Replace Ignition Wires on a Land Rover Discovery II

If you’ve ever had to replace ignition wires on a Land Rover Discovery II, you’re probably already of the opinion that whoever designed the placement of the ignition coils should be dipped in honey and thrown to the bears. We may never know what possessed Land Rover engineers to put the coil packs on the back of the manifold, facing the firewall, with an inch or so of clearance, but it’s caused plenty of grief for owners of early 2000’s Discovery II’s.

The general consensus, at least from Land Rover, is that the correct procedure for replacing ignition wires is to remove the upper intake manifold, dismount the coil packs, replace the wires, and then reverse. For ignition wires. So… they took something that should have been about a 15 minute quick fix (less if you’re only replacing the wires, but why replace the wires and not the spark plugs?) and turned it into an epic nightmare. Really? You want us to remove the top of the engine to change a wire that just snaps into place?

Well, I’m here to tell you that you can replace the ignition wires without removing the upper intake manifold, or dismounting the coil packs, or, in fact, removing anything. I’ve done it. Twice (because I bought cheap wires the first time). You’ll probably need to remove one wiring harness from its clips just to give your fingers a little extra wiggle room when you reach behind there, but that’s about it. This can be frustrating, but it’s do-able if you throw enough attitude at it.

Before we even start, and just so you know, I’m not some little guy with tiny hands. I’m 6 feet and 4 inches tall, with big hands. The point is, if I can do it, you can do it. Read through this guide a few times and think through what you’re going to be doing, and you’ll do fine.

1) Disconnect Battery

Yeah, this one should go without saying. But I’m saying it, just in case. Don’t come back whining to me if you get zapped because you forgot to disconnect the battery.

Look folks, this is car repair 101. Disconnecting the battery should always be the first thing you do whenever you’re fiddling around with electrical wiring. If you don’t, and you get zapped, your penalty is to walk around singing “Battery” by Metallica for the rest of the day (you’ll be so jacked up from the zap that you’ll probably want to).

2) Remove Wires from Coil Packs

The first thing you should do is take that wiring harness you see in the photo to the left and remove it from it’s clips so you can push it up a bit. That gives you a little extra room back in that hole you’re going to be sticking your hand in. Take a good look at the photo. See that black wire in the center of the photo behind the upper intake manifold? That’s an ignition wire. That hole is where your hands are going.

You can use whatever method works for you, but the best way I’ve found to get those damned wires off of the coil packs is to use a long screw driver and feel for the ignition wire boots with your fingers. Trust me, unless you’re double-jointed, you won’t be able to simultaneously see where the wires connect and get your screw driver back there. Of course, if you have super-human hand strength, you can try just snapping the wires out of their sockets on the coil packs with your fingers, but this is unlikely.

Okay. Let’s orient ourselves. The photo to the left is one of the coil packs, taken by holding a camera over the area and taking a picture. This is just for reference, so you’ll know what you’re feeling with your fingertips when you reach back in there. You won’t be able to see what you’re doing, so you’ll have to feel your way along. And keep close attention on what you’re doing when you remove the wires. If you snap one of these plugs off at the boot, you’ll have a hell of time getting it out of the coil pack.

The best way I’ve found to get these wires out is to use a long screwdriver. Put the tip right at the point where the wire joins the boot, in the crook of the “L” shape. Once you get the screwdriver in the right place, it’s not that hard to pop out the boot from the coil pack. Just turn the wire until the “L” of the boot is facing upwards (that helps), put your screwdriver into the crook (you’ll need to hold it in place), and gently pop it out. Patience and perseverance wins the day here. Like I said, if you snap the wire out of the boot, you’re screwed. You can still get it out of the coil pack (I’ve done it), but it’s not going to help your overall attitude.

Once all the wires are disconnected from the coil packs, it’s a breeze to remove them from the spark plugs. You can approach this however you like. I prefer to disconnect each wire, one at a time, from the coil pack, then snake it out and remove it from the spark plug and set it aside. If you do it like this, you won’t wind up with a mess of tangled wires behind the intake manifold. Also, each wire you completely remove makes it easier to get to the next one.

