what is the best way to change plugs on my 94 lt1

 

You just gotta do it. The passenger side rear is the most difficult to get to, you may have to remove the...I can't think of the name, but I think it is the exhaust gas recirculation tube. The rest are pretty easy to get to given the right tools. Best of luck!

 

I did mine this spring and it was a full weekend bitch for me. I just did a quick search but didn't come up with the threads I found back then.

Passenger side: 2 and 4 are OK, 6 a little harder. 8 is the killer. I got my hand stuck in between the AIR pipe and the body when I did the work because my wrist and hand swelled up while in that place. I got # 8 on and torqued down, then couldn't get the spark plug wrench off. I had to take it back out and LOOSELY put the spark plug wrench on the plug. Be careful to not get it cross threaded when you start # 8 and leave the plug wrench loosely on the plug. I used a crow's foot wrench on my torque wrench to torque it down. When you get frustrated just sit down and take a deep breath. If you still have the stock cast iron manifold it is going to be a bitch no matter what tools you use. If you have the time to go to Sears before starting, buy a 3/8" breaker bar to use to turn the plug wrench. It's about the only thing that lets me reach into tight spots on the Vette. You will find a socket wrench head is too large to fit in some spots.

On the driver side, pull and lay back the ASR control. Unbolt and take away the center wheel well panel. I remember pulling the alternator back but I'm not sure if that was for the plug or the wires. Twist the plug wires to loosen them as you pull them off. Use anti-sieze on the plug threads and di-electric grease on the plug electrode if the plugs aren't pregreased.

Have lots of sockets, universals, and extensions handy. Don't overtighten the plug, the spec is about 11.5 ft/lb, which is about the minimum reading of my 3/8' torque wrench.

Keep your cell phone on your body ready to dial 911 in case you get your hand stuck on # 8.

If it takes all of two days don't feel bad about it. This is like MT. Everest to LT1 owners. Chaning the wires is a whole nother deal, just the K2 of Vette work.


[Modified by 94lt1torchred, 1:36 PM 9/13/2003]

 

Have somebody else do it :lol:

Take off the fender skirts, just the centers and rears.- it will make the job a lot easier. You may want to remove the bracket that holds braided fuel lines in place, it will give you a little more wiggle room on the passeneger side.

You may want to consider changing the plug wires...but that may entail more 'fun'.

Good luck

 

if you're gonna do it, get the right plugs... don't use the AC Delco brand platinum plugs... they are junk.

I recommend NGK... either platinum or iridium.

 

As an added comment, I'm in the middle of puttiing on TPIS headers. To do it I had to pull the plugs. I put them back in BEFORE reconnecting the AIR pipe. What a difference!!! I could use my torque wrench on all four passenger side plugs without extensions, well, a universal for number 6.

I'm going to have to cut the AIR pipe and rig up some kind of quick disconnect. Having that pipe out of there makes all the difference in the world on number 8. That thing only blows air for 4 minutes on startup, what a pain it is for what little it does.


[Modified by 94lt1torchred, 9:38 AM 9/14/2003]

 

First off this is only my experience but I have tried the following plugs:

1. AC 41-906 OEM's (new set of stock factory plugs)
2. NGK TR55 V-power
3. NGK TR55ix Iridium
4. AC Rapidfire #14 (Rapidfire's are numbered by heat range etc.)

The AC Rapidfire's are installed now and it runs better on them than it did on the others, idles better, pulls better. There is a forum product review of the Rapidfire's by Hib Halverson here: https://www.corvetteforum.com/review...=461&TopicID=2

#14 is the correct Rapidfire for the LT1, according to the product catalog on http://www.acdelco.com

Now for the change job. The first time you do it, i.e. when you're a C4 plug change virgin... it sucks. It's just a learning experience. #'s 1, 2, 3, 4, and 5 are pretty straight-forward, but in order of difficulty #8, #7, and #6 can be slow and tedious. #8 is the worst, and the beotch can be getting the old one loose. You need a looooong ratchet handle because its hard to get leverage (be sure to counter the leverage w/ other hand on the socket!) in that confined space with a standard length handle. I have been lucky in that the jack handle extension that came with my old '94 Dodge Dakota truck fits snuggly over the length of my ratchet handle and made a perfect extension for the first time I had to change the original plugs-- they were in really tight as factory installed, felt a lot tighter than the spec 12 lb-ft of torque for the aluminum, but probably was the fact they had been in for 7 years since '95.

Anyhow, do not be afraid to change your own. It will probably take you 4 hours, but just plan for it and have take breaks. The good news is after the first time you do it becomes quicker. Takes me 90 minutes now.

Expect to nick and scratch your wrists, knuckles, and forearms. When fighting the #8 plug there is a plastic fastener for the air cond. lines (?) that has a nice little barb on the inboard side right where your forearm has to squeeze through :cuss , at least on my '95 anyway.

Be sure to use anti-seize compound! Some say use copper based, some say the silver/grey type (Permatex brand) is better. There was something mentioned once about a copper based anti-seize being not the best choice because the copper reacts slowly over time with the aluminum head threads and the metal plug threads and does something undesirable. Can't recall the specifics.

Many will say you need several universals for your ratchet/socket and such but I'm here to tell you that I've found the best to be a regular old ratchet w/ regular old spark plug socket (keeping in mind the need for long handle for #8 plug). I have tried using a universal joint adapter between the ratchet and the socket but found it to an experience similar to trying to f#@k w/ with a limp d#@k.

 

The best method I've found is at least one beer per plug. The job sucks but by the end of it you'll be laughing instead of crying and you will not feel the pain. Good luck, the second best method is to cut a check. :cheers:

 

Like everything else on these cars - ain't nothin' easy!!

That said, plugs can be changed in two steps......

Step one - remove the engine from the vehicle.

Step two - change the plugs!!

:lol: :lol: :lol: