Start cussing now - get it out of the way before attempting this job! There are 3 ways to get to the back three spark plugs on a Winstar Minivan (as a reference, I'm using a 1999 Windstar with 3.8 Liter Engine with a Spark Gap of .052-.056 inches)...
1. Raise the Vehicle Up on a Lift and Remove the Passenger Side Wheel - to Gain Access Underneath.
You can reach the first (back side) spark plug from this position - Simply reach around side of the block just behind the wheel. Remove the spark plug wire by twisting and pulling on the boot at the same time. Use a 5/8" spark plug socket with rubber insulator protector to help lift the plug when it is unscrewed.
To reach the other two back plugs, you'll need to raise the vehicle all the way up. You will need to "snake your hand" through a small area just above the transmission pan leading to the back side of the block. It is tight, but there's sufficient room to maneuver a ratchet and socket. Thankfully, you'll have sight to these plugs unlike working blind from the topside. Estimated Time: 1-1/2 Hours.
2. Underhood Method Requires Removal of the Cowl - Remove the Plastic Section that Covers the Wiper Motor on the Upper Firewall. You'll need to remove the wiper arms, wiper motor assembly, washer fluid lines and the electrical connectors to the motor to gain access to the spark plugs. Once removed, you have good access to replacing all three plugs. You'll be lying across the engine plenum or intake, so get a few finder covers or blankets and make yourself comfortable. Estimated Time: 1-1/2 Hours.
3. Underhood Method Requires Removal of Throttle Body, Intake Air Tubes and Filter Assembly. Once removed, you'll have just enough room to reach around the back side of the engine on the right (driver side) to insert a spark plug socket, stubby extension and a 3/8" drive pull handle. The ratchet handle makes the wrench too fat. The left side (passenger side) is even tighter, but you can reach around and remove the first plug. Estimated Time: 1-1/2 Hours.
If you are a professional technician, Ford recommends removing the upper intake manifold. Make sure the engine is cold before you start. Keep in mind that aluminum cylinder heads can strip spark plug threads if the engine is hot during removal. Install all spark plugs by hand, making sure the threads are not crossed before tightening. Torque spark plugs to specification, this means "wrist tight" and DO NOT OVERTIGHTEN!
Have a great day and best wishes on changing your own spark plugs - HELL HAS NOT FROZEN OVER YET!
Click on the Photo to Learn How to Remove a Broken Separated Spark Plug on a Ford 5.0 Liter V-8 Engine Without Any Specialty Tools or Pulling the Head
