAL A BODY SHOP POST INCIDENT WHO REPAIRED THE BUMPER AMONGST OTHER PARTS OF THE REAR OF THE VEHICLE. THE VEHICLE WAS THEN TOWED TO THE DEALER (MERCEDES-BENZ OF WAPPINGERS FALLS (134 OLD POST RD, WAPPINGERS FALLS, NY 12590 PHONE: (845) 298-0600) WHO PERFORMED THE HEAD REST AIR BAGS REPLACEMENT, AS WELL AS, ELECTRICAL AND OTHER REPAIRS DUE TO THE COLLISION. THE MANUFACTURER WAS MADE AWARE AND OPENED A CASE REGARDING THE MATTER. THE CONTACT WAS CONCERNED WITH THE FORCE OF THE HEAD REST AIR BAGS DEPLOYMENT. THE APPROXIMATE FAILURE MILEAGE WAS 78,013. *DR*JB

NHTSA ID 11329607 · filed Jun 18, 2020

Too few reports in this category for a page of its own — they appear in the full complaint list.

Brakes

Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.

1
report

From owner reports, verbatim

I HAVE 2008 MERCEDES S550. THE CAR SUDDENLY STARTED MAKING NOISE IN THE FRONT AND I CALLED DEALERSHIP. THEY TOLD ME THE BRAKES ARE GONE AND EVEN ROTORS ARE DAMAGED. I HAD NO INDICATION ALL THIS TIME I WAS DRIVING THAT THE CAR HAD NO BRAKES AS NO BRAKELIGHTS CAME ON. TILL THE TIME I WENT TO DEALERSHIP NO INDICATION CAME AS SENSORS ARE NOT WORKING. IS IT NOT UNSAFE TO BE DRIVING ON THE HIGHWAY 60 TO 70 MILES /HR WITH NO BREAK SENSORS . I CALLED MERC AND THE TOP TWO PEOPLE ROBYN AND TIM IN ESCALATION DEPT TELL ME AT FIRST THEY ARE PICKING UP THE. REPAIR AND THEN TOTALLY TURNED THEIR BACKS AND YEARS AND SAID TO ME IT IS NOT A SAFETY ISSUE WHERE THE CARS BREAKS ARE COMPLETELY GONE TO THE POINT THE ROTORS ARE DAMAGED AND THERE IS MO INDICATION. WITH A 100K CAR WHICH HAS ALL THESE FANCY FEATURES BUT BRAKES ARE NOT IMO. *TR

NHTSA ID 10255933 · filed Jan 21, 2009

Too few reports in this category for a page of its own — they appear in the full complaint list.

Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.

Elsewhere on this vehicle

Data sources

Data on this page last refreshed .