1998 Mercedes-Benz ML320 Engine Problems

Which parts fail

• Engine
  7
• Engine › Gasoline › Belts and associated pulleys
  7
• Exhaust system › Emission control › Catalytic convertor
  6
• Engine › Gasoline
  4
• Cooling system
  2
• Exhaust system
  1

Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).

Mileage when the problem started

• Under 25k
  00%
• 25k–50k
  422%
• 50k–75k
  317%
• 75k–100k
  633%
• 100k–150k
  422%
• 150k+
  16%

Owner reports

Selected complaints filed with NHTSA by 1998 Mercedes-Benz ML320 owners, lightly cleaned up (personal details are redacted by NHTSA).

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. …

Our 1998 Mercedes m320 has been subject to unexpected stalling for some time. More recently this has increased in frequency and we have periods of loss (reduction) of power while driving. The dealer advises that we have deterioration of the catalytic converters and that there has been a recall for this problem on newer models of the m class - but not our year. We have the car at the dealer waiting for replacement parts. We are told it will be a number of weeks since the parts are in great demand. Repairs will cost over $2,000 - but the car is clearly unsafe. Most frequent stalls are starting at a light or stop sign. One concern is knowing this problem with model years just newer than ours are subject to recall while our year isn't. …

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.

Harmonic balance pulley was failed and was recalled 1998 Mercedes ML320 -[redacted]. Mercedes refused to pay total labor for process. Vehicle has no equipment other than Mercedes made and installed equipment. Vehicle has Mercedes fog light bar on front (standard Mercedes made and installed items). If the part had not been defective, this charge would not have occurred. Regardless of the fact that is was installed by Mercedes before I got the car--I do not feel that I should be burgeoned with Mercedes costs due to poor quality of defective parts. Updated 07/19/2012

98 Mercedes ML320 with 75,000 miles harmonic balancer went up and destroyed half of the engine which cost over $5,000 in repairs. Mbusa said they had no previous complaints and that I was responsible for all repairs since it was out of warranty. I have since found out that this is a known problem for these vehicles/engines that mb is trying to cover up.

Harmonic balancer broke apart at 140K , no indication of failure, just lots of smoke and no steering capabilities, was in the middle of the intersection. Police pushed me to safety. Plastic shattered everywhere in engine compartment.. The defect was the plastic pully, internet research showed other people had same problem and cost them thousands.

Belt tensioner failed at 73886 mile,$308.00. Harmonic balancer failed @80,772 miles. Lost power steering and all accessories. Replaced belt ,oil pan ,tensioner(again),harmonic balancer,oil ,oil seal. Mercedes paid for parts. I paid for labor $675.00. Did tensioner fail first time because of balancer. Was balancer a known defect?

Regarding NHTSA action number pe03058. The crankshaft pulley harmonic balancer was found to be defective on my Mercedes ml, 320 today. The vehicle had 57,435 miles. The dealer told me it was starting to fail and recommended it be replaced or it could lead to a loss of power steering and major engine damage.

While driving in traffic, the vehicle seems to be leaking exhaust directly into the passenger compartment causing me to have severe headaches and feel very tired. It helps somewhat with the odor when the HVAC is switched to recirculate, but I feel that co is still seeping in the vehicle.

NHTSA investigations

Engine complaints in other ML320 years