V10 FAQ

By: Arthur Krewat

This is a re-hash of the original FTE V10 FAQ available as a sticky post in the V10 forum. This will (should) eventually become a tech article on FTE.

Some threads from FTE that pertain to MPG:

Highway MPG poll: http://www.ford-trucks.com/forums/448486-the-official-highway-mpg-poll.html?highlight=mpg+poll

Combined MPG poll: http://www.ford-trucks.com/forums/442599-the-official-combined-mpg-poll.html?highlight=mpg+poll

Towing MPG poll: http://www.ford-trucks.com/forums/501842-the-official-towing-mpg-poll.html?highlight=mpg+poll

Power output of the V10 for all years:

2005-up 3-valve, F-series trucks:

362 hp and 457 ft/lbs.

2000-2004 F-series trucks (Superduty):

310 HP @ 4250 rpm and 425 ft/lbs @ 3250 rpm.

1999 F-series trucks (Superduty):

275 hp and 410 ft/lbs

E-series, 1997-1999:

265 hp and unknown torque

E-series, 2000-up 2-valve motor:

305 hp and 420 ft lbs

Common complaints/problems with the V10:

Spark plug blowout - Considered "common" but statistically insignificant, this was a huge PR problem for Ford. All modular motors were susceptible to this problem. Some information became available to me but because of it's legal nature, could not be discussed on FTE. I will not go into the specifics, but for now, there are a few major points:

3-4 threads were initally used for the spark plugs in the cylinder heads.
Initial Ford reaction was to change the torque procedure at the factory, apparently to reduce over- or under-torque. This was around the 2000 timeframe.
Late in the calendar-year 2000, Ford altered the head to include an "alignment feature" that reduced cross-threading or incorrect torque at the factory.
Late in the calendar-year 2002, Ford increased the number of threads in the head to approximately 7-8 threads, called "long-thread" heads.

A note about my own 2001 V10, manufactured Sept 2000: Definitely long-thread heads. So Ford's own documentation supplied during investigation into the problem is inaccurate. No concrete determination can be made as to when the long-thread heads were introduced at this time.

Many aftermarket inserts exist, Timesert being one, that cure the problem once and for all. For pre-2001 engines, it has become commonplace to recommend installing inserts on ALL 10 cylinders to avoid problems in the future, especially during an engine or head swap. The old "while you're in there" effect.

COP failures - Like all the later modular motors, the V10's use Coil-on-Plug (COP) style ignition coils. Many MANY reports have been made of changing out COPs to cure misfires. However, all the anecdotal evidence I have read points not directly at bad COPs, but moisture or boot failure, and sometimes the spark plug, as the primary cause of the misfire. Changing the COP and plug solved the problem, but the initial root-cause was either dirt/moisture in the spark plug hole, the spark plug itself, and, somewhat rarely, complete coil failure.

IAC (Idle Air Control motor) failures - When startup and idle quality issues show up, the general consensus of most of FTE's members has been to point to the IAC. Some of the time, cleaning it will cure the problem, other times it requires replacement. In rare instances, the IAC ports in the throttle body are clogged and need to be cleaned. For approximately $30-40, replacing the IAC instead of cleaning it is prudent.

PCV elbow - Some of Ford's molded rubber parts show an amazing amount of degradation in a short amount of time. Within just a year or two after manufacture, the rubber starts to deteriorate so much that rubbing your fingers on it leaves your fingers black with rubber particles. Cracking and complete failure follows rather quickly. The plumbing to the PCV valve includes a rubber 90 degree elbow that cracks and creates a vacuum leak. This can lead to idle or starting issues just like the IAC, so when recommending a cure to these issues, almost all of us immediately point to the IAC and the PCV elbow.

Flutter - This has two meanings.

One is an exhaust pulsing that happens around the 1600-2200RPM range. This happened on early pre-2001 engines, and Ford came up with a "rams horn" style y-pipe to help cure the problem, which didn't always solve it. Aftermarket exhaust systems, especially with headers and different y-pipe, greatly exacerbate the problem. Theories abound as to what causes it, but it appears to be an unequal y-pipe length on each side, causing interference between exhaust pulses at certain RPMs.
The other is an exhaust heat-shield or bellhousing inspection cover (on automatics) vibrating in the same RPM range. The inherent imbalance of the V10 causes the vibration. Removing the inspection cover and bending it, or gluing it, or using some sort of rubber strip cures that particular problem. Using hose-clamps on exhaust heat shields or welding them back on helps.

