Mitsubishi Lancer Evolution 9 High wear of thrust bearing in the crankshaft case study 

Affected Component: Petrol engine
Industry Sector: Motorsport
Machine: Mitsubishi Lancer Evolution 9
Critical Report: High wear of thrust bearing in the crankshaft


Typically, when the term “oil analysis” is used people tend to relate it to expensive large-scale mining and civil operations. A recent success story proves this is not the case and “oil analysis” can have many benefits for a huge variety of applications.

An example of the potential benefits comes from a rally car team based in NSW running a Mitsubishi EVO 9 rally car in the NSW rally championship.

As a competitive motorsport racer competing in a rally car series, the customer was committed to keeping their prized Mitsubishi Lancer Evolution 9 in top condition. This included regular oil sampling of the petrol engine straight after each race event, so that any work required could be completed before the next race.

The customer purchased 10 oil sampling kits (part number KOWA-OILNZCM) online at my.komatsu.nz. The kits were delivered to the customer within days which also included the sample tubes and return mail bags.

Test Results

To help determine the amount of any potential wear or contamination, the oil samples were processed through ICP analysis and Particle Quantifier (PQ). The first 4 samples were taken which returned acceptable levels of iron Results are below
  • 3,973 km – 13 ppm (parts per million) of iron
  • 4,325 km – 7 ppm of iron
  • 5,395 km – 9 ppm of iron
  • 5,768 km – 11 ppm of iron
    However, the 5th oil sample returned increased levels in iron, copper and lead compared to previous test results and so was given the alert status of “Caution”:
  • 6,093 km – 78 ppm of iron, 13 ppm of copper (previously 1 ppm), 8 ppm of lead (previously 1ppm)
    The 6th engine oil sample returned elevated levels of iron and PQ base on trend:
  • 6,383 km – 251 ppm of iron


Early detection of wear, avoiding costly engine failure

The laboratory results detected abnormally high levels of iron and PQ indicating component wear from the engine. The customer was contacted soon after the completion of the test report.

Komatsu CMS recommended the customer to further investigate so that the root cause could be identified. The first step was to cut open the oil filter in which the customer saw pieces of metal (debris build up).

The customer immediately carried out further inspections on the engine to find the thrust bearing from the crankshaft wearing. As a result, it had caused damage to the crankshaft itself. Had this fault gone undetected and unchecked, a complete and costly engine failure would have occurred.   

Luckily, the next race was 4 weeks away. This allowed their mechanic to replace the crankshaft and thrust bearing in time, so that they could complete in the next race. At the completion of the replacement, another oil sample was taken which returned to normal levels.

Finding abnormality based on trends

Komatsu CMS recommends regular oil sampling to detect early signs of component wear and to avoid engine failure. Given that this rally car was expected to be utilised at full capacity, the customer’s early decision to regularly sample the engine oil has saved the owner thousands of dollars.

Furthermore, consistently undertaking oil samples allowed Komatsu CMS to identify abnormalities and provide expert recommendation based on historical test data. The customer was able to avoid a costly engine failure, allowing them to continue to chase another NSW rally championship win.