Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1999 Mercedes-Benz ML320 owners, lightly cleaned up (personal details are redacted by NHTSA).
I and my 7 year old daughter and her friend were entering my driveway on aug 14,2006, paused to open my garage door from the car and I was slowly moving in. All of a sudden car went out of my control in a flash that I did not even have time to react. It went and hit our other parked car in the garage with such a huge force that the second car literally went and tore the bedroom wall. Our second car is badly damaged on the front, back and one side (scraping a pole in garage) and wall needs fixing too. I truly suspect there is some mechanical problem for the sudden/unintended acceleration that LED to this unexpected behavior. So far we found the ignition got jammed (could not start and had to be towed in), other than the bumper/front damages. Car is still in the body shop for repairs, once finished it will be taken to the dealer for further analysis and check up.
1999 Mercedes-Benz ML320 SUV. On Thursday, December 19, my wife was driving the vehicle when suddenly the "harmonic balancer" failed (became detached), causing a complete loss of power to the vehicle, resulting in a disabled vehicle and leaving my wife and family stranded. The "harmonic balancer" is the main pulley wheel which is attached to the crankshaft. This pulley wheel in turn drives all other belt-driven items, such as power steering pump, ac, alternator, water pump, etc. First, this item should be so resilient that failure is nearly impossible, and second, both the tow truck driver and the dealer who is repairing it stated that this type of failure is "not at all surprising or uncommon" on the mb ML320 SUV. …
(1)vehicle was making a left hand turn and became almost impossible to turn steering wheel. (2) crankshaft dampener became separated at point of rubber vulcanized and caused serpentine belt to come loose leaving power steering to stop working along with all other pulleys run by the same belt. (3) dampener and belt were replaced. (old parts are available) this is an extremely dangerous situation that my local dealership says is happening very frequently. New types of replacement dampeners have been changed six (6) times in the last five (5) years in the parts book. Several local mechanics say it's a very common problem and they wonder why a recall has not been ordered. It would be very easy to find out how many crankshaft dampeners have been ordered and replaced by both dealers and parts sales. Again, let me say this is a very dangerous situation that is very common. …
Dt: the consumer stated that e oil filter housing failed. When the filter housing failed the oil sprayed all over the engine and the manifold. The oil had been changed on 7-30-2005. The oil filter on failed on August 1, 2005. The oil filter had been tightened and checked. The vehicle ran normally after the oil was changed and the vehicle was started. The owner changed the oil himself. The oil filter takes 8 ' quarts of oil. Consumer ha not taken the vehicle to the dealership. Instead, he purchased an oil filter,a plastic housing that holds the filter) and corrected the problem himself. Consumer talked to the dealership, and they said that the part was not covered by the warranty. Tconsumer ha not contacted the manufacturer. Consumer said that the oil filter design changed since the oil was changed last, and this new design was suppose to be an improvement.
Driving home from work the car's idle went to zero. This happened half-way home. Its a 30+ mile drive from work to home. Essentially the car just quit operating while merging on the interstate. Power steering was lost and this left my 8 month pregnant wife stranded in the middle of the merging lane to the interstate without the capability to restart the car. Successive tries to start the car failed. Only after 5 minutes the car was able to start and be pulled over to a safe place. Tried a 2nd time to drive it home and it left me stranded again without it being able to restart. Had to be towed on a flatbed tow truck home the remainder of the drive home.
Tl * - the contact received recall 03V121000. The contact took vehicle to mercedez Benz of palm beach January 3, 2007, and was denied arecall repair. The contact would like the repairs to be done under the recall. The contact stated that he received the same recall last year and chose not to address it at that time. The vehicle has had several failures , and was now being denied repair service. The cosumer took the vehicle to the dealer and they statedthere was nothing wrog with the vehicle. The consumer sated while driving, the the exhaust broke in half at the weld. Updated 01/22/07.
Consumer complained about having problems with the pulleys making a hole in the oil pan. Manufacturer was not notified at the time of this call. The vehicle had an oil leak. The technician stated the leak was caused by a pulley which was hitting against the oil pan. The technician stated that if the oil pan was replaced the pulley will still hit the oil pan and cause a leak. The check engine light illuminated. The dealer replaced the mass air flow sensor.
Tl* the contact owns a 1999 Mercedes Benz ML320. While the contact was driving approximately 35 MPH, the engine stalled with the illumination of the entire instrument panel. The engine failed to restart and the vehicle was towed to an authorized dealer who stated the failure was contributed to the crank shaft position sensor. The vehicle was repaired. The manufacturer was made aware of the problem. The approximate failure mileage was 72,000. Updated 10/31/11 updated 12/08/11
The harmonic balancer on my 1999 Mercedes ML320 engine type m112 failed and resulted in $4,000 to repair. The part failed with no advanced warning. Even the Mercedes dealership who performed the power steering recall two weeks prior to the failure did not spot any problem and they knew to be looking. I was lucky the failure occurred in my driveway backing out of the garage in stead of on the freeway with an immediate loss of power steering or destruction of the engine.
While driving a loud noise came from the front of the engine. I took the car to the dealer and the crankshft pulley has failed making a hole in the oil pan. The pulley and the oil pan were replaced and found out that this kind of premature failures has happened with this model. The dealer will not pick up the full cost for repairs since the car had 85000 miles. I think mb realizes that they have an issue with this type of failures but will not do a recall.
NHTSA investigations
Engine crankshaft pulley failure
The office of defects investigation (odi) opened this preliminary evaluation to investigate allegations of engine crankshaft pulley harmonic balancer failure that could result in loss of power-steering assist.odi has received a total of 546 non-duplicative reports that allege engine crankshaft pulley harmonic balancer failure on all Mercedes-Benz vehicles using the subject component.the subject component failures…
Engine complaints in other ML320 years
Frequently asked questions
How common are engine problems on the 1999 Mercedes-Benz ML320?
NHTSA has 35 complaints about the engine & cooling of the 1999 Mercedes-Benz ML320, 28% of the model year's 125 complaints. The component named most often is engine › gasoline › belts and associated pulleys (13 mentions).
Is there a recall for 1999 Mercedes-Benz ML320 engine problems?
No. NHTSA lists no engine & cooling recall for the 1999 Mercedes-Benz ML320. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1999 Mercedes-Benz ML320 engine problems start?
Half of the complaints with a recorded mileage happened before about 73,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.