By the first quarter of 1977, some 43,000 Delta 88's had been produced with the Chevy powerplant. This represented about 57% of the overall Delta 88 production.
Since the engines were practically identical, and some Chevrolet versions even had the "Rocket" sticker on them, this whole thing could have gone by unnoticed. Unfortunately for GM, it did not. In early 1977, Joseph Siwek of Chicago took his Delta 88 into the mechanic to have a fan belt replaced. This should have been a relatively simple job. However, after waiting an inordinate amount of time for his car to be repaired, he asked the mechanic what was taking so long. He said that the parts he had, for some reason, did not fit Mr. Siwek's car and he had to order a new belt from Chevrolet. This led to the revelation that the engine under the hood of Mr. Siwek's Delta 88 was not the Oldsmobile "Rocket" for which he had paid a premium, but in fact a similarly sized Chevrolet engine. Mr. Siwek immediately filed a complaint with William J. Scott, the Illinois State Attorney General, who opened an investigation. This led to the revelation that GM had substituted had not only substituted the Chevrolet version of the V-8 in over half of the Delta-88 production, but also had substituted it into similar Buick and Pontiac models as well. Mr. Scott filed charges in March of 1977 in Cook County circuit court in Chicago claiming that GM had violated the Illinois Consumer Fraud and Deceptive Trade Practices Act by failing to publicize the engine switch. If convicted, GM could have been fined $50,000 for each Chevy-powered car sold in Illinois and the dealers could have been fined another $50,000. This was a substantial amount considering that the car itself only cost around $10,000.
GM initially stonewalled, claiming that it had not broken any laws. That had notified dealers immediately of their intentions in the previous Fall and it was their responsibility, not GM's to notify the consumer.