Common maintenance procedures for the V10:

Spark plug replacement on 2-valve motors:

Materials and tools required:

5/8" Spark plug socket, with rubber insert.
As many different-length extensions as possible.
Swivel-head socket wrench.
Dielectric grease
Anti-seize
Inch-pound torque wrench that can set to 14ft/lbs (168 in/lbs).
Air compressor, high-volume, 100PSI, with a long extension or rubber hose on the end of the nozzle.

Procedure:

Remove all COPs. Be careful and don't drop any bolts. They can be hard to recover from the engine valley.
Blow out all spark plug holes. This is VERY IMPORTANT. You do not want any dirt getting down into the cylinder.
Loosen all plugs 1/4-1/2 turn. Pay attention to how hard the plugs are to turn. If they are corroded into the thread, you run the risk of pulling threads out with the plug. If any plug is hard to turn, spray a penetrating oil (NOT WD40!) in the hole, allow to sit for a while, and try again.
Blow out spark plug holes again. This will remove any dirt that was stirred up by loosening the plugs.
To be very anal, loosen all plugs another full turn, and blow out holes again.
Remove all plugs. Examine plugs for fouling, aluminum in the threads, corrosion or any other problems. If any aluminum is found in the threads, consider stopping and getting a professional opinion on the problem. With an inspection mirror, look at the condition of the threads in the head. If you have a 4-thread head, seriously consider putting an insert in any hole that showed aluminum on the plug.
Check gap on replacement plugs, the spec can be found on the under-hood sticker.
Apply LIGHT amount of anti-seize to the threads of all spark plugs. Make sure none gets on the cylinder-side of the plug, but fill the threads and cover the seat of the plug.
Install plugs. Use a piece of rubber hose, or a spark-plug socket with rubber insert with the appropriate extension that holds well enough so you can pull the socket off the plug. Finger tighten ONLY, until the plug seats.
Set the torque wrench to 5-7 ft/lbs (60-84 in/lbs), and torque all plugs. When tightening them to that torque, observe how much rotation is required to reach that torque. If any plugs turn less (or more) than the others before reaching the set torque, remove the plug and examine the hole/threads for any damage or dirt. THIS IS VERY IMPORTANT. Too much rotation to reach the required torque indicates bad threads or a dirty seat. Likewise, too little rotation before reaching the desired torque indicates cross-threading, bad or dirty threads, etc. It may require chasing the threads with the correct tap.
Set torque wrench to 14ft/lbs (168 in/lbs) and re-torque all plugs again. Use the same precautions as outlined in #10.
Replace all rubber boots on COPs. There is almost no reason to re-use the old ones when replacements are available for $3-4US. You do NOT need to use Motorcraft brand boots. Coat the inside of the ends of the boot with dielectric grease on both ends. This will help keep moisture from effecting the spark. Install boot back on COP with the spring inside.
Re-install all COPs, making sure there is enough dielectric grease on the spark plug end.

Notes:

Brand-new Motorcraft replacement plugs come zinc-plated (galvanized), unlike the original stock plugs. This is a good way to determine if the plugs were ever changed.
Motorcraft specifically states that anti-sieze and dielectric grease be used.
Spark plugs on the Ford modulars should be checked periodically. At least once every two years or 30-40K miles seems to be the general consensus at FTE.
Ford's revised torque procedure for plugs at the factory is: During initial torque run-down, when torque has reached 4.3-8.6 ft/lbs, only 3-25 degrees more rotation should be needed to reach the required 11.5-14.4 ft/lbs. Hence, the procedure above, specifying first torque-down be 5-7 ft/lbs, with final being 14 ft/lbs (as recommended by Fredvon4). If more than 25 degrees of rotation is necessary to reach 14 ft/lbs, CHECK THE THREADS CAREFULLY. Likewise, at least 3 degrees of rotation should be noted, otherwise the plug is stuck in the threads or seat.

IAC replacement

The IAC motor is a silver cylinder with connector located on the back of the throttle body. Two bolts hold it on, and is easy to replace. It is harder to check if the ports are clear, using an inspection mirror is suggested.