2006 Mercedes-Benz R350 Problems

What owners report

Owners of this model year most often describe the rear air suspension sagging or the vehicle leaning to one side, frequently reappearing after parts were replaced. A second cluster of complaints is engine-related: a check-engine light and rough running traced to balance shaft and timing chain wear, typically appearing between roughly 50,000 and 100,000 miles. Smaller groups describe heated front seats overheating, rear tail/brake light failures, and coolant or cooling-system leaks.

1. 1
   Suspension

   Air suspension sags or vehicle leans to one side

   • 24 complaints (24%)
   • median 82,335 mi at 7.8 yrs old (24 state mileage)
   • filed 2012–2017

   Complaints describe the rear of the vehicle dropping overnight or the car sitting visibly higher on one side, sometimes with a red warning to stop because the vehicle is too low. Some owners report a warning light and a stiff, bouncy ride, and others say the car rose again after being parked or driven a short distance. According to the complaints, dealers replaced air springs, sensors, valves, the compressor or the control unit, and in several cases the same lean returned within days or weeks. Reported from roughly 45,000 to about 115,000 miles, most often in the 60,000-90,000 mile range and frequently noticed after the car sat parked.

   2 related service bulletins

   What to check: Park the car overnight and look at ride height on a level surface, then start it and watch whether it levels evenly; ask for records of air spring, compressor and valve block replacement. A pre-purchase inspection by a shop familiar with the air suspension is worthwhile.

   2 excerpts from owner complaints in NHTSA records

   “During driving my 2006 mb R350, warning light (check tire pressure) was on. And I pulled it over and found that the tires are fine but the vehicle leaned on the right side. I changed a suspension sensor at dealer, but it happened again one week later. I found that several other owners near me have same problem. I cannot understand why the maker have not recalled it.”

   NHTSA complaint #10533673, filed 2013-08, 86,650 miles

   “While on a road trip I started getting the red light that asked me to stop car to low. I stopped and it pumped up again. Drove a couple of miles and it did same thing. Took to mb dealer they said it was the suspension and charged me around 1200.00. 2 days later same problem it had not been fixed. I need to return and have them re-check. I heard negative feed back about this car from day 1.”

   NHTSA complaint #10548414, filed 2013-10, 84,000 miles
2. 2
   Engine

   Balance shaft wear, check-engine light and power loss

   • 28 complaints (28%)
   • median 79,000 mi at 5.9 yrs old (23 state mileage)
   • owner-quoted repair $6,000 (median of 8 quotes)
   • filed 2010–2022

   Owners describe the check-engine light coming on, often with rough running, vibration or reduced power, and diagnosis pointing to worn balance shaft sprocket and timing chain components. Complaints say the repair requires removing the engine and is expensive, and several owners mention a dealer acknowledging the pattern. Some report the light returned after magnets or other parts were replaced first. Most reports fall between roughly 40,000 and 105,000 miles, with several between 50,000 and 90,000 miles.

   2 related service bulletins

   What to check: Ask for service records showing whether balance shaft, sprocket and timing chain work was already done, and have a scan tool read stored engine codes. Listen for chain whine or rattle on a cold start.

   2 excerpts from owner complaints in NHTSA records

   “My engine warning light came on. I was told that the strut had gone bad and the cam in the engine went bad. I was told by the dealership that is normal in the 06 R350 and they are not sure why it hasn't been a recall. Im upset because im viewing your website and other sites that are design for other owners with the same vehicles and they are showing the same problems.. What will it take to get a recall on this before someone gets hurt.”

   NHTSA complaint #10452935, filed 2012-03, 51,000 miles

   “Check engine light came on, took the car to my mechanic that works on foreign cars, he informed me that my drive cam shaft is retarded basically stating that my sprockets that hold the timing belt are worn down, I am also loosing compression. I took it to the mercedes dealership and they told me they will goodwill the repair if that is really what is wrong with it. They however proceeded to tell me that your car has almost 100,000 miles on it, so it may just be the timing belt is worn down.(they will try anything to get out of the repair). …”

   NHTSA complaint #10450538, filed 2012-03, 92,261 miles
3. 3
   Seats

   Heated driver seat overheats or burns

   • 9 complaints (9%)
   • median 105,000 mi at 8.8 yrs old (8 state mileage, few)
   • 8 mention a crash, fire or injury
   • filed 2010–2019

   Complaints describe the driver's seat heater producing excessive heat, a burning smell or smoke, and in some cases burn marks or holes in the seat upholstery and clothing. Most say turning the heater off stopped it. According to the complaints, dealers replaced the seat and heating element in some cases and could not reproduce the problem in others. Reported across a wide range, from about 45,000 to 175,000 miles, usually shortly after the seat heater was switched on.

