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Ford V-10 engine

I own a ten-year-old motorhome with a Ford V-10 engine that has 47,000 miles on it. The owner’s manual recommends changing the spark plugs and anti-freeze at 100,000 miles. Considering the age of the MH, should I have the engine tuned, replace the sparkplugs and anti-freeze in the near future? Thank you.

For the spark plugs, you should at least take them out and inspect them. If for nothing else taking them out and putting them back in helps keep them from welding or seizing in the motor.

For everything else check the owners manual, I bet it has the service times in miles AND time.

Be very careful. The early Modular V8 and V10 motor are known for having spark plug issues. There are are even special thread inserts and tools for pulled out threads. I understand it s 3 hour job on the V10 SuperDuty due to coil on plug design. The antifreeze is supposed to be changed at 5 years or 100,000 miles, which ever comes first.

Step by step instructions:

More info:

I am scared to do them on my V10

Ive heard the same about this type of Ford engine having difficulties with the plugs. Do a google search…there is so much on this topic it boggles the mind.

Source: internet

  • the threads on these heads are made of aluminum and there arent enough of them to properly support the plug. Im not completely certain what years are affected since different sources quote different model years but from the 90’s to 2004 is the range Ive read.

Source: mechanic acquantaince

  • their procedure is a 3-day long process where they run cleaner (didnt get specifics) into the cylinder and also from the top and let it soak three days before they try to remove the plugs. He says the first few threads from the plugs are actually inside the cylinder and exposed to the combustion. They get coated with deposits then when an attempt is made to remove the plugs the deposits damage the cylinder head threads.

Source: acquaintance familiar with the issue that works at a car dealership:

  • basically reiterated what I already read on the internet. The heads are poorly designed and their dealership fixes them with Helicoils or something similar. Said a lot of repair shops he knows of wont even do it.

I need to change my plugs since its one of the most basic maintenance projects there is but due to a crappy design Im afraid of stripping the heads to the tune of a $3,000 repair bill. New heads for the V-10 are about $1,500 each…you’d need two.

Don’t confuse the spark plug issues on the 2V and 4V heads with the carbon issues on the 3V heads. The mechanic acquaintance narrative sounds like 3V head issues. They have a very weird spark plug to my eyes.

Most of the problems with the 2 and 4V heads are probably due to working with the heads hot and not applying the proper torque. The latter includes using the dry torque figure with anti-seize compound lubricating the threads. Some people just can’t follow directions.

There have been Modular Ford Engines 4.6 5.4 That have blown the factory inserted spark plugs out of the hole, its a poor design. Period. I agree Hot engines and improper torque can make it worse, but there is a major issue with these heads.

I hope you listened to whoever told you earlier not to replace the plugs in this engine. We have a 2000 RV with a Ford V-10. We spent $3500 having all the plugs and coils changed two years ago – terrible experience. Now, we have another similar problem and are being told we should replace the engine to the tune of $8000. Even worse!!! Hope you are not running into the same problem. Ford built a very bad design of the V10 between 1996 and 2002 and has refused to offer customers any help. Will never ever buy a Ford gasoline engine again!! Good luck.

$3500 for new coils and plugs? You got taken for a ride on that one. Aside from the spark plug ejection issue (mainly seen on the 5.4L) and piston slap (mainly seen on the very early 5.4L) The Ford modular engines are pretty reliable. The 4.6L is particularly well known for it’s reliability and good combination of power and fuel economy.