corey_lax

It's been posted on here a few times lately that the plugs should be changed at 60,000 instead of 100,000... The plugs can last for longer than that but the earlier you change them, the less likely they are too break.

My spark plug change started two years ago at 100,000 KM (62,000 miles) and the first 2 broke. The weather turned to crap so I waiting another year to change mine at 135,000 KM (84,000 miles) and the remaining plugs all broke. So don't expect small amount of miles to completely help you out with broken plugs. Its all about a little bit of luck. I didn't have any haha

ford lover 07

Yes it a fact that they did change it to 60,000

F0rd1926

iTrader: (1)

Ive heard running a few tanks of chevron techron through it helps dissolve the carbon making the job more likely for A sucess

rockymtnrider

So I cleaned the MAF and throttle body today. This made a huge improvement. Still backfires when rev'ed but not as much and the rough idle is completely gone. The apparent rough shifting is gone now. I am waiting for the FPDM to arrive in the mail ($55 on Amazon/108 locally). How would I know if a COP was out? Wouldn't it throw a code? I will be getting the plugs done next. Thank you guys.

F0rd1926

iTrader: (1)

I didnt have any codes my would throw a blinking wrench light then go out only when it was running bad. I did the cops as a preventative measure.

VTX1800N1

Are you sure it's backfiring or could it be a loose baffle rattling around in the muffler?

ddc

I know I'm a lttle late for this thread. My truck has 63k miles, my buddy who was a Ford tech, now on his own making better money, said to let the plugs go until it starts running bad. He's tried a couple times changing them earlier and it didn't matter. Some break, some don't. Even had a friend pull his at 26k miles to put anti-sieze on them, he had 3 break off. But the backfire you are describing, does it sound more like a snap, or a crack out the exhaust? Mines done it since new if I rev it up at idle, with a flowmaster muff its real noticeable! The tranny slip, I find myself sometimes putting it in 2nd gear accidentally, then I remember with a Ford, if the stick says 2nd, its in 2nd. And it does sound as if its slipping, lugging down more than anything. Its still the best truck I've had. GMC was ok, but what a heap after a while....

rockymtnrider

Ok, so, maybe I use the term backfire a little loose. It is more of a snap or crack. It has done it since I bought it at 55k so maybe this is normal. The muffler (and tailpipe) will drip water when it's cold (normal) so it could be some rust making a hole. It stopped doing on the highway along with the bucking (what I thought was tranny slip). And I've checked the baffling, it's on tight and not rattling. My transmission is no longer in question. I haven't seen the wrench light blink at all. My little brother had a '97 5.4 that had the COPs go out and his wrench came on and it would limp along. I dodn't know if this was the same for the 2nd gen 5.4. I might change them with the plugs just in case. I am suffering from a dirty fuel/air delivery system which will result in new plugs eventually, but for now I am going to focus on cleaning out my engine. I am running a bottle of Seafoam through on less than 1/2 tank right now to see if that helps. Does anyone know where I could introduce Seafoam it into the vacuum system so that it would reach all the valves and cylinders? I saw a plugged hole just behind the MAF but I can't seem to get it off.

My spark plugs will soon be replaced thanks to the new information I have received because of this thread. That being said please don't post about how many of your plugs broke or how long it took. If I want to know I will look up the numerous other threads that talk about it. Please reply with how you cleaned your fuel and air systems and what the results were.