Weird Idle

[tonyroc14]

Bone stock 1998 Explorer Sport. 4.0sohcv6

Ok so the CEL is on, and the truck has a weird idle. It will idle from about 600 to 1100 rpms. It will consistantly switch from 600 too 1100 about every second, they are smooth. I was thinking vaccum leak, but i wasnt aware that a CEL will be desplayed. These are also the only symptoms, and it doesnt do this while idleing in gear. Also, it only does it when i first start the car. For example, i went to get a drink just now, and i started it, it was doing its crazy idle, i back out of the garage, put it in park, and it was steady at 600ish. Also the car was still warm from my previous use. I believe the ICV was replaced recently as the car had no idle at all, had to power brake around town all day, quite anoyying. Anyways, i am open to any sugestions, and i am going to begin my search with "idle," thanks.

 

[tonyroc14]

nobody?

 

[aldive]

What was the trouble code(s) that triggered the CEL?

 

[jeff26]

Same problem

I have the same issue going on. Thats how I found this site.

 

[tonyroc14]

What was the trouble code(s) that triggered the CEL?

i dont know. Is there a way to get the codes? On my other car if i have the car in accesory and floor it 5 times in 10 seconds it gets me the codes.

 

[aldive]

Get the codes via an OBD II scanner or code reader.

 

[tonyroc14]

Get the codes via an OBD II scanner or code reader.

damn't.

 

[dogfriend]

Look for a vacuum leak - look at all the hoses connecting to the intake manifold to make sure one didn't fall off.

I had this happen with the Ranger that I used to have except that it happened after I replaced a vacuum line that got knocked off. I then removed the battery cable to make it "relearn" the idle and the problem went away.

 

[TrevoJreal429]

Go to a auto zone or like store and they will pull the code for free.

 

[tonyroc14]

Look for a vacuum leak - look at all the hoses connecting to the intake manifold to make sure one didn't fall off.

I had this happen with the Ranger that I used to have except that it happened after I replaced a vacuum line that got knocked off. I then removed the battery cable to make it "relearn" the idle and the problem went away.

I was going to start to search for a leak tomorow. I can tell you that it sounds diffrent.

Go to a auto zone or like store and they will pull the code for free.

thats pretty sweet, i am going to have to go check it tomorow. I will return with a code, and a progress report on the vacuum leak, or lack there of.

 

[Dre]

Open the hood... start the engine and listen - make sure there are no strange sounds - especially hissing.

I just had the same thing in my 2002 Sport - found out today that one of the rubber elbows has a hole. Have to replace that.

Other than that check if the 00M12 recall has been taken care off (camshaft chain tensioner)

 

[Cobraguy]

That's called a rolling idle. Unfortunately, it's not all that uncommon on Fords as their idle system is pretty sensitive. Fortunately, it's usually easily fixed.

When they replaced your IAC valve...do you know what brand and part number they used? Ford's can be very sensitive to the correct IAC.

Do you have any modifications to the filter?

Have you cleaned the MAF sensor?

And of course, vacuum leaks should always be suspect.

 

[tonyroc14]

Open the hood... start the engine and listen - make sure there are no strange sounds - especially hissing.

I just had the same thing in my 2002 Sport - found out today that one of the rubber elbows has a hole. Have to replace that.

Other than that check if the 00M12 recall has been taken care off (camshaft chain tensioner)

Ok, i will see if the camshaft tensioner has been fixed. I dont see how this can cause a funky idle and a CEL. But it is still something important to do. I will also be looking for a vacuum leak, witch i am quite positive there is one, since there is a hissing noise.

That's called a rolling idle. Unfortunately, it's not all that uncommon on Fords as their idle system is pretty sensitive. Fortunately, it's usually easily fixed.

When they replaced your IAC valve...do you know what brand and part number they used? Ford's can be very sensitive to the correct IAC.

Do you have any modifications to the filter?

Have you cleaned the MAF sensor?

And of course, vacuum leaks should always be suspect.

Yea i have no idea what they put on, it was serviced at the dealer tho, so they probably used OEM parts. But i will go and check to see what they used. Also, i am going to be cleaning the MAF on my other car and might as well do it to this one as well. Everything on this car is stock, so is the air filter. This is not the first time I had a problem with the idle. A couple months back we had no idle at all, had to give it gas while at lights and stuff, a real pain in the ass.

I am going to get the code pulled today, search for a leak, witch i swear there is one, as the gas mileage has been hurt a little bit. I have not noticed a lack or performance tho. The only problem is the funny idle. Thank you guys for the help. Once question, where is the ICAV located at? Also are there any PDF manual or something? Once again thank you.

 

[tonyroc14]

so without me even knowing my dad took the car to the stealer. Intake manifold gasket was bad. All is well now.