3) Replace Spark Plugs

This is entirely up to you, of course. But if you’re replacing the ignition wires, you might as well replace the spark plugs. If you haven’t replaced the spark plugs on the Land Rover Discovery II before, you’ll realize fairly quickly that the plugs on the passenger side are easier to get to than those on the driver side, but none of them are any real trouble.

If you’re replacing the spark plugs, go ahead and change them all out, one by one. Doing them individually will keep mayhem from getting into your engine.

4) Install New Ignition Wires

This is where we separate the grown-ups from the kids. I was going to say “the men from the boys”, but women can do this just as easily as men. Maybe even more so, since their hands tend to be smaller. If you wind up cursing a lot (like I did), this is where the cursing will begin.

I’m not trying to discourage you, but rather prepare you for frustration. You will curse. You will fuss. You will grumble and groan. Because I am hard you will not like me. But the more you hate me the more you will learn. I am hard but I am fair.

The secret here is just to keep wailing on it. What I’ve learned is that it almost always seems like when you have tried and tried to get the boot of an ignition wire to slip into its slot on a coil pack, a dozen different times at least, that’s about when it’ll pop into place, seemingly of its own accord, just as you’re about to throw up your hands in frustration. Keep having at it, and you’ll get it. And if you get frustrated, take a break and walk around a bit, cursing under your breath. That’s always seems to work for me.

With the wires are off the coil packs, you can reach behind and easily feel each socket. It helps to feel back there and run your fingers over the sockets, getting a feel for where everything is at.

Use the handy coil pack guide that’s included in the Land Rover RAVE manual, or a printable version I’ve included. This is your Bible for the remainder of the project. I’d recommend printing it out and having it with you when you re-install the ignition wires. Just keep in mind that the way this image is oriented is like it’s facing the firewall, like you’re inside the firewall looking directly at the coil packs. So what is upper left on the diagram (the slot for ignition wire #1) will actually be on the upper right when you’re reaching across the engine from behind the coil packs, feeling your way along and cursing like a sailor. It can be a bit tricksie to wrap your brain around at first. Just take your time, refer to the diagram, and make sure you’re getting the right wires in the right slots. It won’t be funny if you mix ’em up.

The photo to the left illustrates a good hand position for seating the wires. Remember, you’re basically sticking your hand into a hole trying to seat the boot into a socket which you cannot see. If you put the boot of the ignition wire between your fingers as shown, you can reach your hand down into the space behind the upper intake manifold, and even hold the other end of the wire with your other hand to help control the wire. It’s not as hard as it sounds like. Once you get the boot to set in the correct socket on the coil pack, you can use that long screwdriver to pop it into place. Make sure you get that satisfying click as it goes into place. If the ignition wire boot isn’t properly snapped into place, all this will have been for nothing.

Do one wire at a time and keep your mind on what you’re doing. This all makes more sense in practice than it does in print. If you install the new ignition wires in the following sequence, things tend to go easier (for reasons that will become apparent). 4, 3, 7, 2, 5, 6, 1, 8.

One last tip; make sure that wire #4 is pushed down below the socket for #3 as shown in the diagram before you place wire #3. It will be impossible to swing it down below #3 once its seated. The same thing for #5 below #6. They’ll be impossible to re-position once the other wires are in place (without removing something).

5) Re-Connect Battery, Et Voila!

If all the ignition wires are in place, you can re-connect the battery and give the car a start. If the car is running like it should, you can sit behind that wheel, put your head on your sore and battered hands and have a good cry. Or you can dance around the car like a crazed gypsy. Whatever floats your boat. Either way, you can feel good knowing you’ve just done something that most people will tell you cannot be done. You’d done the impossible.

Congratulations!

Now go have a beer, a shot of whiskey or a dirty martini. You can rest easy knowing that within the next few days, the backs of your hands will turn lovely shades of yellow, green and blue. Or at least they will if you do like I do and include “Aw, hell no!” as part of your vocabulary during this epic battle. If all is well and the car is running like it should (let’s face it, this is a Land Rover – it’s never a given that you fixed the right thing), drop your socket wrench on the pavement and declare, “I’m out, bitches”. Then go rest up like the mechanically inclined playa that you are. Well done!