Can anyone offer any advice regarding spark plugs, coil pack and spark plugs wires on a 1998 Montero V6 3.5 liter? I’m considering doing it myself, but I’m getting cold feet because the intake manifold must be removed to do so and I’m not sure I’m up to the task. I’d appreciate any honest advice. Thanks everyone.

 

I recently changed the spark plugs on my Montero 2003 3,8. I bought Denso TT which is supposed to last over 100k miles, The intake manifold plenum is a bit of work to take off but just mark it what connects where before you dissamble or better yet take photos beforehand. Long lasting spark plugs are the way to go and also change plug wires and coil boots. I didnt bother changing the coil packs because they can be replaced without removing the intake manifold plenum.

 

Be very gentle with the Plenum bolts, these bolts only need like 13 Ft-Lbs of torque, if you strip the threads in the intake manifold, you'll have more work to do. I used NGK brand wires, coils, and Iridium plugs, I haven't had any issues in 50K+ miles. Take pictures of the top end of the engine from at least 3 angles, makes it so much easier to locate where cables/lines go if you forget. As soon as you remove the plenum, stuff some shop rags into the intake manifold to prevent things from falling down into the engine/top of the valves. Get a piece of cardboard, each time you remove a plenum bolt, punch a hole in the carboard and basically make a diagram of where they each go and shove the bolt in it, those plenum bolts have different lengths for each hole, so it's critical they go back in the right spot. Every time you remove a bolt, put it in a zip lock bag and name the bag after what the bolts go to, this way you don't have bolts everywhere and you know where they go when you go to put it all back together. Make sure you are as comfortable as possible too, if it's hot get a big fan on you, cold, put a heater on you, being comfortable is so overlooked when doing this kind of work, helps keep a level head and is more pleasant.

 

Thanks you both very much for the excellent advice. I greatly appreciate it.