One morning started up the engine on my Audi, and the engine sounded like it had rough idling, stuttering sound to it. I had took it for a test drive and experienced lack of power, hesitation in engine, rough idling, and then check engine light came on. Checked out the code. It came up to be (P0304) cylinder 4 misfire. I took it to a mechanic, and he replaced spark plugs, coil packs. The problem still existed. He had checked the compression. It was good. Check all wires, senors...ect. Anything he could think of and it all checked out good. Timing belt and water pump was replaced couple months before this problem existed. The problem only exists when the engine is cold. Once you warm up the engine, restart the car, and it drives perfectly fine! engine cools down, and rough idling, lack of power and all the comes back again. The mechanic doesn't know what the problem could be.

- Spokane, WA, USA