Chris Jones
Member
Lately I've heard an odd hollow, metallic sounding thunk from the truck several times while not running and I think once while idling for varying periods of time. It sounds exactly like and old square sided metal gas cans contracting and expanding due to temp fluctuations. Only one thunk per day or maybe one AM and one PM use. But I think my tank is plastic. I've never heard it before in almost 14 years. I'm a bit perplexed at what the sound would be. I'm wondering if it is the muffler but that's open via the tail pipe so it shouldn't be expanding or contracting. I did notice a fair amount of water draining from the weep hole in the muffler the other day when parked uphill on a paved drive. Truck runs/drives fine. Any ideas?