Thanks for the awesome information guys! I replaced my wires (STI) and plugs (Champion double plat) yesterday on my 2004 Disco w/ SAI. I spoke with a mechanic from a local independent (where I buy my parts) and he gave me advice if pulling the IM plenum - mostly to watch out for the little pins that hold the plenum onto the top of the IM in that they sometimes stick to the plenum and fall out - sometimes entering the IM and going into your motor.

Needless to say, I wanted to try this method. I have big meat hooks, but am otherwise pretty mechanically inclined. I was a Maytag Service Tech for a time, so I'm use to working in tight places. My head feels pretty big as I accomplished the job in 3 hours ... that's with a quick run to Ace for a 10mm socket (lost mine), dinner, and multiple questions from a 4-yr old who "helped me" the whole time! Attached picture shows my "bed" I made for laying across the engine to reach the back.

Oh ... and I made the bent screwdriver, but couldn't figure out how to properly use it. I'm sure it's something on my behalf as everyone else here figured it out. I ended up prying the wires from the coil with a long straight screwdriver and a small pry bar. Lucky No. 7 was the worse!

 

Thanks all for te great info and pictures. I was able to install new Powerstar plugs from Multispark...wow the difference is noticeable!
My only trouble was a coil pack. very hard to remove...had the shop do it
Cheers, Jim

 

That's because your old plugs were shot. Not because you spent too much money on snake oil. A set of Champions for $1 each would have made the same difference.

 

Why did the shop have to remove your coil pack?

 

Finished my plugs and wires today, one thought, it took maybe 15 extra minutes to remove and reinstall the hood and made the job so much easier. With the hood off, you can kneel on the edge of the truck and balance with one hand on the IM and reach the coil with the other. I found the top row of the coil to be especially tricky and don't know how I would have got the plugs positioned on without the screwdriver.

 

Excellent!!,.... I just saved $1,500dlls by doing this myself!!

 

Changed plugs (Bosch Platinum +4s) and leads (8MM cores) yesterday. Took about 4 hours with breaks. Used a simplified process based loosely on the original posting, and others. Essentially, I just loosened the metal pipe behind the inlet manifold (on top of the coils) by removing the clamps to the rubber pipes on each end, and loosened/pulled-off several of the ancilliary components on either end to gain access and ensure that the metal pipe was loose enough to get my hands around it.

All told a huge saving in money of course, and took less time chronologically that if I'd dropped it off at a dealer or other repair shop. Satisfied. Now, what other jobs can I take-on?

 

Great thread, getting ready to do this shortly and the information here is gold.

I see almost everyone uses 8mm, but Atlantic British has 7mm for the Discovery II. Is there a reason to use 8mm over 7mm?

It also seems a lot of folks use the +4's, yet in several other threads I've read that regular copper plugs are equal (or better, which I admit is a bit surprising). Any insights?

Thanks!

 

I like the coppers just make sure they are gaped properly....

 

Very helpful, probably saved me $1500. Two clarifications. When you say to remove the wiring harness, I could only remove it from the retaining clips and that was sufficient to do the rest of the job. I would take some pics on your camera phone of how that aluminum pipe needs to be reinstalled. It took me about 4 tries to get it threaded through the other pipes and wires right. Otherwise outstanding and clear. Thanks.