1999 Ford F-150: misfire or rough idle

Filed Mar 22, 2011 · Engine · 141,000 miles · MO

While driving 45mph on suburban two lane highway I heard a loud bang and subsequent rhythmic popping sound accompanied by an engine misfiring. Upon inspection I found the # 4 cylinder spark plug lying on the valve cover; un attached to the cylinder head. The mechanic found the threads "blown out" of the head and had to utilize a heli-coil kit to repair. The spark plug was a motorcraft original equipment part. This seems to be a prevalent problem with the triton 5.4 liter engine. I suspect the problem originating from undue stress fractures in the aluminum head after continued use and inherent thermal differential rates (expansions/contractions) of the two different metals; I.e. Steel spark plug vs. Aluminum alloy head. Poor engineering !! I am the original owner of the f150 with 140k miles.

Filed Aug 22, 2008 · Engine · 124,240 miles · PA

Had just pulled out from intersection onto main road when truck developed a severe misfire. I pulled over immediately and upon inspection found the third spark plug on the right side had blown out of the hole. We took it to a garage less than a block away and they were able to install a new plug and coil pack but some of the threads in the head had been damaged. We were told they didn't know how long it would hold. Old parts are not available. I understand this is a problem on the ford triton engines and think a recall should be issued .thank you

Filed Sep 14, 2005 · Engine · 45,000 miles · AK

Manufacturing defect - plug thread failure vehicle is a 1999 ford f-150 4x with 5.4l triton and approx. 45,000 miles. While unaggressively accellerating at normal highway speeds the engine lost power and a loud popping sound could be heard. The vehicle was immediately pulled to the side of the highway, turned off, and towed to a repair facility. No injury or crash occurred. Investigation indicated a spark plug and coil had been ejected from the head. The plug was the 2nd from the front on passenger side. The threads in the head were stripped such that a new spark plug could not be seated. A helicoil was installed for approx. $300 and loss of vehicle for a week, but it failed after approximately 3 months. This failure was evidenced by engine misfire, power loss and sluggishness. Investigation revealed that same plug was not firing, and was not able to be removed because the helicoil threads were also stripped. The head was replaced at a cost of $3,626 with and additional 2 weeks lost vehicle use (2 comparable quotes from reputable auto repair providers were obtained). Repair time was longer than usual as the part had to be ordered from out-of-state and expedited shipping was deemed too expensive. At this time, however, the engine misfires continuously at idle and frequently at highway speeds. The vehicle is currently in the shop for a 3rd time to investigate this continuing condition.

Filed Oct 7, 2004 · Engine · 110,835 miles · CO

I take good care of my pickup however it has broken down on me. It began with a small shutter. It felt like the pickup was having issues idling/accelerating. Only at low (5-10 MPH) speeds did I feel the weakness/shutter. I had this issue for about 4 months, I just assumed it needed a tune up and was prepared to have one done soon. I was towing a trailer (started off fine) then at a stop sign felt that the engine was now shuttering/misfiring even more. Took the pickup to mechanic the next day and found that valve 4 was stuck open and had essentially melted its self open. This in turn caused the piston to get damaged and now I'm faced with replacing the heads or the entire engine. My pickup has 110,000 however (according to the mechanic) there have been other pickups have the same issue with as little as 80,000 miles. I have not been able to find a recall on what I've experienced.

Filed Jun 18, 2004 · Body, Engine · CA

My f150 p.u. Has a stress crack in the curve of the door by the window. The latch is not tight enough, so the door is hard to shut. My windshield wipers turn on by themselves, the odometer light goes on & off, the seat belts do not recoil & the "door ajar" light gets stuck, eventhough all doors are reshut. Engine sometimes runs rough eventhough has just had 60,000 mile check. The ford dealership wants to charge me for new part to fix odometer light $300+plus labor, $58 for door part+labor. Haven't talked to them about "rough running", I'm sure they'll want more $$ to fix it too.

Filed Jul 11, 2002 · Brakes, Electrical · FL

Truck was unstable with cause unknown by dealership. Owner has taken vehicle in for corrective action several times, however nothing has changed. Vehicle vibrates excessively when at idle with RPM gauge fluctuating up/down. *ak consumer states that the engine runs rough, oil level dropped and there was a clicking noise in which the dealer replaced the fan blade and fan clutch. Rear brakes experienced grinding, dealer applied a silencer to the front and rear brake pads. Consumer has experienced several problems with the A/C and heater, problems still exists. Vehicle uses a lot of gas, idles rough and experiences small hesitation upon acceleration. Vehicle kicks into gear. Vehicle drifts to the right, while driving at higher speeds, vehicle and steering wheel vibrate. Driver side rear view mirror rattles when closing door, when everything is closed there is an outside noise, dealer resealed the windshield. When turning on the lights, the clock and A/C are delayed. There is a whining noise when turning steering wheel. Window control buttons stick at times, dealer replaced the window switch.

Filed Dec 29, 2001 · Engine · FL

Rough engine idle. Dealer checked 3x's and says it's the way ford leans the engines that causes the rough idle. They can't replace parts unless they find a bad one. They ran electrical test equipment and found nothing. I'm not the only one that has this problem.