   What to check: Test the seat heaters on both front seats and watch for hot spots; check the seat back and cushion for burn marks or repairs to the upholstery.

   2 excerpts from owner complaints in NHTSA records

   “I started my 2006 Mercedes-Benz R350 and activated the driver seat warmer on high. After approximately 2.2 miles into my drive (speed 30-45 MPH) my seat felt very hot on my lower left side near my waist line. I reached back while driving to feel how hot the seat was and was surprised by a very hot sensation as though I had touched a hot needle. As I continued to drive and pull my body forward I noticed smoke rising from behind my left shoulder. …”

   NHTSA complaint #10502419, filed 2013-03, 45,317 miles

   “May 13, 2019, my wife started the car and drove for less than a mile when her dress started smoking from the driver seat that was alight. She stopped the car and removed our 11 month old baby from the backseat and called me. She has a video of the incident. I checked on mercedes USA site and found out that there was a class action law suite on this issue. We were not notified by either mb or the administrator of the case. This could have turned out deadly as the battery is under the passenger seat and the fuel lines. …”

   NHTSA complaint #11207461, filed 2019-05, 146,000 miles
4. 4
   Electrical system

   Rear tail and brake lights fail

   • 7 complaints (7%)
   • median 40,500 mi at 5.1 yrs old (6 state mileage, few)
   • filed 2010–2015

   Owners report tail, brake and reverse lights that stop working or work intermittently, with a dash warning about a backup light or bulb failure. Complaints mention repeated bulb replacement and diagnosis pointing to a worn contact or wiring in the rear light circuit. Estimates quoted ranged from a small rewiring job to replacing a control module. Mostly reported between about 33,000 and 90,000 miles.

   What to check: With the car parked, have someone operate the brakes, turn signals and reverse lights while you check the rear lamps and look for any bulb-failure messages on the dash.

   2 excerpts from owner complaints in NHTSA records

   “On my 2006 mercedes benz R350, the rear brakelights and taillights regularly fail to eliminate. The lights are very inconsistent and when they fail a back-up substitute light comes on. A message appears on the dash indicating that the substitute lights are on. After changing the bulbs numerous times, I was told by a mechanic at mercedes that the contact may be worn out.”

   NHTSA complaint #10372335, filed 2010-12, 65,000 miles

   “Rear light modules (tail, reverse, brake, signal) keeps on failing. Dealer quotes initially $250 to fix/rewire but then goes up to $950 to replace ecu. This is frustrating as this is driving hazard, owners are left without much choice. I have seen multiple complaints of the same issue so mb should already know that this problem exists and be honest upfront about it. I hope nobody gets hurt if the lights fail while driving this model/brand.”

   NHTSA complaint #10811954, filed 2015-12, 80,000 miles
5. 5
   Engine cooling

   Coolant leaks, low heat and overheating warnings

   • 6 complaints (6%)
   • median 92,105 mi at 8.1 yrs old (5 state mileage, few)
   • filed 2012–2015

   Complaints and bulletins describe coolant loss around the oil cooler area in the engine valley, weak heater output, and engine warning lamps with leak or camshaft-related fault codes. Owners report repairs for coolant leaks and related warning lights, sometimes repeated. Reports are spread from moderate to higher mileage, with most in the sample above 50,000 miles.

   6 related service bulletins

   What to check: Check the coolant level and look for dried coolant residue or oil traces in the engine valley, and confirm the heater blows warm air at idle. Ask whether the expansion reservoir or heater circuit has been serviced.

   2 excerpts from owner complaints in NHTSA records

   “The car rises up on one side when put thrust he computer no error code comes up . After a day or so sitting in the garage gets back to normal. Got it checked by mechanic no leaks . Then happened again they reset the computer charged me . Happened once again this time they changed the computer and the car showed airbag leaking. Car is out of warranty . Looked up on line mostly everyone who owns this car has this problem. This car has lot of issues. …”

   NHTSA complaint #10561838, filed 2014-01, 55,000 miles

   “The contact owns a 2006 mercedes benz R350. The contact stated that while reversing, the vehicle made an abnormal noise as the steering wheel seized and smoke started to emit from under the hood. The contact turned the engine off but the vehicle failed to restart. The vehicle was towed to an independent mechanic. The technician diagnosed that the power steering pump, serpentine belt and idler pulley needed to be replaced. The vehicle was repaired. However, the contact stated that the check engine light stayed on. …”

   NHTSA complaint #10746864, filed 2015-08, 130,000 miles

Buying note. These cars are old enough that condition and records matter more than mileage; budget for air suspension and engine-timing work unless there is documentation that both were already addressed. A thorough inspection and a scan-tool check before purchase are worth the cost.

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.