A Kia Engine Failure

The insured’s son was driving the family’s Kia when the engine quit running and would not restart. It was then towed to the dealership. The mechanics at the dealership said that one of the pistons melted and a connecting rod had broken. The insured said that there was a “fire” internally in the engine and the claim should be paid as a fire loss, not denied as an engine failure.


GEI was brought in to determine the cause of the engine damage. Was the “internal fire” the cause of the engine damage, or did something else cause the engine damage?

After researching recalls and related issues (none were found), our expert inspected the vehicle with its newly-installed replacement engine at the Kia dealership. While the vehicle’s original engine was replaced before the inspection, it was still available for examination, and showed no external signs of damage.



Some of the broken internal parts that were saved were retrieved from the engine’s oil pan when it was removed. As part of the replacement of the engine process, the dealership also had drained the fuel tank and discovered that the fuel was contaminated. A photograph of the contaminated fuel was supplied to our expert, but, unfortunately, after they photographed the sample, they discarded all of the contaminated fuel.



With no physical fuel sample to test, a laboratory analysis of the contaminated fuel was not possible.

Our expert examined the broken connecting rod and piston fragments. Their failure was the result of operating the vehicle with contaminated oil caused by a leaking fuel injector.



The leak at the fuel injector was the result of the contaminated fuel causing a deterioration of the fuel injector seal. The seal caused the injector to stick in the open position and allowed an abnormally large amount of fuel to enter the combustion chamber. This excess fuel was not burnt, but instead, washed the piston rings of their coating of oil. This allowed the fuel to then drip into the engine crankcase and mix with the engine oil.


This mixing or dilution caused the oil to become extremely thin and lose its lubricating properties. This resulted in excessive wear to the connecting rod bearings.



The abnormal wear caused an out-of-tolerance clearance between the connecting rod bearing and the crankshaft. As the engine continued to run, the gap continued to increase, and the out-of-tolerance clearance between the rod and the bearing caused an out-of-balance connecting rod, which finally broke, causing damage to the piston. At this point in the timeline, the engine no longer operated.

The first possible cause of contaminated fuel would be from a purchase of fuel at a refueling station. This seemed unlikely since the photograph of the contaminated fuel appeared orange in color. Most, if not all, automotive fuels including methanol and diesel are colorless. Another possibility was vandalism. Since a fuel sample was not retained for laboratory analysis, the chemical or chemicals that caused the fuel injector seal failure is unknown. Regardless of the source of the fuel contamination, it was the cause of the engine failure.

In conclusion, no evidence was found that would indicate that the engine damage was caused by anything other than the operation of the engine with contaminated fuel, which wore out the injector seals, diluted the engine oil, caused bearing failure, and ultimately, destroyed the engine.


Expert of the Month: Tom Wright

Mr. Wright has more than thirty-five years in the automotive field, with hands-on knowledge and experience in the operation and repair of all major systems. He owned and operated his own independent automobile repair facility for many years. Mr. Wright’s expertise includes the ability to inspect, analyze, document and determine the cause of vehicle failures, including the analysis of engines, transmissions, brake systems, steering and suspension components, and body damages. He has completed courses in automotive fire investigations for cause and origin determinations. He is also a Bosch Certified Event Data Recorder Technician.