changing plugs on C5
Thread Starter
Intermediate
Joined: Jul 2004
Posts: 26
Likes: 0
From: Heath Ohio
changing plugs on C5
I feel stupid asking this but what is the easiest way to replace plugs on a 99 C5. Seems on the drivers side there is no room to get at the back 2 plugs. I grew up working on cars in the 70's etc, where you had all kinds of room. Anyway the car runs fine but coming up on 75K so thought i would change plugs//wires. thanks
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 235
From: Bangkok, Thailand
I used a long socket that I bought (I think) at Autozone. It's about 6" long and works perfect. If you have a 3/8" ratchet with a swivel head you're set.
Make sure that the engine is dead cold to help avoid stripping the spark plug threads in the head. Use anti-seize on the new plugs for sure! Other than that, it's just a normal plug change.
Click the link in my signature to go to the site to buy the plugs and wires
Make sure that the engine is dead cold to help avoid stripping the spark plug threads in the head. Use anti-seize on the new plugs for sure! Other than that, it's just a normal plug change.
Click the link in my signature to go to the site to buy the plugs and wires
Melting Slicks
Joined: Jul 2006
Posts: 2,332
Likes: 31
From: Silver Spring MD
Used regular plug wrench except for #7: $4.99 swivel at AZ
For all but the last one on the drivers side, #7, used straight plug wrench and various length extensions. For #7 first moved some hoses out of the way then used an el cheapo swivel plug socket from AutoZone. Don't need a $50 Snap-On socket when you need to use it on 1 plug. Loosened plugs with socket but removed and replaced them with a short piece of vacuum hose over the plug. This way when inserting you will not cross thread them if you can screw them in a few turns by hand. If not then you are cross threading the plug. GM says no antisieze as it changes torque values. My right hand is my torque wrench. I used antisieze to insure they come out for the 150,000 mile change. Thought my wires would be destroyed taking them out so I got the red vette wires. My black ones came out fine and tested good with my ohmmeter. Now I have more goodies in the auto parts bin.
BIGHANK
BIGHANK
Race Director
Joined: Jan 2007
Posts: 16,513
Likes: 4
From: Official Dirty Dozen Member
Racer
Joined: Aug 2001
Posts: 310
Likes: 0
From: Tomball Texas
Remove AIR tube on the drivers side no need to remove it on the passenger side. I use a 3" extension and a plug socket for all cylinders. You should only need the ratchet to break them loose or final tighten. The socket or socket+extension is what you should use to thread them in, they should thread in with ease all the way. I change, or at least check the heat on my plugs after every track outing, so mine may be easier than others.
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
The 70's were the golden years of working on cars, ease of reaching things and belt brackets were not insanely designed. The 80's became the years of agony and bizzarre contortions needing entire GM service manuals just for bracket and belt locations. I've left a lot of skin and blood under the hoods of many cars working at the dealership and a few grease smudged manuals all thumbed up almost unreadable.
TODAY when I pull my plugs it's a treat and very easy, you'll wonder what all the fuss was about.
TODAY when I pull my plugs it's a treat and very easy, you'll wonder what all the fuss was about.
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Pro
Joined: Apr 2008
Posts: 628
Likes: 4
From: Columbia SC
If I could get the G-D boots off the plugs I could do the plug change all right. Boots won't twist to break stiction, metal shields blocking access to all but the top of the boots, don't want to mar or destroy shields as I understand they are not available. What a nightmare.
Burning Brakes
Joined: Jun 2010
Posts: 1,014
Likes: 5
From: Rockwall TX
IF you have the original plug wires you might want to get new ones as well. You will probably break one or two removing then. When you do remove them, I found that twisting them until they pop worked well for me.
Melting Slicks
Joined: Jun 2010
Posts: 2,809
Likes: 3
From: Yorktown Virginia
Well the easiest way is to remove them is to do it while your manifolds are off and headers make it pretty easy to get the plugs back in. But if you remove or get the AIR tubing out of the way it frees up a lot of room for the #7. I didnt care about saving my old wires as they had 100,000+ miles on them so I just grabbed the wire itself after I disconnected it from the coil pack and pulled as hard as I did. I think that method worked for 4 or 5 of the plug wires. Another thing that will give you some more room is to remove the alternator and the coil pack mounting brackets, its like 6 bolts and really simple to remove.
Melting Slicks
Joined: Jun 2010
Posts: 2,809
Likes: 3
From: Yorktown Virginia
Oh and another thing dont forget to use di electric grease on the plug wire connections so they will be easy to remove the next time and FWIW I just used a little bit of oil on the threads of the plugs when I put them back in. I figured I didnt have any trouble getting them out this time after 100k, 20 or 30 they will be fine.
