i have a 98n expedition 5.4 triton replaced timming tensoiners because it was making so much noise. replaced all the plugs and coil packs now it has a rough idle and can be felt some when on the hiway

Asked by Aug 17, 2016 at 06:38 PM about the 1998 Ford Expedition 4 Dr Eddie Bauer 4WD SUV

Question type: Maintenance & Repair

did not have rough idle before all the plugs and coil packs and timing tensioners were replaced. took it to ford they say it has low compression on driver side.

7 Answers

20,790

When replacing spark plugs it is very easy to pick up some oily dirt that can get between the gap or the gap can get closed if plug is dropped in spark plug hole. So I would remove plugs on drivers side and take another look at them.

57,735

Is the check engine light on? If so get it scanned for codes at a local auto parts store. What brand were the coils? Genuine Ford - Motorcraft is the best and some of the aftermarket stuff is crap. If a dealer says low compression on the driver's side is it possible that the cam timing is 1 tooth off?

Bob no check engine light . it ran good except for the knock from the timing chain . after replacing the chain and coil packs and plugs it now run a rough idle . used the accel super coil packs and motorcraft plugs. engine dose not have any knocks now just rough idle. checked the iac and mafs and the throttle body

also tried pulling each coil pack wire off to see if it would make a difference in the idle and all 4 did make it run a little bit rougher. just cant figure this one out

57,735

If you are sure the issue is on one side of the engine you could put 4 of the original coil packs back in on that side if you still have them. That would be a royal pain in the butt swapping them out. I personally would not have used anything Accel makes on my truck, some have good luck with Accel and others don't. Does it smooth out just above idle?

57,735

Interesting read on coil packs at the link....http://www.f150online.com/forums/v8-engines/257269-accel- super-coils-02-4-6-a.html

57,735

More reading here.....http://www.justanswer.com/ford/5lpy6-ford- mustang-gt-just-replaced-timing-chains-tensioners-chain.html

Your Answer

Expedition

Looking for a Used Expedition in your area?

CarGurus has 17,357 nationwide Expedition listings starting at $1,500.

ZIP:

Ford Expedition Experts

  • #1
    T_S_T
    Reputation
    2,180
  • #2
    Larry Sturgis
    Reputation
    1,530
  • #3
    lightGear
    Reputation
    1,050
View All

Related Models For Sale

Used Chevrolet Tahoe
838 Great Deals out of 39,681 listings starting at $1,990
Used Ford Explorer
1,101 Great Deals out of 64,046 listings starting at $1,499
Used Chevrolet Suburban
491 Great Deals out of 23,091 listings starting at $1,250
Used Ford F-150
3,159 Great Deals out of 223,305 listings starting at $1,000
Used Lincoln Navigator
88 Great Deals out of 3,585 listings starting at $2,455
Used GMC Yukon
554 Great Deals out of 18,619 listings starting at $1,950
Used Cadillac Escalade
305 Great Deals out of 11,451 listings starting at $2,500
Used Dodge Durango
360 Great Deals out of 23,629 listings starting at $1,495
Used Ford F-250 Super Duty
463 Great Deals out of 46,636 listings starting at $595
Used Chevrolet Silverado 1500
2,873 Great Deals out of 162,467 listings starting at $1,500

Used Cars For Sale

2018 Ford Expedition For Sale
2,978 listings starting at $37,418
2017 Ford Expedition For Sale
91 Great Deals out of 4,765 listings starting at $24,491
2016 Ford Expedition For Sale
92 Great Deals out of 1,532 listings starting at $22,000
2015 Ford Expedition For Sale
25 Great Deals out of 801 listings starting at $19,997
2014 Ford Expedition For Sale
42 Great Deals out of 917 listings starting at $10,000

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.