I am going to change the 3 rear plugs in the sons TJ in the coming weeks, and I am wondering what gaskets or parts, other than plugs, I will need to get before hand, if any. Do Mitsubishi supply a kit or are the parts to be used bought separately?....Any other suggestions to make this exercise less painfull or things to watch out for?

There is a steel gasket between the intake plenum and lower manifold, which can be re-used (but I got replacement new ones for about $7-00 so used the new one).

The cars are fitted with platinum plugs on rear bank from the factory, so bear that in mind with plans for replacement (ie: are they due now? if you replace them, use platinum or some other pricey long-lived stuff to avoid doing this job again anytime soon).

You may find that a rocker cover gasket and/or plug tube seals are required - these can be bought individually via Mitsi, or as kits aftermarket. (each spark plug sits in a tin tube which runs from the head up to underside of rocker cover...... there is a donut-like seal at the top, to exclude rocker cover oil from the spark plug).

If you pull the any of the plug leads off and there is evidence of oil on the insulator that goes down inside the tube, then a new plug tube seal is called for. Oil on that spark plug lead/insulator will cause the rubber to swell and eventually to weaken.... unless you live near a parts shop with these in-stock, it would be wise to have a set on-hand before you attack the rear plugs.

The cheapest place I found for the rocker-cover-gasket-and-plug-tube-seals kit was an E-bay Trader called Ultra Cheap Auto in mid-north coast of NSW - further info is in old threads in here, including approx cost and phone numbers).

Would be a good idea to cover the lower inlet manifold while you are working after you unbolt the plenum, to avoid drooping small objects down the passages.

Here is a diagram I used just yesterday to change the rear plugs and what a bitch may I add.

http://img10.imageshack.us/img10/5277/intakemanifold.jpg

Thanks fellas, the vehicle has just clicked over the 100k mark. ...When I did the front plugs before, I noticed a little oil around the plug base's, so looks like I will have to replace the seals!...... can the plug tube seal be renewed without taking off the rocker cover?
And, can the throttle body by just unbolted from plenum and left behind in position or does it have to be removed along with all the plumbing?
Pablo

can the plug tube seal be renewed without taking off the rocker cover?
Pablo

Nope. But its only a few bolts so no biggie. There is a mob on ebay called "ultracheapauto" that sells the seals ALOT cheaper than everywhere else.



And, can the throttle body by just unbolted from plenum and left behind in position or does it have to be removed along with all the plumbing?


Undo 5 bolts (4 on the side and 1 on the back) and your good to go.