Here are the pictures and steps I followed to replace my spark plugs and spark plug wires on my 98 Seville
I ordered my parts from
www.rockauto.com
ACDELCO Part # 41950 More Info {PLATINUM PLUG #88892834} SPARK PLUG $5.08 each
ACDELCO Part # 748N {#12192081} WIRE KIT,SPLG INCLS ALL 8 SPLG WIRES $100.89 set
GAP needs to be set on the plugs!
I have 117,000 miles on the car now, when I bought it, it had 73,000 and I am assuming these are the original plugs and wires.
1. Remove the beauty cover, I think they were 1/2" sockets. The 4 in each corner.
2. I thought I was going to have to label each plug, but the #'s are stamped on the block. Thanks GM! No thanks to Chrysler
2, 4, 6, 8 are on the front. 1, 3, 5, 7 are in the rear.
3. Each plug on the coils are also labeled.
4. In my case the wires for plugs 2 & 4 were bundled together and 6 & 8 were the same way. Then those 4 all went into a piece of wire bundle. My original (I'm assuming) spark plug wires also had the # stamped on them. My new ones from Rock Auto did not, what a bummer.
5. In my case I chose to remove the metal plate that the 4 coil packs are attached to. Unplug the 4 electrical harnesses that are plugged into the coil packs. Two plugs on each side.
6. The plate has four 10mm bolts that hold it in place. One on each of the short sides and then two on the back side of the plate facing the firewall. The two side ones are easy to get to. The two on the back side are a bit harder. The hardest one is below the Cruise Control module area under the wires attached to the coil pack for plugs 3 & 8. First Picture below is removing that bolt:
The second rear bolt has a what looks like a positive electrical connector on it as well:
7. Now that the coil packs can be moved out of the way you will see the other four rear plugs.
8. Now Remove all of your spark plugs carefully keeping the spark plug wire near. I chose to set the boot back in the hole the spark plug came out of so I would not lose the routing of the original spark plug wire.
9. Once all your plugs are removed, install your new plugs with
the plug gap set to .050" My plugs were not gapped, but the instructions indicated that anyway. The FSM says to torque the spark plugs to 11ft-lbs.
10. Now that your new plugs are in carefully remove one spark plug wire at a time, remembering how it was routed. Route your new cable the same way the old one was. Secure it on the spark plug and then onto the corresponding Coil plug. As you do each spark plug wire, reapply the wire wrapping and secure it to protect the spark plug wires from heat. Make sure the plug wires are in the little 'divots' for the wires so they don't move around.
11. Double check all your boots and plugs on the coils before re-bolting the coil plate to the block.
12. Start the car, check for any problems, if no problems detected, re-attach the beauty cover!
Here are my old plugs:
