I have a 97 F150 4x4 with a 4.6 and I put a cold air intake on it. When it is cold out the truck will make a buzzing/vibrating sound and idle up about 800 rpm. If I rev it up then it will go back to normal idle. It never did this before the intake was put on so I'm pretty sure the cold air intake is causing this. I'm pretty sure I installed it correctly too. Does anyone else have this problem? Or is just because it is a cheap intake from ebay that is junk? I don't want to buy an expensive intake if it is going to do the same thing. Please help!!!

 

I have a K&N cold air intake and it doesn't make any noises hot or cold out...and it gets very hot and very cold where i live(about 20-113 degrees!!!) it might be ur instalation or the intake kit itself! My advice is to get a K&N!!!