火花塞模块化是一个反复出现的问题V8, in particular the SOHC engines with three valves per cylinder. In the 11th-gen F-150, this is the 5.4-liter derivative. Spark-plug replacement intervals are 100,000 miles, but they tend to become stuck in the cylinder head before that mileage and can be very difficult to get out. They may break and pieces of spark plug may remain behind in the head or might fall into the cylinder when this happens. The relatively shallow spark-plug thread may also become damaged. Some owners just loosen and tighten the spark plugs every few years to avoid the problem. Champion claims to make a one-piece spark plug that avoids the problem altogether but these are significantly more expensive. The 4.6-liter V8 with two valves per cylinder in the other 11th-gen F-150s may also occasionally suffer from stuck spark plugs, but it seems to be a lot less common than on the three-valve engines. Like the V6, the modular V8 can also spit out a spark plug, damaging the thread in the process and requiring thread repair and new thread inserts. Lastly, ignition coils don't always last very long and will cause misfiring when they fail. Failed ignition coils are responsible for many of the 2004-2008 Ford F-150's idle and acceleration problems.
模块化的V8的定时链很耐用,should last at least 150,000 miles if you replace the oil on schedule. However, it is important to stick to the correct viscosity of engine oil, because using too-thin oil will cause the chain tensioner to build pressure too slowly, leading to chain slap on startup and possible damage to the chain guides. Listen for any chain rattles, especially on a cold start. A too-slack chain can cause poor running and P0300 (misfire) error codes and is the cause of various 2004-2008 Ford F-150 engine/motor, misfire, timing, vibration, starting, surging, and stalling problems. Cam phasers may also give up the ghost and can either be replaced or locked out, but the loss of the variable valve timing by locking them out will have an effect on drivability. Ford F-150 oil-pressure problems may crop up from time to time, usually announced by the oil light - which should never be ignored. There is also a handy oil-pressure gauge that you can keep an eye on. If the oil pressure drops, stop before damage can occur. Either the oil pump or just the oil-pressure sending unit can be at fault, the former potentially catastrophic and the latter not. There were never any 2004-2008 Ford F-150 motor recalls for this issue, so make sure the oil-pressure gauge registers a healthy pressure reading.
Mileage:Timing chains should last at 150,000 miles, but the tensioners and chain guides may fail sooner. The spark plugs in the three-valve 5.4 engine might get stuck well before 100,000 miles. The average mileage for spark plugs popping out is around 113,000 miles.
Cost:The timing chain, chain guides, and tensioner cost around $400, plus $500 for fitment. The labor to remove broken spark plugs from the cylinder head, repair threads, and remove broken pieces from the engine may add up to many hours. The average repair cost incurred on this problem by hundreds of owners work out to between $500 and $1,210. The one-piece Champion spark plugs that should not become stuck can cost close to $200 for a set. A thread-repair kit for the spark plugs will run to a little over $200. A set of ignition coils for the V8 engine costs between $135 and $170. Replacing an engine due to engine failure may cost between $6,000 and $7,000.
How to spot:Timing chains rattle and knock when problems arise and may trigger P0300 codes and the Check Engine light. The engine might run poorly too. Ignoring the low oil-pressure warning light will soon lead to knocking sounds, overheating, and terminal engine damage. Tired coils and coil wires will cause misfires and P0300 codes, as well as poor running and performance.