issues plagued the engine. Faulty valve-stem seals caused excessive oil consumption, but this was not addressed until the release of the updated Dura-built engine in 1976. According to an article in Popular Mechanics, "When the engine got hot, which wasn't uncommon, the cylinders distorted and the piston rings wore off the exposed silica that was meant to provide a tough wall surface. Then, at best, the cars burned more oil. At worst, the distortion compromised the head gasket." With its small capacity and tiny two-tube radiator, the Vega cooling system was adequate when topped off, but owners tended not to check the coolant level often enough, and in combination with leaking valve-stem seals, the engine often ran low on oil and coolant simultaneously. Consequent overheating distorted the open-deck block, allowing antifreeze to seep past the head gasket, which caused piston scuffing inside the cylinders. Chevrolet added a coolant-overflow bottle and an electronic low-coolant indicator in 1974 that could be retrofitted to earlier models at no cost. Under a revised engine warranty for 1971 to 1975 Vegas, the owner of a damaged engine could choose a replacement with a new short block or a rebuilt steel-sleeved unit, which proved costly for Chevrolet. GM engineer Fred Kneisler maintains that too much emphasis had been put on overheating problems, the real culprits being brittle valve stem seals and too-thin piston plating. Regardless of the cause, damaged cylinder walls were common. Fisher Body On the early Vegas, Fisher's rustproofing process did not treat the entire chassis. The six-stage zinc phosphate rustproofing process began with the untreated steel body shells spending two minutes submerged in a electrophoretic painting vat (Fisher Body Division’s "Elpo" electrophoretic deposition of polymers process) to prime and further protect from rust. Assembled bodies were dried, wet-sanded, sealer-coated, sprayed with acrylic lacquer and baked in a degree oven. However, there was a process failure during the vat treatment stage because a trapped air pocket prevented the anti-rust coating from reaching a gap between the Vegas’ front fenders and cowl. Under normal driving conditions, this allowed moist debris and salt to build up and rust the untreated steel on early Vegas because they had no protective liners. The finance department had rejected liners as they would have added a $2.28 unit cost. After GM spent millions replacing thousands of corroded fenders under warranty, Chevrolet installed stopgap plastic deflectors in late 1973 and full