The brakes don’t work!

In freeway traffic, the insured was approaching a vehicle that was slowing in front of her, she reportedly applied the brakes but the vehicle would not stop! You can guess what happened next. Yes, a call to her insurance company.


Rollover damage from the accident.

Garrett Forensics was assigned to inspect and photograph the insured’s 2015 Jeep Grand Cherokee, and complete the following:
• Determine if a manufacturing defect, pre-incident mechanical failure, service error, or wear-and-tear issue in the brake or throttle systems caused or contributed to the date-of-loss incident.
• Identify an open manufacturing recall issue which could have caused or contributed to the date-of-loss incident.
• Download the Event Data Recorder (EDR) with the Crash Data Retrieval (CDR) tool to determine if a fault within the brake and/or throttle system could have caused the date-of-loss incident.

An inspection was performed of the front and rear brake systems including the pads, rotors, calipers, ABS sensors and cables and all other components. The brakes were found in good, safe operating condition. No visible brake fluid leaks were detected in the brake fluid lines or components. No skid mark indicators were located on the front tire treads indicating that the vehicle’s ABS was operating properly prior to and during the date-of-loss impact.

Next, the electronic throttle pedal and its mechanism was inspected and found to be in good, safe condition and operated properly. No problems here.

Sometimes, having extra floor mats can have an effect on catching the throttle pedal but its positioning showed that the extra mat did not interfere in this case.

Only one open recall was found for the vehicle from the National Highway Traffic Safety Administration but it was for a cruise control problem not related to this incident. So what did malfunction?

So next in the investigation came the Event Data Recorder (EDR) download and the truth came to light. The EDR shows the vehicle performance information up to 5 seconds before the impact occurs. Information like engine rpm, throttle percentage, vehicle speed, brake activation, and ABS activation, this information can be very telling during the investigation.

The CDR download of the EDR module recorded that the brake system was not activated during the 5 seconds prior to airbag deployment. The throttle pedal was fully engaged for the first 3 of the recorded 5 seconds. The pedal was then quickly released and sharply re-engaged to fully (100%) open at approximately 1 second prior to the airbag deployment. This recorded data indicated a possible pedal identification error during, at least, the last five-seconds prior to the rollover.

Extra aftermarket floor mat.

The insured thought she was stepping on the brake pedal but in reality she was stepping on the accelerator pedal! A very high percentage of unwanted acceleration cases are pedal misidentification, not a malfunction of the throttle system or the brake system.

When the Event Data Recorder collects this pre-impact data, it can show us What Really Happened. So the mechanical systems of the vehicle were operating properly, it was just a simple driver error.

Engine Failure

An automotive repair shop serviced a 2006 Ford F450 turbo diesel engine.  Roughly 100 miles later the engine failed.  GEI was assigned to determine why the engine failed and if the work performed had anything to do with the engine failure.

The repairs that were recorded on the invoices included replacement of the head gaskets, valve cover gaskets, and O-rings.  The truck had a little over 202K miles on it.

Our expert inspected the vehicle at a local Ford dealer.  The vehicle’s engine was partially disassembled before he arrived.

Engine after removal

The upper part of the right cylinder head, which houses the camshaft, was removed before he arrived.  The cylinder head was removed from the block at the beginning of his inspection, which revealed the internal damage and the cause.

Cylinder head with broken valve

The damage to the engine included a broken exhaust valve in the # 7 cylinder, which is the rear cylinder on the right, or passenger, side of the engine.  The top of the piston was damaged, as was the rocker arm for the #7 valve.

Top of damaged piston on the left

Combustion chamber for # 7 cylinder

The truck was equipped with a 6.0-liter turbo diesel engine.  This particular model possessed four valves per cylinder, two exhausts and two intakes.  As an internal combustion engine is operating, the temperature reaches 650 degrees C. at the exhaust valves.  Over time and mileage with the engine operating and then turned off repeatedly, the change in temperature can cause the exhaust valves to become brittle and, on occasion, break at the valve stem, just below the head of the valve.

