Idle issues

Asked by Afstuve Jan 01, 2017 at 03:21 AM about the 2002 Ford F-150 XL SuperCab SB

Question type: Maintenance & Repair

I have a 2002Ford F150 and am having unsteady
idles urging when in drive and brake is applied,
stalling also when in drive and brake is applied
then released.  Have also noticed hissing from
front and rear of truck along with a pumping,
putting sort of noise as well. Not sure whether this
is a fuel pump issue, air flow sensor, vac. line leak,
or some other issue causing all of this.  Appreciate
any help that is given as I am able to perform
certain repair &maintenance on truck but am
limited in my mechanical skills.

2 Answers

157,115

It is possible that there is an issue with the power brake booster. The booster is supplied with vacuum from the intake manifold. This vacuum is used in the booster to amplify the pressure you put on the brake pedal when stopping. I would first locate the booster vacuum line that runs between the manifold and booster and make sure it is not cracked or otherwise degraded. If it looks good I would suspect a faulty brake booster and replace it. The loss of vacuum is likely the issue as to why it is not running correctly properly. The vacuum leak could be from somewhere else under the hood also.

I have the exact same truck with a 5.4l that has this issue. The plastic intake manifold is known to crack which causes a vacuum leak. Dorman makes a replacement manifold with upgraded O-ring gaskets for about $200. It takes a couple of hours for a home mechanic to replace it.

Your Answer:

CarGurus Experts

  • #1
    OJ
    Reputation
    41,770
  • #2
    Gene Arnett
    Reputation
    15,990
  • #3
    Rowefast
    Reputation
    15,420
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Chevrolet Silverado 1500
213 Great Deals out of 9,034 listings starting at $2,900
Used GMC Sierra 1500
188 Great Deals out of 8,956 listings starting at $1,000
Used Toyota Tundra
33 Great Deals out of 988 listings starting at $9,240
Used Ford F-250 Super Duty
34 Great Deals out of 719 listings starting at $4,290
Used Toyota Tacoma
43 Great Deals out of 682 listings starting at $9,975
Used Dodge RAM 1500
86 listings starting at $7,995
Used Ford Mustang
54 Great Deals out of 1,606 listings starting at $6,200
Used Ford Ranger
19 Great Deals out of 533 listings starting at $6,500
Used Chevrolet Silverado 2500HD
34 Great Deals out of 1,782 listings starting at $1,000
Used Ford F-350 Super Duty
64 Great Deals out of 1,419 listings starting at $7,283
Used GMC Sierra 2500HD
34 Great Deals out of 2,276 listings starting at $9,999

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.