OK, so my waterpump went out and my 02 grand caravan 3.8l v6 overheated. Now I have a backfire inside the the air intake. Im wondering what is causing it. I've put the stethoscope on everything and the only noise is in that intake manifold.

Thank you for any help.

Intake valves are not closed fully when the spark takes place.
Overheating may have warped the head.
Have a leakdown test done to see what cylinder isn't closing

You have burned intake valve to seat or hole in the intake valve ! Pull each plug wire one @ a time till you find the skip or dead cylinder !! Lovvorn

I would also add to the other members had said, The backfire is cause by the engine running poorly. Before doing a leak down test, do a dry compression and wet test. Then a leak down test. And if you are hearing a noise in the intake manifold, remove it and inpect.

Thanks for the input guys. It's looking like I will be tearing into it in the next week. I will post up what I find. Also it sounds like there may be a knock, but I'm not sure.

*update*
So far I've found a broken rocker arm. Waiting on the parts now. The compression test came back good. All cylinders read 180+. Anything else you guys think I should look into?