That is what happened on this vehicle.  When the head of the valve broke from the stem, the head then fell into the combustion chamber, and became a loose foreign object.  The loose valve head made multiple contacts with the piston that was traveling up and down in the cylinder, damaging both the piston and the cylinder head. Some of the smaller broken parts transferred to other cylinders.  Minor damage was found on the # 3 and # 5 pistons.

The cause of the engine damage/failure was a direct result of long-term wear-and-tear.  The exhaust valve in the #7 cylinder broke from long-term wear and mileage on the vehicle, which in turn, caused the damage to the pistons on the right bank and to the rocker arms.

Invoices for earlier repairs detailing gasket replacements

The repairs to cure oil leaks that were performed 100 miles earlier by the shop did not include any work on the valves.

Our expert determined that the earlier shop repairs did neither cause nor contribute to the engine failure. 

Fire Wall

The Thomas Fire of 2017 was a massive wildfire that burned approximately 282,000 acres, becoming the largest wildfire in modern California history. The insured’s home in Ventura was threatened by the fire but not lost to it. It had three or four cords of firewood stacked in the back yard against a side retaining wall. The uphill neighbor had a driveway that ran along the edge of the retaining wall. The wildfire destroyed the backyard woodpile, the neighbor’s home, and over a thousand other structures in Ventura and Santa Barbara counties.

GEI was asked to examine the retaining wall between the properties and determine if all, some, or none of the wall needed to be replaced due to heat damage from the fire.

Our expert, Dr. Lamb, visited the home and examined the damage to the side retaining wall, the screen block wall between the front and back yards, and the concrete patio deck.

The fire burned away the strongbacks used in conjunction with wall anchors on the retaining wall.

Damaged retaining wall at right, screen wall in left background, and concrete patio to the foreground.

The heat of the fire also caused the wall anchors to expand and, in some places, deform.


Deformed wall anchors protruding from retaining wall.

All of the wall anchors were loose, and none were reinforcing the wall. The damage to the retaining wall extended 24 feet from the screen block wall.


Extent of the damage, as well as a view
of the concrete patio and screen block wall at left.

The retaining wall consisted of standard 16-inch x 8-inch x 8-inch Concrete Masonry Unit’s (CMU) that were solid-grouted. A wall this size likely had a foundation that was 16-inch x 12-inch x 8-inch CMU’s. Because the wall was solid-grouted, it appeared that repairs would require replacing 24 feet of the wall, including the foundation.

The failure of the retaining wall was observed in how it was overturning or leaning. It deflected from vertical by as much as three inches as measured from the top of the wall. This movement appeared to have also caused the failure of the screen block wall that divided the front driveway from the backyard.


Leaning retaining wall.


This CMU screen block wall developed significant cracking to the point that it could be pushed over by hand.


CMU screen wall showing various cracks.

About 13 feet of the screen block wall would also need to be replaced.

Finally, the heat from the fire caused spalling of the concrete patio deck and burned the material used for expansion joints in the slab. This slab covered an area of about 144 sq. ft. and appeared to be two inches thick in most places.


Concrete patio showing spalling and damage to  expansion joints.

In conclusion, our expert determined that 24 feet of the leaning retaining wall, 13 feet of the cracked screen block wall, and the spalling concrete patio would all require replacement due to heat damage from the Thomas Fire.


Expert of the Month:

Kenneth Lamb, P.E., PhD

Dr. Lamb is an Assistant Professor in Engineering at Cal Poly Pomona. He is a Registered Civil Engineer in the State of Nevada with 17 years of experience. His expertise in engineering covers hydrology issues, planned water/waste water facilities and storage facilities ranging from 700,000 to 20 Mgal, design of sanitary sewer pipelines, drainage studies for residential and commercial developments, and flood control issues.


A Door Dent

The Accord driver admitted to backing into the left side of an unoccupied Silverado pickup. The pickup owner said he was inside the vehicle and was injured. Did that really happen? Due to the claim timeline, the client needed a fast turnaround so GEI analyzed the accident and produced a report in under a week.

Typically this kind of analysis is a three-step process. First, the vehicle speeds are estimated based upon vehicular damage. Second, forces upon the occupants from the estimated speeds are calculated. Third, those forces are compared to the reported injuries to see if the forces experienced in the accident are congruent with the observed injuries.

