I think on the early ones, there is a beep..... The same one that you hear when the low fuel, or CHECK GAUGE light comes on. When my ICP was failing, the light would clear and set, I think it beeped each time the light came on.
Dogman,
Not sure on your issue. Could it be a voltage or some other issue? How about an EGR Valve issue, if you still have one. On the newer trucks, an EGR Issue or Delete will cause a Check Engine Light, so will an overboost. Was this during or after a "hard" acceleration? Just throwing out ideas.....
The reason I asked about voltage issues, I had a 92 Bonneville. I had a transient issue where the "Check Gauge" light would quickly flash, and the warning beep would cycle with the flash. What I finally found was the voltage regulator in the alternator was beginning to fail, and go "high" What would happen as it would run, the voltage level would "bounce" and go just up to the high warning area in the voltmeter in the dash. As it would bounce and touch this area, it would set off the beeper and flash the light. It would only do this 5 or 6 times, and then not do it again for some time. I was doing something else one day, and happened to be looking at the voltmeter when it had one of its "spells" and I saw what it was doing. Replaced the alternator, and the spells stopped...... Just an idea.