The last couple weeks i have been starting my engine and there was a rattlting sound every few seconds just for a seconds and then it would go away. If it is freezing outside it doesn't make the sound, and also after the engine warmed up the noise stopped. There was no performance loss, and the engine light never came on. Some info about the car is i bought the car with 110,000 miles on it, and the clicking was not there in the beginning. The clicking sound seems to be coming from the down pipe, im pretty sure, i have heard it could be the pistons or the water pump, but the sound comes from around the downpipe, not the front of the engine.
Any help is greatly appreciated.