Most common 1998 Mercedes-Benz ML320 problems
Share of the 133 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Mercedes-Benz ML320 complaints by model year
Best ML320 years: 2005, 2007, 2008. Years to avoid: 1998, 2000, 1999, 2001, 2002. Compare all years →
NHTSA defect investigations
Federal safety investigators have looked into a possible defect involving the 1998 Mercedes-Benz ML320:
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…
What 1998 Mercedes-Benz ML320 owners say
Engine & cooling all 32 →
Tl* the contact owns a 1998 Mercedes Benz ML320. The contact stated that the vehicle was being repaired by an independent mechanic for unrelated issues when she was informed that the ignition key needed to be replaced because it no longer functioned properly. The contact was not informed as to why the failure occurred. The key was not replaced. The manufacturer was made aware of the failure and the contact was informed that in order to remedy the failure, the vehicle would need an entire new ignition system. The vehicle was not repaired. The failure mileage was 180,000. The consumer discovered during research that merceds Benz installed an inadequate computer system in her vehicle. The system would only allow eight keys to be made for the lifetime of the vehicle. …
Laundry list of failures. Jack has almost killed me while changing tire. Vehicle fell, almost hitting me but catching side of vehicle before landing on me! Hood latch has failed on a few occasions, causing hood to open while vehicle was in motion. Air mass meter failed. Has required 5 (five!) alignments in two years. When brought to dealer's attention, was told nothing was wrong. A month later requires another alignment. Alignment problems causes wear on tires, which has caused hydroplaning and loss of control of vehicle. Vehicle swerves uncontrollably when hits anything other than flat road. Transfer case motor fixed by dealer without consulting. After repair, transfer case motor failed. Dealer states owner responsible for costs. Has had repair of harmonic balancer on front of engine due to excessive heat buildup leading to oil leak and failure of belt tensioner. …
Electrical system all 21 →
Tl* the contact owns a 1998 Mercedes Benz ML320. The contact stated that the vehicle was being repaired by an independent mechanic for unrelated issues when she was informed that the ignition key needed to be replaced because it no longer functioned properly. The contact was not informed as to why the failure occurred. The key was not replaced. The manufacturer was made aware of the failure and the contact was informed that in order to remedy the failure, the vehicle would need an entire new ignition system. The vehicle was not repaired. The failure mileage was 180,000. The consumer discovered during research that merceds Benz installed an inadequate computer system in her vehicle. The system would only allow eight keys to be made for the lifetime of the vehicle. …
Laundry list of failures. Jack has almost killed me while changing tire. Vehicle fell, almost hitting me but catching side of vehicle before landing on me! Hood latch has failed on a few occasions, causing hood to open while vehicle was in motion. Air mass meter failed. Has required 5 (five!) alignments in two years. When brought to dealer's attention, was told nothing was wrong. A month later requires another alignment. Alignment problems causes wear on tires, which has caused hydroplaning and loss of control of vehicle. Vehicle swerves uncontrollably when hits anything other than flat road. Transfer case motor fixed by dealer without consulting. After repair, transfer case motor failed. Dealer states owner responsible for costs. Has had repair of harmonic balancer on front of engine due to excessive heat buildup leading to oil leak and failure of belt tensioner. …
Fuel & propulsion system all 20 →
Laundry list of failures. Jack has almost killed me while changing tire. Vehicle fell, almost hitting me but catching side of vehicle before landing on me! Hood latch has failed on a few occasions, causing hood to open while vehicle was in motion. Air mass meter failed. Has required 5 (five!) alignments in two years. When brought to dealer's attention, was told nothing was wrong. A month later requires another alignment. Alignment problems causes wear on tires, which has caused hydroplaning and loss of control of vehicle. Vehicle swerves uncontrollably when hits anything other than flat road. Transfer case motor fixed by dealer without consulting. After repair, transfer case motor failed. Dealer states owner responsible for costs. Has had repair of harmonic balancer on front of engine due to excessive heat buildup leading to oil leak and failure of belt tensioner. …
My battery was low and unknown to me the ML320 for this year loses its transponder codes in the das security module when you try to start the vehicle with a low battery. This is evidentally the third key that has lost its programming on my vehicle due to low battery voltage. Cost so far is 499 for a key, weeks waiting for the key from Germany, and 300 to program it once they recieve the key. Its a dealership only item so its very very costly. This is a known problem with mercades and checking the forums it seems that everyone that has 1998-2000 model mercades all lose their transponder codes between 129,000 and 132,000 miles no matter what.this is an obvious manufacturers defect and a known issue that should be paid for by mercades. I never had these issues with my two 2002 ml500's but I will never purchase another Benz in my life.
1998 Mercedes-Benz ML320 engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 3.2L 6-cyl | 5-speed automatic | 4WD/AWD | 15 / 20 / 17 |
EPA ratings. Class: SUV.
Frequently asked questions
Is the 1998 Mercedes-Benz ML320 a good car?
Based on 133 owner complaints filed with NHTSA, the 1998 ML320 rates avoid: 4.5× as many complaints as a typical year of the ML320 at the same age. It is one of the ML320 years we suggest avoiding. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 1998 Mercedes-Benz ML320?
The engine & cooling — 32 complaints, 24% of all complaints for this model year, most often about engine. Next are the electrical system (21) and fuel & propulsion system (20).
How many recalls does the 1998 Mercedes-Benz ML320 have?
NHTSA lists no recalls for the 1998 Mercedes-Benz ML320. You can still confirm with your VIN using our VIN recall check.
What are the best and worst years of the Mercedes-Benz ML320?
The best years by complaints, compared at the same age, are 2005, 2007 and 2008. Years to avoid or approach with caution: 1998, 2000, 1999, 2001 and 2002. See the full Mercedes-Benz ML320 years comparison.
At what mileage do 1998 Mercedes-Benz ML320 problems happen?
The median mileage reported in complaints is about 79,000 miles; 19% of problems with a recorded mileage started before 50,000 miles.
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.