I have to redo the intake manifold on my truck......i really thought i did a good job the first time but apparently i didnt. I was reading some past posts on this subject and it was mentioned that gray rtv was pretty good. I used orange the last time. Maybe i didnt let it sit long enough or maybe while installing i slid the intake slightly and didnt know it messing up the seal action. I was wondering why i was getting hard starting after a while...i could see a small coolant puddle on one side. If my temp gage was working i would have known it was overheating....that is before i noticed the small coolant puddle....:-)