Which parts fail
Components named in complaints (power steering, steering column, rack and pinion).
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).
The contact owns a 1999 Mercedes-Benz ML320. The contact stated while driving approximately 30 MPH and other various speeds, the vehicle lost power steering functionality. The contact stated that she refilled the power steering reservoir several times and noted that there was a stain underneath her vehicle after parking overnight. The contact stated no warning light was illuminated. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle had not been diagnosed and had not been repaired. The manufacturer had been informed of the failure. The contact related the failure to a closed NHTSA Action Number: PE3006 (Steering). The failure mileage was approximately 220,000.
There was a recall on the steering on my 1999 Mercedes Benz . The Manufacturer said its closed . The steering is leaking and hard to drive and I fear the power steering pump will go out while I am driving the Vehicle. I fear for my safety. How can I get this recall opened and my vehicle fixed .
My wife drove from las vegas on 15 fwy back home when the engine light came on. About 10 minutes later, the vehicle pulled to the left so she steered to the right but it pulled to the left again. While the vehicle was pulling, she applied brakes to slow it down but it seem like the vehicle went faster and faster. She heard a sound "shhh" sound like a vacuum leaks. The steering wheel was pulling too hard to the left so she could not hold on anymore. The care then went off road and rolled over, landing in the section separating the cars going to las vegas and the cars going back. After landing she screamed how the baby, how the baby, he was 14 months, how every body--her daughters and parents...all 4 tires are SUV Michelin, just replaced about a month. We believe some things was wrong with the vehicle.
(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. …
Reference: vehicle complaint - 47046 in September 1999, we purchased a new Mercedes-Benz, ml-320. In 2003, the vehicle was part of a recall concerning a lower power steering hose and clamp at the radiator fitting. On August 7, 2007, while driving the vehicle, the lower power steering hose blew off losing all hydraulic fluid. We lost the power steering and had extreme difficulty steering the vehicle. The same problem has occurred with a family member's ml-320. In addition, the transmission has frozen four times in first gear. The Mercedes dealer was unable to locate the problem. The vehicle was towed to the dealer, and they replaced the hose; however, we have not retrieved the vehicle from the dealer because we are fearful about driving the vehicle due to these recurring problems.
In September 1999, we purchased a new Mercedes-Benz, ml-320. In 2003, the vehicle was a part of a recall for a lower power steering hose and clamp at the radiator fitting. On August 7, 2007, while driving the vehicle, the lower power steering hose blew off loosing all hydraulic fluid. We lost the power steering and had extreme difficulty steering the vehicle. The same problem has occurred with a family member's ml-320. In addition, the transmission has frozen four times in first gear. The Mercedes dealer was unable to locate the problem. The vehicle was towed to the dealer and they replaced the hose; however, we have not retrieved the vehicle from the dealer because we are fearful about driving the vehicle due to these recurring problems.
Continuing problems with power steering. Taken to the dealer for inquiry over 3 years ago; no resolution presented. Problems have persisted and gotten progressively worse. Only when researching, was I made aware of the recall. No notification from manufacture or dealer. Substantial costs incurred and vehicle continues to leak after numerous repairs. Moonroof unable to close 100% - taken to dealership. Advised the problem was seen routinely with this particular moonroof. Advised to fore-go repair due to cost. Upon extensive research, this problem is quite customary and unsure as to why the vehicle was not recalled or repairs made by the manufacturer. Would like a written response outlining options and resources to remedy these issues.
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.
Tl* the contact owns a 1999 Mercedes Benz ML320. The contact stated that while driving approximately 35 MPH, the power steering failed without warning. The vehicle was restarted but the failure persisted. The vehicle was taken to an independent mechanic where it was diagnosed that the power steering pump needed to be replaced. The vehicle was repaired twice, but the failure persisted. The manufacturer was notified of the failure. The approximate failure mileage was 99,000. Djr
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.
NHTSA investigations
Power steering hose assembly leakage
The hose clamp used to secure the power steering fluid cooling hose to the steering fluid cooler May not provide sufficient clamping force for the connection.the loss of power steering fluid May result in gradual reduction in power steering assist (I.e., increased steering effort) over time, with potential damage to the power steering pump.
Steering complaints in other ML320 years
Frequently asked questions
How common are steering problems on the 1999 Mercedes-Benz ML320?
NHTSA has 29 complaints about the steering of the 1999 Mercedes-Benz ML320, 23% of the model year's 125 complaints. The component named most often is hydraulic power assist › hose, piping, and connections (12 mentions).
Is there a recall for 1999 Mercedes-Benz ML320 steering problems?
No. NHTSA lists no steering 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 steering problems start?
Half of the complaints with a recorded mileage happened before about 64,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 7 injuries to steering 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.