So I put a new serpentine belt on my truck Saturday afternoon, and it's got a phantom coolant leak. It was a tiny bit below the cold fill mark, and I don't recall it ever being right at that mark, if I'm honest. I drove a cumulative 200 miles since I noticed it was low. Today, I popped the hood, and the tank is significantly more empty than it was Sunday. I smell coolant when the engine is hot every now and then, and not much more than that. It was 25 degrees yesterday morning and the heat cranks. It's had a P0128 code for about two weeks now, I have a thermostat ready to go in, too. The only line missing any clamp was the radiator to expansion tank return line, except it's tight and doesn't appear to leak. The water pump also doesn't appear wet.
Any tips out there?
Any tips out there?