Replace Ignition Wires on a Land Rover Discovery II

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

Disconnect the 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

Coil Packs Work Space - Insert hand hereThe 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.

Coil Packs from Above - Oh, THERE you are!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.

Close-up of ignition wires in 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

Driver Side Ignition WiresThis 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

New Ignition Wires, Sorted by Length (the peanuts were for my squirrel buddies)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 curse, this 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.

Bare Coil PackThe 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.

Coil Packs DiagramUse 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.

A Good Hand Position for Seating WiresThe 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!

Re-Connect the BatteryIf 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!

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About Wicasta

Depending upon whom you ask, Wicasta Lovelace is an author, musician, artist, web designer and/or delusional lunatic (which one he is at any given moment depends upon the day of the week, really). You can find him on Google+, Twitter and Facebook. Wicasta is working on several novels and recording music with his band, Windhaven. He is the principle editor of the Malleus Maleficarum project, lead author at PaganCentric, curator at Mama Peggy, and systems engineer at Floozees Doozees.

9 Responses to Replace Ignition Wires on a Land Rover Discovery II

  1. Jeff Addinsall February 5, 2017 at 8:29 pm #

    Thank god I found this online. Changed my plugs a week ago, purchased leads too, but left them to do later. I broke two of the old lead ends at the spark plug and pushed them back on. With this guide and a 3 inch think foam and packing blanket buffer on top of the engine, (and a good torch/led light) I completed this whole task in just over an hour. Luckily the old leads had been numbered by a previous mechanic/owner so I just had to match the lengths and replace them in the correct order and the job was done. No screwdriver needed, yes a couple of bruises on the back of my hands but I am a very happy man! Thanks for your efforts in putting this online! Jeff, Gold Coast, Australia.

  2. francisco j ruiz November 15, 2016 at 12:27 am #

    What if I just get a new coil pack, relocate it, use new wires and forget the old coil pack, leave it in place and remove old wires? Would that work or the coil pack has to be exactly where it is?

  3. Aaron Czyzewski October 8, 2016 at 10:57 pm #

    Instructions were spot on. But man, what a bitch. I took 3 hours start to finish. Didn’t use any tools on the connectors at the coil. Just a lot of hand contortion and perseverance. Wire change fixed the misfires on #1 & #8 and now the D2 runs great. Thanks for the info, Wicasta.

  4. Mark Jefferson May 10, 2016 at 12:00 pm #

    I had new plugs put in my 2004 Discovery, it ran great for about 300 miles before it gave me the code of misfiring on several cylinders and I realized I needed new wires as well. I’m not totally ignorant to auto repairs however I’m a hairstylist that is used to a blow dryer! I’m going to attempt only after this info to change them myself, every other online information instructed to dismantle lots of gear that I do not trust myself to do, until this advice, especially the patience and time involved I think I can conquer this! Will let you know, if I can do this, trust me anyone can!

  5. Paul L. October 13, 2015 at 10:10 pm #

    I just replaced the plugs and wires on my 2004 Land Rover Discovery II SE and this guide was a great help. I can attest that you want to follow his plug order it was a great help and time saver. Take your time it really won’t take long and you’ll have everything sorted quickly.

    I have recently purchased a Land Rover again after owning a discovery in Australia over 10 years ago. I got a number 4 misfire warning code and was surprised because the previous owner had only done the wires about 10,000 miles ago. They put good stuff in as well, Bosch platinum +4 and STI wires.

    When I inspected closer the number 4 wire had tape all over the plug connector (never a good sign). From what I can tell, I think someone pulled on the wire while the engine was still hot and separated the connector tab from the wire inside the cable. They tried to cover up the mistake by using tape. :(

    Fortunately for me, this happened locally, and not while I was on a road trip 8 hours from home. I was able to get some Champion spark plugs (because if I’m replacing wires, why not) and Magnecor 80242 8mm wires (British Parts of Utah). All in all it was $165 for wires and plugs and 2 hrs of time. I have the secondary air on my Disco so that added a little time. My Disco runs like a dream now and I’m hoping for a little better MPG in the future now that we are firing properly on all 8. Thanks again!

  6. Dash October 25, 2014 at 5:57 pm #

    Excellent instructions. It took me 1hr 22 min and I’m not mechanically inclined. Thank you!

  7. Damian Siekonic June 15, 2014 at 9:13 am #

    Replaced the spark plug wires on my 2004 Disco yesterday. The above instructions do indeed work, BUT……. depending on your Disco you will need to remove some of the air & coolant components to get to the coils, primarily the secondary air injection pipe, as it sits directly above and across the gap where you’d stick your hand to access the coils. And there are coolant hoses that need to be unclamped and moved out of the way in order to get the injection pipe moved. These components aren’t mentioned nor are they pictured in any of the instructions above. Fortunately this is addressed in a number of other Rover message boards as being necessary to remove if you’re going to try to replace the spark plug wires without taking off the intake manifold. Not all Discos have this feature, even same year models, and some have attributed it to emissions requirements that very from state to state. That said, once it’s out of the way, the old spark plug wires can be removed with a flat screwdriver and the new ones installed in about an hour.

  8. Derrick May 4, 2014 at 8:50 pm #

    Followed the instruction, was a little frustrating when plugging wires in order, but only because I accidentally plug them in the wrong hole bc I couldn’t see. The rest of the process was exactly how described and was not to difficult. Also I’m am a pretty tall guy with reasonable large hands and was still able to make it happen with little to no bruising or cuts. Took my time and stayed patient. Thank you again.

  9. Douglas Lee April 12, 2014 at 12:13 am #

    Thanks for your Tips. Got a Discovery 2 last week and I’m already initiating repairs to the previous owners griefs. Changing plugs and wires as general overhaul. Would like to add 2 things to your tip list I figured out when I found a rotted wire I had to replace yesterday. I wear 1 of those head flashlights for hands free manuvering. I have a small telescopic mirror to view back there and something from my construction toolkit ; a small flatbar that I can reach back carefully to apply pressure to push the boot on the coil (yes till I hear that click ). works real good. you have a great many tips that I will use though to replace the whole smazolly,
    Thank-you Douglas Lee

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