Case of the Month: Road Hazard

Aug 1, 2017 by

The insured said he “ran over something” in his Nissan Altima and then the engine blew up. There was smoke, but no fire. The last service was two months earlier for an oil change and a coolant flush. GEI was assigned to find out what really happened.

The vehicle was inspected at a body shop in Temecula. It was a 2006 model with 81,200 miles on it. Our expert observed a jagged hole in the side of the aluminum engine block and the engine components and the underside of the engine compartment were covered with a fresh, thin coating of oil.

He found light scratch marks on the left side of the protective shield located near the front of the vehicle. These marks could have been caused by contact with a concrete parking lot wheel stop or a similar object. The lower portion of the front bumper cover was in good condition with no evidence of contact with an object in the roadway. The undercarriage was also inspected and found to be free of any evidence that an object was driven over in the roadway that would cause engine damage or damage to any other component located underneath the vehicle.

The Altima was equipped with a 2.5 liter engine with the oil filter mounted on the passenger side of the engine. The oil filter was installed properly and no damage was found to the seal on the filter. The oil pan was inspected and also found to be free of any damage. No marks were found on the oil pan that would indicate contact with an object in the roadway.

The oil pan drain plug was installed properly and was properly tightened.

The vehicle sustained major damage to the engine when a connecting rod broke and knocked a hole in the engine block. This hole also allowed oil to escape and spray onto several engine components. 

The most likely cause of the damage was operating the vehicle with an insufficient amount of oil in the engine. No evidence was found on the undercarriage of the vehicle of external impacts that could have caused any damage to the oil pan or oil filter that would have allowed oil to escape the engine and cause the engine failure.

Our expert found one recall that pertained to vehicles with high or abnormal oil consumption. The records with Nissan indicated the recall was performed on this particular vehicle.

To summarize, the engine failure was caused by a broken connecting rod attached to the crankshaft and to a piston. In our expert’s experience, this kind of damage was most likely caused by operating the engine without a sufficient amount of engine oil. The resulting extreme friction in the rod bearing caused the bearing failure, which resulted in the connecting rod separation and engine failure.

No evidence was found that the driver “ran over something”.

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