2009 4.6 sparkplug question.

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Oct 7, 2020 | 12:30 PM

6t6merc

Thread Starter

Cargo Master

Joined: Apr 2001

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From: Vancouver

2009 4.6 sparkplug question.

I have little knowledge of these engines, but I have heard a lot about the spark plug problem.

I want to remove the plugs from a 4.6 and test the compression. (If it is relevant, the motor is the police version with under 200,000 km.)

Did Henry fix the problem by 2009, or am I in need of your advice?

Thanks, Eric

Oct 8, 2020 | 04:44 AM

JWA

Fleet Owner

Joined: Aug 2010

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From: Reynoldsburg, Ohio

In general ejected spark plugs from the Modular Motors is largely over-stated, IMHO anyway. Yes it does and has happened but it tends to happen within the first 100K miles and almost always a direct result of improper installation or failure to check spark plug torque. When replacing plugs its best to use nickel-base anti-seize and increase torque between 23-25 ft/lbs each.

I've dealt with a total of 6 E-Series with 5.4 motors, each one with well over 150K miles and not one issue with spark plugs. COP failure is also rare when using the better brands.

HTH

Oct 8, 2020 | 07:09 PM

Johnny Paycheck

Fleet Mechanic

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You have the old school 2V 4.6 then. No fussing with broken plugs like the 3V 4.6 and 5.4 were known for.

Oct 9, 2020 | 05:01 AM

JWA

Fleet Owner

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From: Reynoldsburg, Ohio

Quote:

Originally Posted by Johnny Paycheck

You have the old school 2V 4.6 then. No fussing with broken plugs like the 3V 4.6 and 5.4 were known for.

Broken 2 piece spark plugs in the 3V heads is quite a bit different from ejected spark plugs most commonly found in the earliest 2V engines. I don't recall many issues with ejected plugs in the 3V heads.

Oct 9, 2020 | 06:41 PM

6t6merc

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Cargo Master

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From: Vancouver

Maybe I have it wrong - I thought they often broke when screwed out of well-used motors. No?

Eric

Oct 10, 2020 | 05:40 AM

JWA

Fleet Owner

Joined: Aug 2010

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From: Reynoldsburg, Ohio

Quote:

Originally Posted by 6t6merc

Maybe I have it wrong - I thought they often broke when screwed out of well-used motors. No?

Eric

I don't know if your year 4.6 has the two piece plugs but typically the Modular Motor spark plugs don't present too many problems if they've been installed correctly or were changed at least at the 100K mile interval factory plugs are touted as being that long-lived. It would be helpful to you knowing whether they've been changed at some point before you came to own the vehicle.

Otherwise there is or should be a ton of great info about dealing with potential spark plug issues here on FTE or YouTube. Here's a very basic tutorial on plug removal if its on a 3v motor: