This morning when I started up my truck I noticed a slight knock just before it started. After that it started fine and drove fine. I stopped at the store and came back out and started it up and no noise. I drove to work and it sat for about 7 hours and I heard the knock again just before it started. The lights in the dash also went out and came back on the same time I heard the knock. I am wondering what this noise is, because it doesn't sound good. Any ideas?

 

Lol when it was i guess -14 the other day mine made a horrible noise like a cat was under the hood. I'm not sure what it is but i notice that it onlys happens when its from 10 degrees an lower. It only makes it for a second.

 

Ok, I was just wondering, I didn't want to hurt anything this engine is pretty worn out, so I try to be careful.