99 Lumina 3.1 Spark Plugs

:banghead: Any tricks to replacing the plugs in the back of a 99 Lumina 3.1? Also looking for tricks to get stuck plug wire boots off.
I'm a pretty big guy and can't get enough leverage to pull the wires off...

There is special tool out there,it is called a GM engine moving tool.It moves the engine forward,make sure transmission is in nuetral and it is worth the money to have.Most Mac,Snap On,Matco tool dealers sell it.

It is possible to change plugs with out rocking the engine. At least on my 95, 3.1, APV. I am a big guy with long arms which certainly helps. I disconnected anywires with quick connects that might have been in the way and possibly damaged in the process. I also removed the hood, alternator and of course the air cleaner. I mirror and a strip of LED lights is most helpful as well. I also have an extra long plug socket that made the reach and line up easier. As far as getting the boots unstuck...Mine has metal heat shields around the boots that need to be twisted and rocked a little to break those loose first. Some PB Blaster shot through a tube can help. The metal shields get stuck to the inside walls from the rust and corrosion.

The vans can be done without rocking the engine forward, the cars cannot. I bought my tool at Harbor Freight, about $20. I'm sure that's way cheaper than Snap-on, Mac, etc... You can also remove the "dog bone" upper mounts and jack up the trans (use a piece of wood between the jack and the trans pan to spread the load). Be careful not to rock it too far forward, or you could damage the mounts or the engine cooling fan(s).

I just remove the upper radiator mounts and use a ratchet-strap to crank the engine foward.

I just remove the upper radiator mounts and use a ratchet-strap to crank the engine foward.

On my van I tried the upper mount removal and couldn't get the engine to budge. While working underneath on the P/S problem I found the lower mount was a yoke attached to the frame so it would appear the tilting technique would not work with this in place. Is the engine in the van tiltable at all? or does it require an extra step or two? or am I just not getting this concept?

I would even try the block oof wood trick.I call it dangerous resulting a broken hand if the block of wood slips out.The special tool is the best way to do it.

I find it easier to put her up on a ramp, and go in from underneath. An old Compact Mirror (nick one from the wife) helps too.

Now I've done the plugs so many times, I can get in from the front and feel my way around.

Gill's right. Some models mounted the steering rack on the firewall, making it easier to change them from the bottom. A lot of W body racks are mounted to the subframe, making it harder.

Sorry I did not get to this website sooner. :frown: I own a 97 Lumina w/ 3.1 engine. Its got 125,000 on original plugs but runs smooth. Mileage and performance has not got any worse. If I change these plugs what is the best replacement? I would like to only change these once since it is such a big job. Have anybody gotten performance or mileage boost from the new plugs you installed?

Sorry I did not get to this website sooner. :frown: I own a 97 Lumina w/ 3.1 engine. Its got 125,000 on original plugs but runs smooth. Mileage and performance has not got any worse. If I change these plugs what is the best replacement? I would like to only change these once since it is such a big job. Have anybody gotten performance or mileage boost from the new plugs you installed?

Regardless of what you've heard, nobody EVER got a meaningful performance or MPG boost from tricky plugs. Some are better for high-RPM racing applications, but on the street in a passenger car, you aren't going to notice any improvement, unless it's because your wallet is so much lighter:lol:

Use the AC/Delco platinum that it came with, they've done good all those miles, why change to something else?



PS, I like to live dangerously. I take the dogbones off, rock the car in park to get the motor pitching forward, then stomp the E-brake when it can't move forward any more. Block the wheels to keep it frozen like that, change the plugs.

Dogbones and wratchet straps worked great on my car. I don't know about the vans though. Before I knew about the wratcheting straps trick I was removing the belt and alternator to reach back behind.

Hey RotorBalls and jeffcoslacker - thank you for the fast response!!!
Good advice on the type of plugs - I'll use that.

RotorBalls, besides loosening/removing the dogbones how did you attach the ratchet straps and how wide were the straps you used? Did you also use that special $20 engine moving tool?

I attached one hook of the wratcheting strap to a loop on the front right side of the engine. The other end to the tow hook of my rx7 parked in the garage lol. I didn't have a hook mounted to a stud anywhere so the other car worked fine. Use a heavier wratching strap as I broke a thinner light weight one on my first try. I didn't need any tool, the straps pulled the motor far enough forward to get to it

I attached one hook of the wratcheting strap to a loop on the front right side of the engine. The other end to the tow hook of my rx7 parked in the garage lol. I didn't have a hook mounted to a stud anywhere so the other car worked fine. Use a heavier wratching strap as I broke a thinner light weight one on my first try. I didn't need any tool, the straps pulled the motor far enough forward to get to it

Yeah, whatever works LOL.

I've done something like that when a friend's car was being worked on and the E-brake didn't work well enough to do it my way...so I just took the bones out and butted my truck up behind his car and shoved it forward (in park) just enough to pitch the motor forward, then set my brake and blocked it.:grinyes:

No, that doesn't hurt the driveshafts, as some idiot tried to tell me once. The torque on the shafts required to roll a 340lb motor forward a few inches is peanuts compared to moving a 3000lb car by applying 170hp to it. Give me a break:screwy: The only thing that's getting stressed a bit more than normal is the park pawl, and I gaurantee you it's not gonna break.

:thinkerg: I gotcha now. Thanks again for the details RotorBalls and jeffcoslacker. :thumbsup: After I gitrdun, I'll let you know.

I was suprised how easy it was to move the engine when unbolted from dogbone. My mechanic showed me how to do it with a 2X4 wegding it carefully against block and firewall. Had to use short length of less than 18 inches to fit in engine compartment, but the lever sure helps. Once moved, another short lenght of 2X4 on edge (3.5 inches) is all thats need to keep engine forward. This works best with helper.