Hi all: A few days ago I drove 375 miles from Pennsylvania to New York State in my ’93 Bonneville SE (100,000 miles). About 40 miles from home, on an interstate highway, I punched the accelerator to pass another car. My passing speed was probably 70 to 75 mph. When I got past the other car, I noticed that the Service Engine light was on. The car would not shift from passing gear into overdrive, and the rpms were at almost 3,000, instead of the usual 2,200 at highway speed. After 20 miles or so, the car shifted into overdrive, the Service Engine light went out, and the rpms dropped to normal.
The next day, I was on a city expressway, and the same thing happened. After I passed a slower-moving car, the Service Engine light came on, the rpms were higher than usual, and the car would not shift into overdrive. Today, I ran the car to warm it up, and the Service Engine light was NOT on and the engine idled at its normal rpms.
The Service Engine light has come on once or twice since I bought the car six months ago, but it has stayed on only for a minute so each time. When I bought the car, I replaced the catalytic converter. The day before leaving Pennsylvania, I added about 8 ounces of transmission fluid.
Does anyone have any idea what might be going on? And what should I be looking for if I take it to a repair shop and have it put on a computer scanner?
Thanks in advance.
*** Thread moved from Chat ~ Kevin ***
Last edited by Captain Bonneville; 01-02-2010 at 08:48 PM.
Reason: added year and model to headline