Spark Plug Change Instructional

[Pat]

A few of my Internet acquaintances want to attempt to change their spark plugs in their Ford's equipped with DOHC engines.

I made up an instructional and thought I would ask the membership to review it and critique the content.

[Vostok]

Make this a .doc

[Pat]

You can't open it? I have Word 2007 and that's the file extension that Bill assigned.

I have not been able to change it directly, can it be done?

Mary had to put the new file extension in the bin so I could post it.

[fastblackmerc]

Can't open the file either.

[MOTOWN]

no dice here!

[Marauderjack]

Works for me....."Word" document!!

[TooManyFords]

If you do not have Word/Office 2007 or greater, download this:

http://www.microsoft.com/downloads/e...displaylang=en

It's free.

[Chevyguy]

Yeah all you guys with 8 year old Office 2003 get with the times!!

A few comments: Overall a very good writeup

Using the torque wrench with anti-sieze may throw you off somewhat. I torque em by hand but I have a VERRRY steady mental torque wrench The Factory Torque specs are for DRY plugs.

Oil seepage from the O ring around the plug hole is somewhat undesirable. My car was 100% dry. If the seepage gets enough this can cause misfires.

The COP harness connectors love to break, add a caution about this.

Also the sealing of the coil covers needs to be addressed. Should inspect the cover gasket and replace if necessary, also add a dab of black RTV where the wire harness leads into the recess. My car was all ****ed up there by a previous entry by a Dealership mechanic. They used a giant amount of RTV glopped in there and the seal leaked and rusted up the #4 plug causing misfires.

Also add some pictures, I should have taken some when I did mine.

[Bluerauder]

You can't open it? I have Word 2007 and that's the file extension that Bill assigned.

I have not been able to change it directly, can it be done?

Mary had to put the new file extension in the bin so I could post it.

No problem for me Pat.

[RF Overlord]

Using the torque wrench with anti-sieze may throw you off somewhat. The Factory Torque specs are for DRY plugs.

^^^what Chevyguy said^^^

If you use anti-seize, that reduces friction on the threads so you have to reduce the setting on the torque wrench by about 10% to compensate. Factory spec is 11 ft/lbs (132 in/lbs) so a setting of 10 ft/lbs (120 in/lbs) would be correct when using anti-seize.

Although it may seem counter-intuitive, it is better to slightly under-tighten the plugs in aluminium heads than to over-tighten them. The steel shells of the plugs can cause galling and/or distortion of the threads leading to thread failure. Over-tightening is the leading cause of the spark plug blow-outs that are so common with modular motors.

[Marauderjack]

Oil seepage from the O ring around the plug hole is somewhat undesirable. My car was 100% dry. If the seepage gets enough this can cause misfires.

Oil in the plug tubes will not cause a misfire.....oil does not conduct electricity!!

My #8 tube has been leaking a little for the last few years and I git about 1/2" between plug changes and never have had a misfire!!

[Blackened300a]

Spark Plug Change Procedure

Ford 4.6 DOHC

PRELIMINARY

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.

REMOVAL

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.

INSTALLATION

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

[fastblackmerc]

Spark Plug Change Procedure

Ford 4.6 DOHC

PRELIMINARY

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.

REMOVAL

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.

INSTALLATION

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

Should add to REMOVAL a step after #3..... clean out any debris found in the spark plug wells.

[Pat]

Thanks men for your comments, I will incorporte them in my orginal document.

Thanks John (TMF) for the pointer of Word free download to coverrt .DOCX to .DOC and to Blackened 300A for the text. Now we can all see it.

[whd507]

I would add to put some di-electric grease in the coil boots where they go over the end of the plug. I see a lot of engines with sunken plugs get moisture trapped in the bores, causing misfires, even with new plugs and boots. I sell plugs all day, I see thousands of folks in a year and while many people think its a sales gimmick to get another $1.29 out of them, but I have never had anyone complain after using it, I have had a lot of folks with unsolvable light misfires finally give in and use it to find the misfire go away. exposed plugs can dry out, but our plugs and most new cars with deep wells, keep that moisture in there quite well. as is often seen on our cars in the last bores closest to where the harness enters the covers in back.