In the September/October 2004 issue, we responded to a reader's question regarding the catastrophic mechanical failure of a 6.6-liter Duramax diesel engine in a 2002 Chevy truck. He was looking for advice on dealing with General Motors' refusal to replace the irreparable engine after an extensive valvetrain breakdown, which was technically covered under the vehicle's powertrain warranty. GM's zone service representative disputed the claim under the assumption that a recently installed Gale Banks Engineering exhaust brake assembly was the cause. An exhaust brake, used to amplify engine braking on a diesel engine, does have the potential for producing excessive backpressure, which can cause valve float and lead to valve-to-piston contact.
In that issue of Truck Trend, we left off with GM's claim that the exhaust brake did the damage and Gale Banks Engineering representatives stating it was an unrelated internal engine defect. Meanwhile, the owner reluctantly paid $21,885 to replace the entire engine, along with a $3500 core charge to retain the damaged goods as evidence. He then obtained legal representation, refusing a $10,000 offer from GM.
A year later, the verdict is in. All parties finally arrived at the mediation table, where the complainant produced an engineer's report on the failed engine. The report implied that metal fatigue in a valve stem, possibly due to a bad batch of materials, caused the valve stem to break, which initiated a chain reaction of damage in multiple cylinders. While Gale Banks Engineering was satisfied with this, GM's legal representatives, claiming they were unprepared, left the table and later notified the owner they would schedule time for their own engineer to inspect the engine. GM specialists never followed through with the inspection, but did discuss the failure with the engineer who delivered the report on behalf of the owner. Shortly thereafter, and without claiming responsibility, GM offered the owner a check for $67,857. This included buying back the truck at the original price (minus a $12K usage fee for three and a half years owned), parts, and labor for the replacement engine and all legal fees rendered. Gale Banks Engineering also remitted $3750. The former Chevy driver accepted the agreement, which put him back on the road in a Dodge Ram with a Cummins diesel, minus the exhaust brake.