tapping noise when below 40 degrees
I have a 2002 jeep G/C with the 4.0 inline six with 127,000 miles. When the temperature drops below 40 degrees outside is when it makes this noise. It's a tapping noise,but doesn't change sound or tempo when I rev the motor and only does this when it's cold out. It takes a couple of minutes for it to start making this noise after I start it too. And it doesn't change when the engine warms up either. But as soon as the outside temperature goes up,it's quiet as can be. Just has me baffled, because it doesn't sound like anything internal like a lifter or something. Any help would be greatly appreciated! Thanks,Keith.