I wanted to get some responses for the following situation:

I had my vehicle serviced on or about 16 March 2009 at a Mitsubishi Service Center in PA. At that time, it had approximately 101,000 miles with no major mechanical issues. I originally purchased the vehicle in the spring of 2004 and at that time, it had approximately 73,000 on it. Having driven the vehicle almost 30,000 miles with no mechanical issues, I felt it prudent to receive a timing belt and water pump replacement service just prior to embarking on a cross-country road trip to prevent any potential problems or damage to my vehicle. At approximately 103,000 miles, only 2,000 miles since receiving the timing belt service at Mitsubishi dealer, the check engine light illuminated on my dash. Not noticing any serious mechanical malfunctions at that time, I proceeded to drive to Arizona to avoid delaying a pre-planned road trip involving several family members.

I arrived in Arizona with approximately 106,500 (mid July 2009) on my vehicle, when I had the check engine code read with a scanner. The code read cylinder number five was misfiring. I checked under the hood to check the ignition cables and noticed one of the electrical connectors on the coil packs was not snapped into place. I snapped it into place and cleared the computer code, which resulted in no warning lights until the following month. In mid-August, the check engine light illuminated again indicating a random misfiring code. At this time, I also noticed a very consistent but unfamiliar metallic noise coming from the engine belt area. From my past 30,000 plus miles, I never heard this noise before. Not wanting to cause any further damage to the engine, I used an alternate vehicle for my transportation to Fort Benning, GA while on military orders for approximately two months.

I returned to Fort Huachuca, AZ late October 2009 and recovered the vehicle from storage. I drove the vehicle to a Mitsubishi service center in AZ to receive diagnoses and repair of the not forgotten engine trouble. At this time, the vehicle had approximately 107,500 miles (31 October 2009) only 6,000 miles (seven months) after the service performed at the dealer in Pennsylvania. I was informed by the certified Mitsubishi service center in AZ that the harmonic balancer was not functioning properly. I was also informed that the harmonic balancer maintains proper engine timing, lubrication, and crankshaft balancing to promote engine longevity and performance. I had the service center replace the harmonic balancer in hopes of rectifying the problem. Even after a new harmonic balancer was installed, the check engine light continued to illuminate indicating abnormal engine vibrations and improper cylinder firing.

At that point, the technician advised me that the improper function of the harmonic balancer over the previous extended period of time resulted in undue stress and vibrations that caused premature wear of the crankshaft bearings. The next step to fully repair my vehicle would require replacement of my entire engine block resulting in a very costly repair ($6,300).

Keeping in mind the original fault causing this sequence of events began at approximately 103,500 miles and the diagnoses was identified within MitsubishiÆs service warranty (12 Month, 12,000 miles) I feel this situation is not a coincidence. I would like to reiterate the 30,000 miles I drove with flawless engine performance and the fact that my engine has completely destroyed its bearings only 6,000 miles after service. Additionally, I would like to point out that the harmonic balancer must be removed in order to replace the timing belt.


Currently, the dealership takes no responsibility in this matter. I would like to get some professional responses to the following two questions:
Do harmonic balancers ever go bad with normal wear and tear or would improper function of a harmonic balancer be a result of improper removal/installation?
Hypothetically, if I were to purposely install a bad harmonic balancer on a perfectly good engine, how long would it take for the abnormal vibrations to wear out the crankshaft bearings? (1,000 miles, 5,000 miles, 10,000 miles, etc)
Mark