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I swapped coils...plugs...from cylinder to cylinder, warrantied one plug out from a non firing cylinder, narrowed it down to only one bank misfiring. Warrantied out 3 more plugs, issue fixed. My tech thinks one 4 pack of plugs got beaten up, maybe dropped, who knows, but I had 4 DEFECTIVE motorcraft spark plugs.
Nope, no visual signs of them being bad. I had absolutely no faith in that computer telling us the plugs were faulty, but sure as ****, after replacing one a few days ago I pulled and could tell was not firing, and now replacing these other 3, runs perfect. Hasn't idled this smooth since I've bought it. Crazy rite...
how much did the cats cost you? where are you located? Arent they like $1500 a piece cdn new? I got one replaced on warranty and the shop I took it too was honest,told me my cat was plugged and said take it to ford as this part should be beyond the 5yr 60k warranty.Didnt charge me a dime. Now that shop gets all my business, knowing they are a great honest shop. and sure enough ford replaced it free! Had about 100,000km on it then. But i am thinking I may have another clogged cat. Any way to clean them? but interested to see what you paid for the parts!
how much did the cats cost you? where are you located? Arent they like $1500 a piece cdn new? I got one replaced on warranty and the shop I took it too was honest,told me my cat was plugged and said take it to ford as this part should be beyond the 5yr 60k warranty.Didnt charge me a dime. Now that shop gets all my business, knowing they are a great honest shop. and sure enough ford replaced it free! Had about 100,000km on it then. But i am thinking I may have another clogged cat. Any way to clean them? but interested to see what you paid for the parts!
Good question! Yes, they are very expensive from the dealer. I priced a set through Partsource and the quoted me $450.00 each for direct bolt-on's from Walker Exhaust. Walker also makes a weld on version for $150.00 each. I welded them on myself since I have been welding for over 30 years.
Since I have over 225,000kms (140,000 miles) I didn't even think of asking Ford for a price.
Here is what I used. http://www.walkerexhaust.com/catalog...g-lookup/93268
I teach high school auto-shop in Mississauga and I live in Etobicoke.
I work on 5.4 every day and the same prob. has had me stumped thanks for post.
Originally Posted by jdinner
bought a 2006 5.4 four months ago and it had a stumble at full throttle. I didn’t think much of it because I had planned on changing the spark plugs as soon I could. I changed the spark plugs 3.5 months later and it made no difference whatsoever. In fact, the stumble was progressively getting worse over the months. The truck has 140,000 miles and these were the first set of plugs going into it. All had broken and I had to use the Lisle tool.
Originally Posted by jdinner
I tried some injector cleaner in the fuel just as a test, no difference.
I was now getting P0300 and random specific cylinder mis-fires(P0305, P0308…).
Truck was now shaking at idle and I could only use about half throttle. After half throttle it would pop in the intake and the engine would slow down then produce a flashing engine light with more mis-fire codes.
Luckily I have my 4.6 Mustang in storage for the winter and I borrowed all 8 coils from it as a test to see if that would change anything. No change.
I tried Seafoam spray upper engine cleaner into a vacuum line as per the instructions. I let it do its thing and took it for a test drive. I was now worse. 50mph was my top speed and I could only feather the throttle. The next morning 40mph was my top speed.
I scanned the fuel pressure and then changed the fuel filter again, no change. Fuel pressure was 40psi.
I pulled all the injectors out and cleaned them one-by-one. All looked very clean with the identical two nozzle spray pattern. Reinstalled, no change. Problem is even worse now.
As a mechanic for over 30 years I was stumped. I took it to a local garage and they checked it too. They were stumped also but suggested I noid light the injector circuits. I did that and they all checked great.
Yesterday I had a truck that I could barely drive and I didn’t know what was wrong with it.
I have been pouring over this forum for two weeks trying to find a solution to my symptoms and all the threads I found did not have a ‘solved’ post. This thread does have a solved sentence!
Purely by running out of ideas I heated the exhaust pipe/manifold nuts and dropped the exhaust system down before the catalytic converters. Test drive - PERFECT POWER and really loud.
