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.

A quick oil change-with the wrong oil

The insured took his late model sports car to the local branch of a nationally recognized company for an engine oil and filter change. Three months later he brought it in again for another engine oil and filter change.   They used a premium synthetic oil both times.   Two weeks later, the engine failed.   GEI was called in to investigate the cause of the engine failure.

The vehicle was examined at a high performance auto repair shop.  The engine had been removed prior to the expert’s arrival, and was disassembled.

The camshaft bearing surfaces in both cylinder heads exhibited severe wear damage. Severe wear damage was also observed on the mating camshaft bearing caps.   A section at the rear of one of the bearing caps broke off.

The journals on the left and right camshafts exhibited transferred aluminum from the cylinder head bearing surfaces.   Evidence of overheating was also observed at these locations.

The front end of the right camshaft exhibited circumferential scratches, which indicated that the camshaft sprocket had rotated on the camshaft.   Damage was also observed in the slot for the camshaft sprocket alignment key. The corresponding slot in the right camshaft sprocket had been sheared away.

No significant damage was observed on the engine block.   The crankshaft exhibited wear damage on the journal for the number six connecting rod.   The number six connecting rod and its bearing inserts also exhibited excessive wear and heat damage.   A significant amount of aluminum debris was found in the crankshaft oil passages when the engine was disassembled.

The oil pump was partially disassembled for the inspection.   Removal of the oil pump cover revealed that the inner rotor of the gerotor pump was broken.   (Call us if you need the definition of a gerotor pump!)

The damage to the camshafts and camshaft bearing surfaces was caused by insufficient lubrication.   The engine oil level was at its proper level prior to the engine failure, and it was not contaminated.   The owner had specified a premium synthetic oil, which he had received.   So why the lubrication failure?

The answer was found in the viscosity of the oil that was used.   The higher the viscosity number, the thicker the fluid is.   A low number of 5 to 20 indicates a fluid that flows easily at low temperatures-much like water.   A high number like 50 indicates a thicker fluid that flows slowly at low temperatures-much like honey or molasses.   The engine was an overhead cam design, which positions the camshafts on top of the cylinder heads relatively far from the oil pump.   The manufacturer specified a low viscosity 5W-20 motor oil for this engine, in part to ensure that the camshafts received oil from the oil pump shortly after startup.

On both oil changes, the oil change technicians used much higher viscosity motor oil.   The higher viscosity motor oil in the insured’s engine took a longer time to reach the camshaft bearing surfaces.   As a result, the camshafts did not receive adequate lubrication during the first few moments after the engine was started.   Over multiple engine start cycles, this condition caused excessive wear of the camshaft bearing surfaces.

As these surfaces deteriorated, friction between the camshafts and the bearing surfaces increased.   Eventually, the heat created by this friction caused the right camshaft to seize.   As the camshaft suddenly stopped rotating, the timing chain continued to turn the camshaft sprocket.   As a result, the camshaft alignment key slot was sheared out of the sprocket.

The deteriorating camshaft bearing surfaces also caused small pieces of aluminum wear debris to enter the lubrication system.   Some of this debris clogged the oil passages in the crankshaft, which restricted oil flow to the connecting rod bearings and caused the number six connecting rod bearing to fail.   Debris contamination caused the oil pump to fail as well.

Whether through ignorance or carelessness, by refilling the engine with an incorrect, heavier viscosity motor oil, on two separate occasions, the technicians directly contributed to the engine failure