The 1998 Honda Accord had some cosmetic scrapes to its rear bumper cover on the left rear corner. There was no other damage visible or reported to the Honda.


The 2001 Chevrolet Silverado pickup had a dent in the lower portion of the left door. The dent extended from the bottom margin of the door upward to the trim line. The dent was deepest under the left rearview mirror and tapered off to zero depth about midway in the door.


Our expert agreed that the damage to the vehicles was consistent with the left rear corner of the Honda making contact with the soft sheet metal of the left door of the Chevrolet, creating a shallow dent a few inches in depth along the lower portion of the door.

According to published standards, the Accord weighed 3,089 pounds, and the Silverado weighed 4,123 pounds.

When two vehicles collide, the difference in their speed and direction results in the total kinetic energy of their collision system. This kinetic energy is partitioned between the two vehicles inversely proportional to their weights with the lighter vehicle receiving the greater portion of the energy. The energy is dissipated through the bending of metal, the fracturing of rigid parts, plus heat and noise. The damage to the vehicles is the signature of the expended kinetic energy and also reflects the energy partition with the lighter vehicle showing more damage than the heavier vehicle. In this collision, the heavier Chevrolet had an advantage over the Honda. The Honda dissipated 57% of the collision energy while the Chevrolet dissipated 43% of the collision energy. While the damage to the Chevrolet appeared to be more severe than the damage to the Honda, the Honda was dissipating its energy through an energy absorbing rear bumper while the Chevrolet dissipated its energy through soft sheet metal that is not designed to attenuate energy. The damage to both vehicles was so minor that the energy partition was actually a moot point.

The Honda was equipped with a 5 mph energy absorbing bumper system. These bumpers are designed to absorb the energy from an equivalent barrier collision of 5 mph without allowing damage to structures beyond the bumper system. Ordinarily, when an energy absorbing bumper system approaches the limit of its resistance, there is evidence of permanent deformation to the bumper. In this collision, there was no evidence of permanent deformation to the rear bumper of the Honda. The damage to the rear bumper of the Honda was superficial cosmetic scratches to the plastic bumper cover. Lack of deformation to the Honda’s rear bumper system indicates the bumper was not experiencing a speed change close to its limit of 5 mph. Based upon this and the damage profile to the Silverado door, our expert concluded that the speed change experienced by the Honda was less than 3 mph and the speed change experienced by the Chevrolet was therefore also less than 3 mph.

Injuries in a traffic collision occur when the occupants riding in a collision vehicle undergo a very rapid change in speed or direction. That change must be so rapid that the body cannot move to compensate for the forces acting on the body. For example, anyone who stops at a traffic light from 30 mph undergoes a speed change of 30 mph. However, that speed change occurs over several seconds and the body easily adjusts to the change in inertia and no injury occurs. If that same 30 mph speed change occurs over a tenth of a second the human body cannot compensate for the high force acting on the body, which results in tearing of tissue and fracturing of rigid body structures. Before the human occupants in a collision vehicle can experience such a violent speed change, first the vehicle they are riding in must also undergo a similar speed change.

Absent a significant speed change to a collision vehicle, there is no potential for injury to the occupants in the vehicle. In this low speed contact event there was not enough energy represented in the damage to the Chevrolet to sustain a conclusion that the Chevrolet was moved off its footprint. At most, the Chevrolet experienced some rocking on its suspension but it was not significantly accelerated nor was its direction significantly changed. Absent any significant change in speed or direction of the Chevrolet, there cannot be a significant change in speed or direction to the occupants in the Chevrolet. The speed change experienced by the occupants in the Chevrolet was less than 3 mph. There was not enough intrusion into the left side of the Chevrolet to produce a bodily contact injury from the collision.

Based upon thousands of peer-reviewed studies, the minimum speed threshold for expected injury to occupants riding in colliding vehicles is a speed change of 5 mph or greater. In this accident the speed change experienced by the occupants of the Chevrolet was less than 3 mph.

There was no need for a discussion about or analysis of the nature of the Chevrolet driver’s injuries, because whatever they were, the backing of the Honda into the Silverado did not cause them.

