2003 Explorer 4.6 V8 High Idle Problems

[hawknose]

My 2003 4.6 V8 has a high idle problem. During warm months the engine will idle from 1500 - 2000 rpm. Real problem when coming to stop when it will bang into first gear before stopping. Dealer first said it was the idle air control. Replaced idle air control myself with a new ford one. No difference. Then read that I should disconnect the battery for a few hours, then connect, crank and idle in park, then in drive and then reverse for the computer to learn the idle patterns. That seemed to work for awhile. The car has not had the high idle almost the entire winter. Now that things have warmed up, it back to it's high idle problem. Does not do it all the time. Has anyone else has this experience. Please help.

 

[Number4]

You may have a bad fan clutch.

Also, the clunk when coming to a stop sounds more like the transmission solenoid.

 

[hawknose]

Not transmission. It is fine when there is not high idle. Fan clutch is good. Thanks for the reply.

 

[ROBinGa]

Check the hoses that connect to the IAC you replaced. Especially look at the one that has a rubber elbow and make sure that the elbow isn't cracked on top or bottom. There is a great thread on here somewhere about this common problem and my 03 4.6 sure had it. It was a cracked rubber elbow and after replacing that entire hose assembly engine ran and idled properly.

 

[hawknose]

Thanks. I saw a post about these hoses and how to order the correct ones a while back. If anyone can find post that, many thanks.

 

[Cdub42]

Maybe take a look at the throttle position sensor? Just a thought.

 

[BigRondo]

Maybe take a look at the throttle position sensor? Just a thought.

X2.

I recently changed mine due to high idle.

 

[ROBinGa]

Do a search for Sybertiger who posted that thread about hoses. Here's the title of it
Rough idle and "Check Engine Soon" light - FIXED

I don't know how to post the link to it though

 

[BigRondo]

Do a search for Sybertiger who posted that thread about hoses. Here's the title of it
Rough idle and "Check Engine Soon" light - FIXED

I don't know how to post the link to it though

Here you go:

http://www.explorerforum.com/forums/showthread.php?t=217062

 

[scottfab]

My 2003 4.6 V8 has a high idle problem..........

I will add this. If you have a wondering idle look to the elbow issue (small crack) mentioned in this tread BUT if you have a solid high 2000 rpm idle that does not wonder then look for a complete or partial open of the hose either at the big 3in intake tube or at the other end near the elbow. Fixed mine. AND the hard clunk on downshift went away as well !!!
OH and rather that futz with trying to find an elbow I just put in straight rubber tube that makes a long curving elbow. YOu have to route it out farther toward the front of the engine Works.
The air leak at this point is unmetered air which causes the high idle.