Why is my return line cracking on my GMC Sierra 1500?
Why is my return line cracking on my GMC Sierra 1500? So you cracked on the return line. It should naturally drain. If the flow/pressure increased when the truck started that means that you are sucking fluid from the pan therefore the pump is working. That means that the problem is most likely in the valve body. What are the symptoms of a misfire in a GM Truck? The core symptom of a misfire is rough idle. This isn't the only symptom that your GM van, pickup or SUV might experience... here are some more that you might see: P0300:...