2008 Mercedes-Benz ML350 Problems

What owners report

Owners of this model year most often describe power steering problems: fluid leaks, hard or unresponsive steering, and failed racks or pumps, frequently at moderate mileage. A second common theme is water entering through the rear tail lamp seals and damaging modules under the spare tire, which owners link to power liftgate, lighting and brake light faults. Brake light socket failures, seat heater overheating and a brake booster recall also appear in the complaints.

1. 1
   Steering

   Power steering fluid leak and loss of assist

   • 20 complaints (30%)
   • median 54,000 mi at 6.1 yrs old (17 state mileage)
   • filed 2009–2022

   Complaints describe steering that becomes hard to turn, especially at low speed or right after start-up, often accompanied by a whining, moaning or squealing noise. Owners report power steering fluid loss and dealers or shops diagnosing a leaking steering rack, a failed high-pressure line, a reseal job or a pump replacement. Some report the repair was done more than once, and several note that their vehicle was not covered by a steering recall. Mostly reported between roughly 20,000 and 110,000 miles, with a number of cases in the 50,000-90,000 mile range.

   1 related service bulletin

   What to check: Check the power steering fluid level and look for leaks or dampness around the rack, lines and pump, and listen for whining while turning the wheel cold. Ask for service records showing any rack, line or pump work.

   2 excerpts from owner complaints in NHTSA records

   “We took the 2008 mercedes benz ml 350 in to a local mb dealer for a schedule a service and transmission flush and asked that an oil leak on the front driver's side axel be inspected. We were told that the vehicle needed the steering rack input shaft valve assembly replaced. We called a local shop to get a second quote for the work and were told that they wouldn't quote us or touch it because of a recall on the model and year -- NHTSA campaign id# 08v682000. …”

   NHTSA complaint #10428806, filed 2011-10, 54,000 miles

   “I had the car serviced by the dealer and asked that they specifically check for any leaks or other abnormalities as I would be out of the 50,000 warranty period. About three weeks later I noticed an oil drop on the floor of my garage. I took the car to the dealer and they said that the seals in the steering were the cause of the leak and needed to be replaced. I argued with them about paying for this repair as the car only had 53000 +_ and this should not fail unless it was a defect design. …”

   NHTSA complaint #10452085, filed 2012-03, 53,000 miles
2. 2
   Electrical system

   Water leak through tail lamp seals damages rear modules

   • 7 complaints (10%)
   • median 105,000 mi at 7.7 yrs old (7 state mileage, few)
   • filed 2015–2018

   Owners describe water pooling in the spare tire well after rain, traced to the rear tail lamp assembly seals. Complaints link this to a power liftgate that stops working or runs but does not move, flashing or blinking lights and instrument panel warnings, and modules that were replaced. Several owners say the seal was replaced but the problem returned. Mostly reported above roughly 70,000 miles, often after several years of use in wet conditions.

   What to check: Lift the spare tire cover and check for moisture, rust or water lines in the well, and inspect the tail lamp seals. Test the power liftgate through several open and close cycles.

   2 excerpts from owner complaints in NHTSA records

   “Due to a faulty right taillamp seal, water got into a control module and damaged it beyond repair. I woke up and walked outside to see my headlights flashing and upon further inspection my key fob not working, srs disabled, and many other miscellaneous electronic components disabled. Some time before this, the motor to the rear hatch stopped working, possibly for the same reason.”

   NHTSA complaint #11115405, filed 2018-08, 110,000 miles

   “2008 mercedes ml 350 brake lights continue to send an error message that left and right brake lights are out sometimes they are and sometimes they aren't its isn't the light bulb and was told this is a common issue with this year. Water continues to leak in through the rear brake light damaging the sam unit”

   NHTSA complaint #11118762, filed 2018-08, 95,000 miles
3. 3
   Exterior lighting

   Brake lights out from burnt sockets and wiring

   • 10 complaints (15%)
   • median 86,500 mi at 7.4 yrs old (8 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 2011–2019

   Complaints describe rear brake lights going out, sometimes both at once, with warnings on the dash and bulbs that are not the cause. Dealers reportedly replaced sockets and wiring with an updated kit, and owners note the same repair pattern on other models. Some complaints tie the socket failure to water getting into the rear light housing. Spread from roughly 43,000 to 101,000 miles in the sampled complaints.