Both converters were plugged and not giving me any codes or tail pipe indications that there is/was a problem.
I’m welding in new catalytic converters today but I just thought I’d share my experience with this hair pulling process.
Dropping your exhaust costs $0.00 and is an easy check. I wish I had found a thread that had a conclusion with my symptoms.
any one seen this from a plugged up catalytic converter?
I started a new thread in the 1997-2003 since my truck is a 2002. I changed all plugs and coils and ran out of ideas until it really started to run rough. looked for a vacuum leak and found the melted manifold... any suggestions would be great.
My mechanic friend said the exhaust that is recirculated was so hot that is melted the intake. Makes sense to me but want to ask.
this is the front driver side where I had one of the High Temp Emissions Hoses came off (dissolved off) and melted a hole and a groove. I didn't see this til later due to the other stuff in the way. I fixed it and then all my other problems started. Thought I just had a gasket leak from throttle body and the top of the intake...
Last edited by BirleyG; 01-16-2017 at 09:04 PM.
Reason: adding info
I'm having the Excat same problem same year same engine
Originally Posted by jdinner
bought a 2006 5.4 four months ago and it had a stumble at full throttle. I didn’t think much of it because I had planned on changing the spark plugs as soon I could. I changed the spark plugs 3.5 months later and it made no difference whatsoever. In fact, the stumble was progressively getting worse over the months. The truck has 140,000 miles and these were the first set of plugs going into it. All had broken and I had to use the Lisle tool.
I tried some injector cleaner in the fuel just as a test, no difference.
I was now getting P0300 and random specific cylinder mis-fires(P0305, P0308…).
Truck was now shaking at idle and I could only use about half throttle. After half throttle it would pop in the intake and the engine would slow down then produce a flashing engine light with more mis-fire codes.
Luckily I have my 4.6 Mustang in storage for the winter and I borrowed all 8 coils from it as a test to see if that would change anything. No change.
I tried Seafoam spray upper engine cleaner into a vacuum line as per the instructions. I let it do its thing and took it for a test drive. I was now worse. 50mph was my top speed and I could only feather the throttle. The next morning 40mph was my top speed.
I scanned the fuel pressure and then changed the fuel filter again, no change. Fuel pressure was 40psi.
I pulled all the injectors out and cleaned them one-by-one. All looked very clean with the identical two nozzle spray pattern. Reinstalled, no change. Problem is even worse now.
As a mechanic for over 30 years I was stumped. I took it to a local garage and they checked it too. They were stumped also but suggested I noid light the injector circuits. I did that and they all checked great.
Yesterday I had a truck that I could barely drive and I didn’t know what was wrong with it.
I have been pouring over this forum for two weeks trying to find a solution to my symptoms and all the threads I found did not have a ‘solved’ post. This thread does have a solved sentence!
Purely by running out of ideas I heated the exhaust pipe/manifold nuts and dropped the exhaust system down before the catalytic converters. Test drive - PERFECT POWER and really loud.
Both converters were plugged and not giving me any codes or tail pipe indications that there is/was a problem.
I’m welding in new catalytic converters today but I just thought I’d share my experience with this hair pulling process.
Dropping your exhaust costs $0.00 and is an easy check. I wish I had found a thread that had a conclusion with my symptoms.
I'm having the Excat same problem same year same engine... Going to try this. Thanks
Hello Guys new to forum and also a Army DAV... I just purchased my 05 F150 5.4L 3v. having these same issues but my mechanic disconnected my exhaust and my truck ran the same way... awful. this is my only transprtation as it ran good 1 day, the opurchase day... what LUCK!!! and I\we've change all the above parts except catalytic converter because the truck ran the same way while disconnected. I heard the CAM phasers ??? can make it run bad ? where are they? any wisdom will help and I will record my findings. I'm a frmer Helicopter mechanic that suffered from a major back injury entering my 20th year that forced retirement. I know what EATING and RUNNING is about!
03-13-2015, 08:24 PM
