Ford HT1 Spark Plug Procedures
And what is involved!!!
Problem:::: Ford HT1 spark plug design from the factory is poor, it is a two piece spark plug that is pressed into its housing as opposed to machined in housing, this allows for a weak ridge along the bottom of the spark plug, with this weakness when removing spark plug from the engine the weak ridge doesn’t move but the rest of the spark plug does which causing it to break off clean. When this occurs we must take measures to remove the broken piece from the cylinder head which of course takes time… sometimes lots of time.
Course of action…. We have tried multiple methods from cleaning injectors and intake components to soaking overnight etc., the service bulletin Ford in existence today involves soaking after breaking loose spark plug and we have several methods we have found some are effective and some are not. Problem with breaking plug loose first is this is where the break first occurs.
What can be done before hand? Although there is no proven method to prevent this short of replacing spark plugs when at a very low mileage keeping intake tracts clean seem to be the best method to prevent this breakage from occurring.
What we do? In the event spark plugs break we employ a method of extraction that typically takes 1-2 hrs per spark plug depending on location. Most of the time we are successful in one hour’s time and this is what we charge per spark plug to remove. After removal we install a revised version of the spark plug made by aftermarket plug makers that has a fully machined spark plug that prevents this from reoccurring in the future.
What are the dangers??? Of course most of the time when a vehicle comes in for spark plug replacement it is due to maintenance tune up or a drivability or engine light repair, the dangers of not fixing this concern are catalytic converter damage or possible internal engine damage over time.
What risk do I take? The main risk involved with replacing plugs is breakage and removal, in extreme cases we have had to remove the cylinder head from vehicles to extract the spark plug manually from the cylinder head, if this occurs there is substantial labor increases as most of these require engine removal to gain access to cylinder head bolts. This of course is not the plan of action we would prefer to take, we take all measures to try our best to make the repairs as quickly as possible without additional repair time.
Vehicles affected::::: 2005-08 Mustang 5.4
2005-2008 Expedition and F series
2005-2008 Lincoln Trucks
2006-2008 Mercury Mountaineer.