Why are spark plugs ejecting from the cylinders?
A couple theories exist on why spark plugs in Fords are ejecting from the their cylinders. Some blame the design of the the plugs and the use of a aluminum cylinder heads. The plugs only use 4 thread which are also made out of a weaker aluminum that is subject to wearing down.
Where does the spark plug go in an engine?
The spark plug’s metal shell is screwed into the engine’s cylinder head and thus electrically grounded.
Why are spark plugs ejecting from my Triton engine?
We believe this defect affects the following 2-valve engines: Triton 4.6L V8, 5.4L V8, 6.8L V10 & possibly others. A couple theories exist on why spark plugs in Fords are ejecting from the their cylinders. Some blame the design of the the plugs and the use of a aluminum cylinder heads.
What causes a spark plug to blow out in a Ford?
A video showing spark plug thread repair using Calvan spark plug inserts being installed can be viewed on the Calvan 38900 description page. Read on for more information. Ford 4.6, 5.4 and 6.8 modular engines are prone to spark plugs being blown out of the cylinders due to the aluminum threads failing.
What happens when a spark plug blows out?
And when that happens, they just slowly work their way out and then blow–with a frighteningly loud sound. But that never strips the threads. You just screw the plug back in and everything’s fine (except for the dent on the underside of the hood made by the “launching” spark plug).
Why does my spark plug keep backing out?
The coil keeps the plug from backing out completely. The spark plug vibrates until the aluminum threads in the cylinder head are deteriorated to a point that the spark plug ejects from the pressure of the compression from the cylinder. The spark plug ejecting typically breaks the coil on the way out.
How big is the hole in a spark plug?
Calvan 38900 – Over sized kit that repairs spark plug holes up to approximately .678″ (17.24mm) which is the reamer O.D. The outside diameter of the insert is .73″.
Can a loose spark plug damage aluminum threads?
They may have accidentally stumbled upon the real area of concern though. A loose spark plug, especially one that is held in above with an ignition coil can vibrate and damage aluminum threads. It actually would do less damage if it were allowed to back on out without being held by the coil.