Changing plugs on 97 3.1L

[cocobob]

Does anyone have a trick to get the 3 plugs off by the firewall. The 97 3.1L engine does not have a hinged motor mount as does the 96. The engine cannot tilt forward and the distance is so tight I cant barely get my hans in ther.

Cheers

[rixGAphx]

I did the plugs on my '96 3.1 3 weeks ago.
Your s should be identical.
I'm a hefty guy with short pudgy fingers; this procedure would definitely be esier for a 12 year old kid, but I eventually managed it.

1. Remove the plastic fresh-air ducting from the cowl to the alternator.
2. Remove the alternator.
Not really too difficult, with the right wrenches, 14 and 19mm IIRC.
The passenger side plug canNOT be accessed with alternator in place. The other two can be (I can verify by experience) accessed without removeing the alternator, but in retrospect the center plug would have been easier to do if I had removed the alternator then.
3. Obtain 8 inch pair of right-angle needle nose pliers; nothing else in my opinion will grip the spark plug boots adequately for you to apply twist/pull force.
4. By hook, crook, wriggling, and swearing, pull off one boot at a time. Using 5/8 socket, assorted extensions and u-joints on the ratchet, remove the original plug.
5. Set the gap on the new plug. Do not EVER rely on 'factory setting' regardless of the plug manufacturer.
6. With more swearing and fineagling, insert and tighten the new plug.
7. Place a dab of silicone grease or anti-seize compound on the lip of the boot (it will smear around the plug ceramic as you install the boot); this will make boot removal so much easier next time.
Attach the plug wire, being careful not to get the grease on the plug terminal.
8. Repeat steps 4-7 for the other 2 plugs. Do NOT ever have two plug boots off at once.

9. Reinstall alternator, connect serp belt, install plastic alternator duct.

You're good to go.

I estimate I got 10-15hp from replacing the 85k-old plugs.

Good luck.
-Rick

[mikem220153]

I have done it several times on my 97, 3100. I didn't pull the alternator. Rather I pulled the Ignition control module with the coil packs attached, and the evap canister purge solenoid. With these out of the way, you have enough room to get to all three plugs and use conventional tools to do the job. Just remember to do this job when the engine is cold, use anti-sieze compound on the threads of the new plugs, and silicone grease on the plug boots. If you have a lot of miles on the engine, now would be a good time to replace the plug wires. As far as plugs, I have had good performance from the Bosch Platinum +4's and AC Delco Rapid fires. I have heard the NGK plugs work well too, but I have never tried them. I have also heard that the Bosch Platinum +4's do not perform well in the 3400 engine.

[Rayz]

Did this on both my GA's 94 & 00
Jack the car up and took off the passenger side wheel and reached through the steering opening in the wheel well and the plugs are right there.

[NaturalKonc3pt]

what is the gap supposed to be set at for a 1997 3100 Grand Am GT

[RocketFast321]

also pray your plugs are not cross threaded, that is what's stoping me from chaning them on our malibu. Dang-gum two of the front plugs where. I had to buy a .99 plug and rock it back and forth to clean it out

[mwsriders]

i have a 97 GAGT with a 3100 and i have changed/checked troubleshooted my plugs for the past week and I have used a 3in extention and a 6in extention with a sparkplug socket and 3/8 drive wrench and everything goes fine.....tool tip check out craftsman's locking sparkplug and extention set up. its cool! and oh so handy

[RocketFast321]

I ask the local repair men how they change the back plugs on a 3100. They said they remove the motor mount and tilt it forwarnd like you do on the old school 3.1 mpi

[LoneRangers15]

Originally posted by RocketFast321
I ask the local repair men how they change the back plugs on a 3100. They said they remove the motor mount and tilt it forwarnd like you do on the old school 3.1 mpi
Holla! Sorry, I got excited for a moment.:P

[RocketFast321]

ok today i seen somebody change the plugs on a 3100 by tilting it forward. It really makes a difference at getting at the back plugs.