I was driving to work through Louisville, Ky. I was luckily not on the Interstate. I had just regained traveling speed (30MPH) after stopping for a light. I heard a loud noise that sounded like a rod knocking. I immediately pulled over and looked at my oil gauge, which read normal, I then turned off the motor. I popped the hood to investigate the damage. I looked under the hood, and at first could not see any apparent damage. I started the motor, watched the motor. That is when I noticed the coil pack on the number 5 cylinder was loose. The motor was still too hot to pull it out, so I called a tow truck and brought it home. After further inspection, I found the spark plug intact, but it was fully loosened and out of the head. The bracket of the coil pack was broken in half. I have not had any problems from this truck, aside from basic wear and tear, since I bought it in new in 04'. I do regular maintenance, and do not dog my truck. At this point I am going to have to get it in the shop, and find out how much damage was done to the head. Hopefully it is not as bad as I have heard. I will update on the out come.

Ford needs to take ownership for this issue, third time this has happened. Absolutely ridiculous the time and money to fix the spark plugs due to their poor manufacturing on the 2004 - 2008 F150 models and or the engineering design of the threads. Wake up Ford and step up to address this problem, or plan on losing a lot of loyal customers as this year Fords are spitting spark plugs like sunflower seeds, very very disappointed on Fords stance on this - considering other options for next vehicle. Keep making your commercials with washed-up Dennis Leary.... maybe focus on making a truck that works.

I drive a well maintained, easy driven 2004 F150 with a 4.6L. While driving home from work yesterday on the expressway, I was accelerating to merge into traffic (as I normally do) without any issues. I get up to speed and begin changing lanes. As I step on the gas to change lanes there is a loud pop followed by horrible sounds of exhaust popping and loss of power/acceleration. I thought I either broke a manifold or blew a converter up.

I was still able to drive it but it sounded like the motor was ready to blow up. I had no loss of oil pressure, no over heating, no smoke blowing out of exhaust, so I was wondering what could have gone wrong. I get the truck to the shoulder and get out to check the engine. I open the hood and see it right away. Passenger side, second coil back was broken in half and the top of the plug is laying on the intake. I was able to drive/limp the truck to the house and had a couple mechanic buddies come over to look at it. Both of them after start up said "Not good, looks and sounds like a blown plug".

I haven't had a chance to get it to the dealer for their expert advice, but all signs point to blown plug. Now, do I want to fix it (with 129,000 mi.) and take a chance on another one on the drivers side blowing out. Or, get rid of this problem before it drains my bank account. I do regular/routine maintenance (brakes, tires, oil changes, fuel pump, fuel pump drive module, fuel filter) and was getting ready to change plugs. But after reading threads about aluminum heads and plug problems i chose not to change them. The truck has been running fine and not having any issues. Not until.... The dreaded blown plug..

Thanks for letting me vent... Proud F-150 owner. Now pissed off F-150 owner.. Shame on you Ford for knowing about and not fixing this problem..

Spark Plug blew out several times over a year on the truck. Finally it destroyed one of the heads and it destroyed the coil. Had to remove the engine, purchase a new head, remove both heads. Had Dover Head and Cylinder in Chattanooga repair both heads with steel thread inserts. Changed the Eight new spark plugs with different plugs that have 15 threads instead of 4 threads, new gaskets, new head bolts and put engine back into the truck. Cost me around $4,000. Have receipts, pictures, old head in the garage. After the repairs still driving the truck with no problem. Ford needs to settle on a class action lawsuit.

Had the spark plug blow out of the head on me driving home from work. After seeing all of the other complaints I am wondering why the hell I even bought the truck now. I am a machinist by trade and expect better out of ford. Hate to say this but they lost my business for good and I grew up in a ford family. Will be fixing the truck and then getting rid of it ASAP and going to be looking at a GMC since ford doesn't want to acknowledge the problem and help owners fix their F*CK UP. No wonder it's always a machinist having to fix an engineers mess LOL

My name is Larry, on June 24, 2015 while driving my F-150 my #3 cyl plug blew out, had it towed to the dealer that I bought the truck from, Mark Kia of Scottsdale. ( I know, wrong place to purchase one's truck) quoted $850.00 to fix the problem because it wasn't covered under said service contract, so had it towed back to my house thinking that I could find it cheaper where I live ( wrong). Said spark plug blew through valve cover, now I have to replace the head which has now brought the price up to $1400.00. Luckly I have triple AAA free towing for up to a 100 miles, I haven't had said truck fixed due to lack of funds.

There should be a class action lawsuit brought against the Ford Motor Company about this problem !!!!!

I have been a machinist for 28 yrs and I never thought a big company like Ford would have this problem . This is clearly bad engineering. Why in the hell would you design a aluminum head and have the threads for the spark plug so weak. I did some research and this has been a problem for along time and Ford has done nothing to help owners fix it . My 2004 F150 with 4.6 v8 blew a spark plug and trashed the head, it looks like it will have to be replaced.The truck has been very good until this.

These are the factory installed plugs and it is number 3 cly. It can't be drilled and a thread repair done because it took a piece of the head out. The repair is going to be expensive and I don't know where I am going to get the money to get the work done. I cannot believe Ford is not taking any action . There needs to be a lawsuit filed so that Ford backs their product up and help all that has been affected.

Was out of state for my Dads 91st birthday when the spark plug blew out of the engine.After it was fixed it happened again 2500 miles later it welded the coil sleeve to the block.Had to put a new engine block on.2000 miles later it blew a spark plug out on the other side of the engine they put a new coil sleeve in.2100 miles later it blew another plug out and the injector let gas get in the engine where the spark plug blew out and the engine locked up.It is at Ricart Ford where I bought the piece of junk they are fighting with Fidelity Warranty Services Insurance that they sold me there if it is covered under warranty or not.$442.00 a month for a piece of junk bought at Ricart Ford in Groveport Ohio.This happens a lot with the 2004 engines and we need to get a class action suit against Ford motor company so they will have to recall the trucks so nobody else has to deal with this problem.The truck has 85,000 miles on it and have not had it 2 years yet.Ricart Ford and Ford Motor Company does not want to do anything about this problem.

On my way up the California coast into Oregon the truck spit out a spark plug. As a result the engine was rough, noisy, and lacked power. Gas fumes quickly entered the cab, but I was able to get over reasonably and call for a tow. The tow truck driver mentioned that he had seen this issue with the F150 before several times, always with the same plug and that it would be a quick fix. He didn't understand why it wasn't already a recall issue, but quick it was - about 2 hours later and the truck was ready. He had essentially re-tapped the head to insert a new spark plug and replaced the damaged ignition coil along with it. After researching the problem, I was (and am) amazed and disappointed at how common this problem is with a select few of the Ford engines.