An Inline Collision

Three vehicles were involved in an inline nose–to-tail, nose–to-tail accident. The insured, driving a Mercedes-Benz, rear-ended a second vehicle, a Scion. The Scion driver rear-ended the third vehicle, a Ram Laramie pickup. The question was, “Who hit whom, and who was pushed into whom?” GEI was assigned to review the materials provided and determine what was the most probable version of the collision.

Front of Mercedes-Benz

The materials provided included color photographs of all three vehicles and repair estimates of both the Mercedes-Benz and the Ram pickup truck. There was also a police report. It should be noted that there were only four photographs of the Scion, and they were of mediocre quality. They could not be enlarged without significant pixilation.


Rear of Scion

The Scion driver stated he had come to a complete stop and was then struck by the following Mercedes-Benz, pushing him into the Ram pickup truck. The insured stated that the collision between the Scion and the Ram pickup truck occurred first, and then Mercedes-Benz struck the Scion.

In a normal inline rear-end collision where the rear vehicle collides with the vehicle in front of it and causes collisions with the next vehicle or vehicles in front of them, we have a distinct pattern of damage. Because vehicle damage is a result of dissipation of kinetic energy, each collision has less and less energy, therefore causing less and less damage in each ensuing collision. So, the most damaged area would be the front of the rear vehicle and the rear of the first struck vehicle. There would then be less damage between the front of the second vehicle and the rear of the third vehicle, and so on for however many vehicles are involved.

Front of Scion

In this case, the damage to the front of the Scion appears to be equal to the rear damage. The most telling piece of evidence is the damage profile between the Scion and the Ram pickup truck. The collision damage on the Scion is largely above the bumper. The leading edge of the hood was involved in the contact. The damage to the rear bumper of the Ram pickup truck was much less significant than the damage to the Scion. What this damage profile indicates is that the Scion was in a heavy forward weight shift due to heavy braking. In other words, the nose was dipped downward most likely due to heavy braking. This caused the front bumper of the Scion to mainly slide beneath the rear bumper of the Ram pickup truck, causing the damage profile seen between these two vehicles.


Rear of Ram pickup truck

Had the Scion been stopped before the collision with the Mercedes-Benz, the rear-end collision would have caused acceleration to the Scion, potentially raising the front of the Scion, creating a different damage profile to the second collision. The damage would have been more bumper-to-bumper contact and less hood damage caused by an under ride.

When talking to the adjustor, the driver of the Ram pickup reported feeling two separate impacts. This is also consistent with the Scion striking the Ram pickup truck and then being struck by the Mercedes-Benz.

In summary, the most probable version is that the Scion collided with the Ram pickup truck, and then the Scion was rear-ended by the Mercedes-Benz.

A Wiring Issue

The Kia needed a new battery.


The owner of the vehicle asked for help from a tow truck driver. He agreed to help her and he replaced the battery in her vehicle.


Three days later she started to have electrical problems. Her turn signals didn’t work. Her taillights worked sometimes, and sometimes they did not. Eventually she took the vehicle into a dealership for diagnosis. They took a look at the vehicle and said a bundle of wires were crushed and exposed. The owner’s insurance company then hired GEI to find out what really happened.

Our expert inspected the 2012 KIA Forte at the owner’s residence.

The main fuse box was located under the hood, had all of the fuses in their proper location, and appeared to be in good condition. There were no blown fuses.


The fuse box located at the left end of the dash was the location of the turn signal fuse.


The vehicle’s owner stated that she replaced the fuse but it melted again when she operated the turn signals. The blown fuses had been removed and were not in the fuse box at the time of the inspection.


The wiring in front of the battery was damaged. It was partially crushed by a heavy object. The wiring appeared to have been caught between the battery and the plate below the battery location.


The damaged wiring had no signs of being cut with a tool such as a knife or wire cutting pliers. No other damage was found to the wiring in that location. The damage to the wiring located in front of the battery was in all likelihood a result of the recent battery installation. This most likely occurred when the battery was being lowered into position and the wiring was not pushed out of the way as the battery was lowered into place.

The wiring became caught beneath the battery and the support for the battery, and was crushed due to the weight of the battery. No other items or conditions were found that could have caused or contributed to the damaged wiring, which then caused the electrical problems.

