high idle and gas mileage

[andymikem97]

I just bought an 05 Escape for my son. It has 101K on the clock, 3.0 6 cyl. auto. It seems to run great, lots of pep, and drives pretty well for the mileage. The problem is that when first started, it idles about 1300 rpm for a long time before settling down to about 850-900 rpm. The colder it gets, the longer it takes to calm down. This morning was 34 degrees outside, and I waited almost 10 minutes for the idle to settle. Was still at around 1000 when I started off to work. The second issue is the fuel mileage. I filled the tank, put 45 miles on it, and am now down to 3/4 tank. Air filter is new, just changed over to 5w20 full synthetic, the intake gaskets were replaced at 72K (I have the full service records). No codes, and as I said, she runs really nice. I figured it should get around 18020 mpg, but at this rate I'll be lucky to get 15 out of it. I see other folks on here are having the same mileage issues. My question: are the high idle and crappy gas mileage related? Causes? Thanks for any suggestions.

[65comet]

I would suspect the Idle Air Control Valve (IAC) is dirty and needs cleaning. You can search YouTube for videos on how to do the cleaning.

[Stealthee]

1000 rpm isn't all that high for a cool morning. The gas mileage could be related to the higher idle, cooler temps, and winter blend fuel, however you can't base your gas mileage on what your gauge says. It may be inaccurate, so you need to fill it up after you get some more miles on the tank and do the math.

[andymikem97]

I put some sea foam injector cleaner in The tank. I'll run a few tanks through to see if anything changes and post back. Thanks.

[andymikem97]

Update.
This last tank I got 19.66 mpg. I think it should be better but I'll take what I can get. Still have the high idle at start, but I notice that if I pull it from park straight into neutral, and back to park, the idle falls from 1500 to about 1000 and stays there.
2nd thing I notice now is a high pitch squeal at part throttle. Goes away when more pedal is given, and when I coast. Just hear it at part throttle.
Other than little stuff, I really like driving it. Cranks for 2-3 seconds and fires up every time. Drives nice and is more quiet than a lot we test drive.

[65comet]

Just an FYI on mileage. My '02 V6 4WD with wilderness kit (taller roof rack and all terrain tires) would average 28 highway and 22 around town with me driving. My wife driving, always around town and lead foot, it would get 15.