Spark Plug Change Procedure
1. Obtain necessary tools:
Spark plug socket – 5/8 X 3/8 drive with rubber grip insert
10 inch extension X 3/8 drive
3/8 inch drive ratchet wrench
Torque wrench 25-250 inch pound range
Spark plug gap tool, blade style with gap adjustment feature
10 MM socket 3/8 inch drive
Tube, anti seize compound (not grease)
2. Engine must be cold. It’s an aluminum block so be careful not to strip out the threads in the plug wells. There may be some small amount of oil residue on the top portion of the plug and inside the well, this is normal.
Do one plug change at a time, There are no big spark plugs wires just a coil on plug assembly (COP) on each plug with a two wire electrical connector, a small transformer and a spring assembly (this is one unit that connects directly to the top of the spark plug)
3. Obtain your replacement spark plugs from Ford parts dealer or any FLAPS (friendly local auto parts store). I recommend Motorcraft plugs, SP505.
4. Check the gap on the plugs and regap if needed. Many times, plugs are gapped correctly at the factory. Stock gap is around .052-.056 range.
The gap is the space between the center electrode and the ground strap of the plug. The correct method is to insert the appropriate blade between the two elements and adjust the distance between the elements by bending the ground strap at its base to decrease or increase the gap.
The gap will be correct if the blade barely drags on the elements as you slide it between them.
5. Set your torque wrench to 132-156 inch pounds, (that’s 11-13 foot lbs).
6. put a very small amount of anti seize compound completely around the threads, do not put compound on the tip of the plug.
1. Remove the COP covers on each bank of cylinders. This is the flat metal cover on top of the larger valve covers. Two 10MM bolts hold this on. There is an opening on the rear for the plug control wires, so don’t reverse the COP covers. They also have a small gasket embedded in a groove.
2. This will now expose the COPs. You will only see the top portion at this time. Remove the electrical connector by depressing the tang on the plastic body. Do not break this connector tang.
3. Remove the COP by pulling straight up, this may take a little effort since the spring is a friction fit over the top of the plug. Use two hands, one to hold the COP body and the other to pull up on the spring assembly. Try not to stretch the spring assembly.
4. Fit your 3/8 ratchet, 10 inch extension and 5/8 inch socket together. Place this string into the well and over the spark plug. Feel that the socket has engaged the plug and loosen the plug (this may take a few sharp blows with your palm to “break loose” the plug.
Maintain a firm downward pressure on the tool string to keep from stripping the socket or plug and remove the plug. There may be some points where the plug is harder to turn but keep the pressure on and continue turning until the plug is removed.
5. Inspect the plug to see if the tip is a tan color and there is no mechanical damage such as metal beads or burnt off electrode. All the plugs should be very similar in color and condition.
The plugs on #7 and #8 cylinders (closest to the firewall on the driver’s side) may be harder to break free because they get the hottest.
1. Install the prepared spark plug by fitting the plug into the socket, placing the tool string into the well and starting the plug use the ratchet, not the torque wrench, begin tightening the plug until the plug is snug.
2. Replace the ratchet with the torque wrench and commence tightening until the wrench clicks. Do not over or under torque.
3. Replace the COP by positioning the spring assembly over the spark plug on push down until you feel that the spring is firmly gripping the spark plug.
4. Reconnect the electrical connector making sure the tang clicks on the COP side of the connection.
5. Repeat until all the plugs are changed.
6. Reinstall the COP covers (both banks).
7. Start engine and listen for smooth idle, test drive car after warm up and listen/feel by seat of pants for misfires. Go to wide open throttle (passing gear) on an open highway and listen/ feel for misfires. Don’t need to get to a high speed, less than 75 MPH will do.
You are done.
Regards,
Pat