   What to check: Have someone press the brake pedal while you check both rear lamps, and look at the bulb sockets for scorching or corrosion. Ask whether the socket or wiring kit has been replaced.

   2 excerpts from owner complaints in NHTSA records

   “My ML350 kept blowing it's brake lights. After awhile of this I realized that something was obviously wrong. At this point both lights were out at the same time. I took it in to find that the sockets were burnt out and needed to be replaced. I was then told that the wiring also needed to be replaced and mercedes benz had a fix for it all but at a price. I was also told that the c series had a recall for the same problem. Why are there no recall for the ml or the m series?”

   NHTSA complaint #10703825, filed 2015-04, 101,250 miles

   “Rear brake lights went out within short period of each other. Checked with dealer, wanted to replace whole light assembly. Checked online, turns out to be faulty wiring/install for which mb actually has a repair kit. Seems to be quite a frequent problem. In fact the mb c class was recently recalled for that same reason, why not the ML350???”

   NHTSA complaint #10653782, filed 2014-11, 43,600 miles
4. 4
   Electrical system

   Seat heater overheating and burning

   • 5 complaints (7%)
   • median 112,000 mi at 6.1 yrs old (3 state mileage, few)
   • 4 mention a crash, fire or injury
   • filed 2011–2020

   Owners describe the heated front seats becoming extremely hot, with smoke or a burning smell and burn marks or holes in the seat cushion. In one case a burning odor came from under the passenger seat and flames followed. Complaints note the absence of a shut-off for the heater. Reported from about 41,000 miles upward, including vehicles with well over 100,000 miles.

   What to check: Turn the seat heaters on briefly and check the seat cushions for scorch marks, discoloration or repaired leather, and stop using the heater if it gets unusually hot.

   2 excerpts from owner complaints in NHTSA records

   “After starting up the car and turning on the seat heaters we noticed a strong burning smell. We had just entered a slip road and my wife (who was driving) felt a burning in her lower left side. Next thing... She was on fire! Her winter coat bust into flames and after pulling over I grabbed her out of the drivers seat and rolled her in the snow to extinguish the fire, we were amazed that the seat had a large burn hole through the leather and that there wasn't any safety shut off for the seat heater initiated by the vehicle. …”

   NHTSA complaint #11310224, filed 2020-02, 167,000 miles

   “As I was pulling out of my driveway, my seat heater burned a hole through my seat, my shirt, and my pants. I saw a small flame and felt a burning on my back and immediately turned off the seat heater.”

   NHTSA complaint #10428906, filed 2011-10
5. 5
   Brakes

   Brake booster recall with parts unavailable

   Mentioned in 4 of 60 sampled complaints

   Complaints describe owners being told their vehicle was included in a brake booster recall but that the replacement part was not available, leaving the vehicle waiting at the dealer for extended periods. These owners had not experienced a brake failure themselves; the complaints center on the delay in completing the recall. Filed mostly in 2022, generally with no mileage given.

   Recall 22V315000 · DO NOT DRIVERecall 24V298000 · DO NOT DRIVE

   What to check: Ask the seller or dealer to confirm whether recalls 22V315000 and 24V298000 were completed, and get documentation before purchase. Pay attention to brake pedal feel and any softness or reduced assist.

   2 excerpts from owner complaints in NHTSA records

   “The contact owns a 2008 Mercedes-Benz ML350. The contact received notification of NHTSA Campaign Number: 22V315000 (Service Brakes, Hydraulic) however, the part to do the recall repair was not yet available. The dealer was made aware of the issue. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact had not experienced a failure. Parts distribution disconnect.”

   NHTSA complaint #11472787, filed 2022-07

   “The contact owns a 2008 Mercedes-Benz ML350. The contact received notification of NHTSA Campaign Number: 22V315000 (Service Brakes, Hydraulic) however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.”

   NHTSA complaint #11483473, filed 2022-09

Buying note. Have a pre-purchase inspection focus on the steering system for leaks, noise and assist, and on the rear cargo area for water intrusion. Ask for recall paperwork on the brake booster campaigns and for records of any lighting or liftgate module repairs.

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.