Problem Please Help
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Freshman User
Joined: Jan 2008
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Problem Please Help
Hello,
I have a 2005 F150 FX4 5.4 3v, 95k miles
I have had an ongoing problem with a misfire and what can best be described as a bogging down when downshifting. The misfire comes generally after going up a hill and the truck shifting into OD it will start to shutter and the check engine light will flash. The down shifting bog will occur when going uphill if i keep the pedal consistant the truck will downshift and then bog down and then come back out of it.
What i have done so far in order: Changed all plugs, all COPs, all injectors, dealer reflashed PCM, changed both cam phasers, new timing chain guard and tensioner (as they were broken), both timing chains and gear.
I have run out of ideas and common issues. If anyone has an idea or insight please help.
I have a 2005 F150 FX4 5.4 3v, 95k miles
I have had an ongoing problem with a misfire and what can best be described as a bogging down when downshifting. The misfire comes generally after going up a hill and the truck shifting into OD it will start to shutter and the check engine light will flash. The down shifting bog will occur when going uphill if i keep the pedal consistant the truck will downshift and then bog down and then come back out of it.
What i have done so far in order: Changed all plugs, all COPs, all injectors, dealer reflashed PCM, changed both cam phasers, new timing chain guard and tensioner (as they were broken), both timing chains and gear.
I have run out of ideas and common issues. If anyone has an idea or insight please help.
Postmaster
Joined: Nov 2006
Posts: 2,807
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From: The Woodlands, TX
Are you throwing any codes. Sometimes the COP's have issues seating and if you move them around to different positions to see if the misfire changes bank's etc. Then you can replace that COP.
What plugs did you use when you replaced them. Did you break any of the old plugs upon removal?
Hopefully this will get you thinking and someone else will be able to add some more advice.
What plugs did you use when you replaced them. Did you break any of the old plugs upon removal?
Hopefully this will get you thinking and someone else will be able to add some more advice.
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Freshman User
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all of the COPs are new and have been moved around. the misfire has stuck mostly to cylinder 5 when it occurs sometimes it is a general misfire. One plug did break. I'm losing my mind and emptying my wallet.
Sick 'n Tired
Joined: May 2006
Posts: 2,969
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From: League City, TX
Are you able to get the codes or have you been relying on the dealership? Given that you've essentially replaced the top of the engine, I'd turn my focus to the exhaust side. Look for emissions codes that indicate a bank 2 cat insufficiency, clogged muffler, bad exhaust sensors etc.
Elder User
Joined: Dec 2007
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From: Michigan
A friend of mine was having misfires on his 06. After changing all the plugs and coils, still had the same problem. Turned out he had toasted the cats due to the misfires.. I agree with Bridge, sounds like the cats are toast. Can you look at any PIDS on the Predator? Look at the HEGO's and see if they are functioning the same..
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Freshman User
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So the misfires can toast the cats, then the toasted cats can cause more? I will have my mech check the cats.
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Sick 'n Tired
Joined: May 2006
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From: League City, TX
If your cats are toast you will hear a lot of loud misfires at WOT and a great deal of hesitation and surging. You should also have a cat insufficiency code on bank 2 (the one #5 cylinder is on). Your predator might not be showing all relevant or pending codes.
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Freshman User
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A new strange development before we tore things apart the misfire was one cyl5 or a general misfire. now that its back together the misfire is on cyl3(which i beleive is the plug that was broken on removal). First thought of course would be that a coil was bad, unlikely as they are all new. just like when it was on cyl5 switching the coils around didnt make a difference. I would think that means its not a cat or that both cats are bad. FML
Elder User
Joined: Feb 2007
Posts: 866
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From: Michigan
I had the same problem after a spark plug change. Except I had a cylinder 7 misfire. They tore the motor apart thinking it was the cam phaser. Well it wasnt that so he didnt charge me. He took my programmer out and said it was worse. So he put 8 brand new motorcraft plugs in and it ran great after that. The plugs that the guy first put in were Autolite Double Platinum. If you dont have motorcraft plugs try that. I know it worked for me.
Sick 'n Tired
Joined: May 2006
Posts: 2,969
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From: League City, TX
Definitely make sure you're using the correct motocraft plugs. Especially if you got them from Autozone/orelilly's, etc. For a while their systems were suggesting the wrong plugs (SP507 vs SP462, the 507 is the correct one). Go to motorcraft's website and see which is for your rig. Also, if the one cat is toast you will get a "wandering misfire" on the affected bank. If it's both cats the misfire codes will occur in both banks.
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Freshman User
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If it turns out that the other shop just put the wrong plugs in and i have thrown over $1000 at this thing since i just might freak out. But i really do appreciate the input.
I was reading some other posts on here debating about the "right" plugs and looked it up using motorcraft.com but it lists two. SP-515 & SP507 can anyone tell me the difference?
I was reading some other posts on here debating about the "right" plugs and looked it up using motorcraft.com but it lists two. SP-515 & SP507 can anyone tell me the difference?
Sick 'n Tired
Joined: May 2006
Posts: 2,969
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From: League City, TX
SP-515 is the plug for the 6.8L 10 cylinder models according to motorcrafts website. However, they are listed for the 04 and 05 f150s. Given that motorcraft doesnt list an associated part number my guess is they've been discontinued for f150 use.
Elder User
Joined: Feb 2007
Posts: 866
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From: Michigan
Has the mechanic you took your truck to put 1000 in repairs in your truck? I know when mine was acting up the guy tore the valve cover off to repair the cam phaser and found out that was not the problem he said he cant charge me for something he didnt fix. Now I dont know if all mechanics are like that but you should see if they can work with you. I took the autolite plugs back to the first mechanic and he reimbursed me for the plugs but not the labor which was better than nothing. Maybe they can work with you.