My '99 F-150 SC Lariat 4x4(4.6L V-8, automatic) is the first automatic tranny vehicle I've owned. I live in the mountains, and on the highway, sometimes like to coast in neutral on the downgrades to give the engine a rest and help with mileage (old habit from driving a stick).

I have never been able to do this with the F-150 however. If I'm crusing at highway speeds, and shift into N, the engine revs up to about 3K rpm and stays there even though there should be no load on the motor.

My work truck is a 2002 Chevy Silverado 4x4 with an automatic, and when I pop it into N on a downgrade, the engine rests at idle rpms.

Does the Ford have some kind of safety feature to prevent me from doing this, or does it sound like something may be wrong?

Thanks for your help.
Jeff F.
Weaverville, NC

 

Its normal, just a condition where the computer sees a high vehicle speed and keeps the IAC open to keep the RPMs where if you slide it back into gear it will be almost matched. I would say just leave it in gear.

 

Them DAMN computers strike again!!!!!!!!!!!!!!!

 

Lets say someone is coasting downhill in neutral, engine at idle. Then the driver puts it back into drive, and there is not good traction (rain, sand, slick tires, etc.) Guess what, the rear tires are gonna slide and spin the truck around before the engine comes up to speed.

 

Definately not something I would do in a potentially dangerous situation; ie. bad weather, traffic, steep downgrade, curves, etc.

Once in a while the conditions are ideal and inviting for me to coast, and with a stick I never had any kind of problems when I shifted from N to 5th. No different than downshifitng from 5th to 4th when you want the engine to help slow you down.

Anyway, we just did a 2K mile trip up and down mountains the whole way. There were a few occasions when I would have liked to have been able to do this.

It is curious how the Silverado with an AT will let me coast while the Ford won't, but maybe we're comparing apples to oranges.

 

dunno

 

Just posting humor Jefflaws. My truck runs as good as it does because of the computer.
Also, I enjoy reading your input. Keep it up...

 

NoProb.

 

ncferguson,

i was just out on the highway last night going 65 mph and put my truck in neutral.....the engine speed dropped to normal idle rpms while coasting in neutral. i put the tranny back into drive and for a brief time the rpms jumped up until it settled back into overdrive and the torque converter clutch locked back up....

not sure why mine is acting differently then yours. i have the 4r70w tranny and presume you do too...

 

Yup,

That's what I'm going on about. Something about this just doesn't seem right. I too have the 4r70w tranny. I would really like to know what is normal here particularly for my model year (1999).

I am wondering if something could be wierd with my computer, or if there might be a problem with my torque converter.

Sometimes my shifting seems a little clumsy compared to the '95 Bronco that I used to drive as my work truck, and definately compared to my current work truck (2002 Chevy Silverado 4x4). I keep telling myself that I just need to get used to the F-150. Every other automatic I drive or have driven seems to behave more like I would expect one to, while the F-150 just feels strange.

I would love to hear how other peoples trucks behave as far as this goes, and any suggestions as to how to clear up this question.

Thanks again for the input.

 

i don't notice any really odd shifting behaviour with my truck...except that occasionally the 1-2 upshift can be harsh. the rest of em are smooth.