Soapy Vandalism

The insured’s late model vehicle was vandalized with a white powder (possibly a cleaning powder or laundry soap) poured into the oil filler opening in the engine. After the vandalism was found, he reportedly drove the vehicle for three days, at which point, it would no longer run. He then turned in a claim to the insurance company for the vandalism damage. GEI was brought in to answer the following questions: 1) Was there damage from a forced entry to the hood or elsewhere? 2) Would we observe the mechanical disassembly and inspect and report on the observed damages? 3) What would an oil analysis tell us?

The exterior of the vehicle was examined and was found in very good condition. The hood was found slightly ajar, as the engine had been partially disassembled prior to our inspection. As the exterior of the vehicle was being examined, the owner stated that he always kept the vehicle locked when it was not in use. Our expert inspected the vehicle for signs of forced entry. There were none. The hood was not opened from beneath the vehicle or from unlatching the hood from the exterior of the vehicle. The initial step in releasing the hood was to pull the hood release lever located in the passenger compartment under the left side of the instrument panel. This mechanism was not modified or altered, it functioned normally when inspected. No other indicators of forced entry were found on the hood, doorjambs, window frames or door handle areas that would indicate forced entry to the interior.

The hood was opened to access and examine the engine compartment. A granulated substance, such as salt and/or sugar was found on the air filter. The cylinder heads and the air intake manifold were exposed for examination. A powdered substance, possibly a cleaning powder or laundry soap, had been poured into the engine oil filler neck on the front of the left side valve cover. The color and distribution of the powder indicated that the engine either had not been run or had run only a short distance prior to its disassembly.

Red boxes indicate powder contamination areas


There were no indications that this white powdered contaminant traveled through the lubrication system. The timing chain was not contaminated with the powder, despite it being in close proximity to the oil filler inlet. This was further evidence that the powder contaminant did not travel through the engine oiling system. Additionally, the engine oil filter would have protected the oil pathways from contamination.

Our expert drew an oil sample and sent it to the laboratory for analysis.

The laboratory report indicated an abnormally high wear pattern to the engine’s internal components. The amount of particulates suspended in the oil sample indicated long-term mechanical issues. The report also indicated a problem within the cooling system. The contaminants found covering the components and inside the engine compartment components did not appear to have affected the condition of the engine oil.

Portion of Oil Analysis Report

The engine oil analysis report indicated an abnormal wear pattern within the engine’s internal components. The elevated levels of iron indicated wear to the cylinders. The grossly elevated count of aluminum particles, well over sixty-two times the maximum amount, indicated that the pistons had deteriorated badly. The presence of chromium indicated piston ring wear. The high level of copper along with the presence of tin and lead indicated advanced wear to the engine bearings and/or valve guides. These indicated that the engine was badly worn, and combustion gases were bypassing the piston rings leading to poor engine performance, and increased levels of pollution.

Advanced wear can be caused by detonation and pre-ignition, also known as ‘pinging’ or knocking’, caused by using low octane gasoline or by carbon deposits in the combustion chamber increasing the compression ratio and requiring higher octane gasoline.

There was also a high level of fuel in the sample, which exceeded the alarm limit. This lowered the engine oil’s lubrication ability and, coupled with the other observed damages, would cause the oil pressure to drop. This fuel dilution or contamination would normally also cause higher wear. Fuel can enter the engine oil when a fuel injector is stuck open causing fuel leaks or the cylinders to misfire. If the fuel pressure is too high, fuel can also be forced into the engine oil.

The report also indicated a failing or failed cooling system. The very high level of potassium, over six times the maximum amount, the very high level of sodium, over twenty times the maximum amount, the very high level of silicon, over five times the maximum amount and the presence of water, indicated a severe cooling system issue. The presence of water in the oil sample could indicate a failed head gasket or a cracked cylinder head, which are normally a result of the engine overheating.

The above list of failures indicated that the deterioration of the engine had been occurring over an extended period; these results would not have developed from the recent white powder contamination issue. The engine was overdue for replacement, but the cause was not the vandalism of the laundry powder in the oil.