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Spark Plugs and Wires
Ford Taurus
Mercury Sable

What is the best way to change the rear spark plugs on a Ford Taurus 3.0 DOHC?


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December 06, 2011 10:22PM

It is not hard, Many say they can do it without removing the upper Intake or plenum as I will call it but I found removing the plenum takes about 15 minutes at most and made access to the plugs much easier.

First Remove the EGR valve on the front of the plenum right behind the Throttle body. All it takes is a 10MM socket to remove 2 nuts and 2 bolts. Get some new Gaskets for the EGR valve. You can probably get by just removing the 2 upper bolts but I found things are easier if you just get it out of the way.

Then go to the passenger side of the plenum. There is a vacuum switch that you just pull the hoses off and disconnect the electrical wires that go to it. Now you can remove the plenum.

Use an 8MM socket to remove the 8 easily accessed bolts that hold the plenum on. Now you can rotate the plenum up and towards the drivers side to get the clearance for the rear plugs, You don't need much. I believe that the gasket is part of the plenum and it is reusable.

Change the plugs and put it all back together.

Watch out for the Vacuum hose under the Plenum near the Throttle body, it will probably come off when you lift the plenum up and you really can't see it. It will cause a misfire and set DTC's P1131 and P1151(O2 sensor lean). I ended pulling the plenum twice before I found that hose. If it wasn't for that hose coming loose the job would have took me less then 45 minutes. Pretty easy job just pull the plenum and make your life easy.

If you have a Vulcan 12 valve engine, the spark plugs are accessible by reaching around behind the engine from the driver's side.

If you have a 24 valve, the easiest way is to remove the upper intake manifold. I have done this without removing it, by tediously removing the ignition coil, which is held on with three 10mm bolts, and then using whatever combination of three inch and six inch socket extensions to access the plugs, but that is an aggravating way to do it. The best way is unbolt the manifold, suspend it with a bungee cord, and access your plugs.

General instructions for replacing spark plug wires:

To Remove:
  1. Label each spark plug wire and make a note of its routing.
  2. Starting with the longest wire, disconnect the spark plug wire from the spark plug and then from the coil pack.
  3. Disconnect the ignition wire from the coil pack by squeezing the locking tabs and twisting while pulling upward.

To install:

  1. If replacing the spark plug wires, match the old wire with an appropriately sized wire in the new set.
  2. Lubricate the boots and terminals with dielectric grease and install the wire on the coil pack. Make sure the wire snaps into place.
  3. Route the wire in the exact path as the original and connect the wire to the spark plug.
  4. Repeat the process for each remaining wire, working from the longest wire to the shortest.

This is a fun one. Either the engine has to be rolled forward or you have to take the intake apart to get to them and still need long skinny arms. I would pay to have it done. It's not too expensive.

There is no easy way, period. The front plugs are out in the open, but the back plugs are under the upper intake manifold. I have tried removing the coil from the rear valve cover to get more room. I've tried working every combination of extension down into the tiny little room there is, and I still find it easier to remove the upper intake manifold, and hold it up out of my way with a bungee cord.

i have 02 sable with same engine. im changing my plugs as well. ive replaced the back pressure sensor, coolant temp sensor, all within the same week. ford is not my fav make. esp since it has been designed shade tree mechanic unfriendly.

I agree with you so much. The Chilton and Haynes books on Taurus and Sables 1996 to 2005 are not much help. The 3.0L Duratec DOHC engine and the 3.0L OHV engine are very different the books cover each barely. Haynes and Chilton are now the same publishing group. Information is harder to get.

Duratec motor? If so, remove the upper intake manifold.

Vulcan motor? Should be able to do it with minimal dexterity and no other dis-assembly required.

The front spark plugs, cylinder number 4-6 are easy, since they are i the open, but the rear spark plugs, cylinder numbers 1-3 are under the intake manifold plenum assembly. It will be necessary to remove the upper intake manifold to gain access and replace the rear spark plugs. You have to take off the intake to reach them.

Well if you can't see them when you open the hood you probably have a 24 valve engine. 1,2,3 are under intake. You can still get to them pretty easy. Go to they show you what tools to use and how to replace plugs with photos, plus it's free and they don't try to sell you anything.

Pull coils off which are directly attached to each spark plug as there are no plug wires or distributor. Plugs are fired directly by computer; use rubber lined socket and when reinstalling take a 1 foot long piece of rubber hose that fits snugly on top post of spark plug to restart in threads in head.Make sure you do not cross thread when installing. Also--- prior to removing plugs always blow out wells where spark plugs are to prevent accumulated dirt from falling into cylinder when removing plugs.

You have to remove the coil pack that is located on top of the spark plug. When you unbolt the coil pack it will move to the side to give you enough room to get the spark plug wrench on the plug. Unscrew the plug and after setting the gap on the new plug reverse the process.


you want to be careful doing this. To get the best position on the back plugs you need to take the upper intake manifold off... should have six bolts. carefully remove those. next take off your air intake hose that's attached to the throttle body. This allows you to move the intake out of the way better. Then locate the EGR valve and all you have to do is remove the two bottom nuts which i think are 10mm. Okay, now you should be able to get to those spark plugs. Once you have all those put in you need to look to make sure that when u pulled the intake manifold off that no hoses came detached. There is one right under the throttle body towards the back that tends to come off when you lift it up. If when you start your car and you hear a whistling noise, then you know that a hose popped off so just be careful and double check to make sure you tighten and reconnect everything.

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