how to change 91 lumina 3.4 spark plugs

[ramjet60]

I just have recieved my father-in-laws 91 lumina and it needs new plugs can anyone help with this? PLEASE

[1993LUMINATOR]

buddie you can change the front 3plugs easly
Now the rear are a "BITCH" you must have car on a flat surface, remove dog bones(the 2 engine mounts engine bolts only)
and will all your might pull the engine towards you, and line the bolt holes in the lower par of the dog bone with the mount on the engine, and jam one of ur bolts thew it and it will hold the engine forward
easyest way l found then was to go on the side of the altinator and jam ur arm back there and take pluges out one at a time,
for the center one watch the O2 sencer in the exhaust,and now change plugs
But watch sence its tight its hard to make sure you have them ni all the way, the far on rear part of engine by tranny is hard to line up so must use deep scocket and get in with fingers then wratchet.

hope that helps
Brad

[1993LUMINATOR]

ok l red that u have a 3.4 sorry that is the instrucions for a 3.1

sorry l couldent help l havent had time to fiddle with my 3.4 yetLOL

[richtazz]

I believe you have to remove the upper plenum to access the rear plugs.

[Manny_boy]

there is a weatherstrip at the firewall, just above the plenium that you can remove that may give you just enough clearance for your spark plug socket.

The metal strip that the weatherstrip is on can also either be: bent upwards with a pair of water pump pliers; or you can do what a lot of 3.4 owners do, take a cutoff wheel or a die grinder and notch the sheet metal above the rear cylinders.

guaranteed to give you enough clearance.

[Schurkey]

Just changed plugs on both my 3.4 Luminas (a '92 and a '93) about a month ago. It was very easy--pull four bolts (two on each side) and LIFT OFF THE HOOD. Rock the engine forward, and the plugs come right out. This is NOT as hard as it sounds--I lifted the hoods by myself, and a helper would have made it a snap.

[Manny_boy]

ummm.... if you were able to rock your 3.4 DOHC forward, your lower engine mounts are toast. New lower engine mounts don't move... not even 1/4" no matter what gear you put it in, what you pull with, or how hard you pull.

...and truthfully, there isn't that much room between the front cam carrier and the fans.

[Schurkey]

Originally Posted by Manny_boy

ummm.... if you were able to rock your 3.4 DOHC forward, your lower engine mounts are toast. New lower engine mounts don't move... not even 1/4" no matter what gear you put it in, what you pull with, or how hard you pull.

...and truthfully, there isn't that much room between the front cam carrier and the fans.

I use a tool made by OTC for rocking the engine. It is not made for a 3.4, but can be used on one by adding a few links of chain and a bolt, then using the big black engine lifting hook as the pulling point. It bolts on where the dogbone would attach to the sheetmetal. I got it at a tool closeout "flea market" deal, and paid about $10.

The engine will rock forward perhaps 1/2 inch by adjusting the turnbuckle part of the tool by hand. No wrench needed. Yes, clearance is tight--but not that tight--at the front of the engine. Engine very much wants to return to it's original location, and I have no issues with excessive engine movement or funny noises, and so I have no suspicion of damaged/defective mounts.

Lift off the hood, roll the engine forward, plugs come right out. Oh, yeah--be sure to lube the o-rings on the plastic plug boot carrier, and the rubber parts of the plug boots. I use silicone grease.