Hey guys,

Our 2000 explorer xls 4x4 with 4.0 ohv just pop the code for the intake gasket leaking. My question is, would there be any way to tell if it is the upper or lower that is leaking? It has 188k on it but still runs good. I think I can feel a miss in it at idle but it is not a steady miss. Any help is appreciated.

 

Ken--If you can't see an obvious leak (coolant or oil), I've seen some guys use the starter fluid or propane technique. Spray starter fluid (or carburetor cleaner) around the intake gasket areas and listen for a change in idle speed. Same concept with propane: Fashion a hose attachment that allows you to put small amounts of propane gas around the gaskets.

Of course, there are inherent risks to putting flammable liquids or gases around hot engines, so keep the amounts small and decide if it's a risk you're willing to take.

I used the propane technique to try to find my intake vacuum leak. Didn't do a thing for me and yet I had a pretty sizable gasket failure on my fuel rail.