01 Expedition RPM Problem

Pancho_1973 · 06-12-2008, 10:45 AM

Hello To All,

I am new here and looking for some advice. I posted this in the new members section and am posting here as well in hopes of getting a better response. I have an "01" Expedition XLT 4.6L 2WD with 83,000 miles. At the stop light while idling, after the engine is warmed up, the RPM's will drop from 600 to 500 and then back up again. This will happen 2 to 3 times before the light changes. In addition the engine almost sounds like it's panting like a dog. Heavy breathing. With the heater on RPM's are stable, however the panting sound is more prominent. I've replaced the hot and cold valve, fixed a vacuum leak, and replaced the egr valve. Problem still persists. Any advice would be greatly appreciated. Thank You.

TBIRD430 · 06-13-2008, 08:58 AM

Try adding a can of Seafoam brand fuel treatment to 1/2 a tank of gasoline. Then remove and clean the Idle Air Control valve. I would also recommend u buy a good ELECTRONIC CLEANER at parts store, remove and clean the Mass Air Flow Senor then drive & get back to us. I would do 1 at a time so u will know which part was causing the problem. But in the end, they ALL need 2 B "to serviced"...

Pancho_1973 · 06-13-2008, 09:48 AM

Thanks for the tips. The idle air control valve is new. I replaced it thinking that was the problem. It seemed to help a little, but the problem hasn't gone away. I'll take your advice and get back to you. I hope the MAF doesn't need to be replaced. The dealer wants $250 for it. Then I would have to change the O2 sensor as well. Pricey. Thanks again.