My 01 2500hd with the 8.1 motor has bad manifold leak on drivers side. It ticks when under load. I have broke 3 bolts off when taking it off and the last bolt will not come loose or brake off. I broke 2 sockets on it and now its starting to round off.. I am getting a strange screaming high pitched sound also and it sounds like its coming from the gasket or inside manifold. It happens at around 1200 rpm then stops and if I rev motor it will get very loud when motor is coming back down to 1200 or so. Is there and way that could be caused by the leak as well. It is crazy sounding, besides the tick that is the only issue. Can I heat bolt without hurting the head.. I was maybe going to trade it in Monday on a 04 duramax but really don't want a payment. That high pitched sound bugs me not knowing what it is.