I’m hearing a disconcerting sound coming from my car as of late. It’s a rattling sound, almost as if someone were shaking a can of spray paint at the same frequency as the engine. It doesn’t strike me as being a heat shield, it’s a heavier rattling, not really a buzz.
The sound usually occurs when I am above 2000 RPM, however, it does not match an RPM range or the car’s speed—it seems more closely associated with the position of the gas pedal—about halfway to 3/4. It does not make the sound unless the car is in gear and moving.
On cold starts, the engine fires and runs, but then takes up to 30-40 seconds to really get going at a normal RPM. Efforts to coax it with the gas pedal are delayed by a second or two before they kick in…
The car is a 2001 model, and has 44,000 miles.