Topic: spark plug replace
in Forum: C4 Engines
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I have a 94 C4 with a lot of miles on the clock.. I want to change the plugs or at least check them not knowing when they were changed last. After looking into the engine bay I noticed I can't even see the the plug boots on the left bank (drivers side) There is a lot of things in the way manly the "ASR" throttle cable control system. Is this just the cruise control or in it the "fly by wire" throttle control. I feel way over my head and I am just not sure were to start.. Sure coulde need some advise.
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It's not as bad a job as it looks. I bought a '94 C4 a year ago that ran rough so I did a tune up that included the plugs. The only one that was really difficult was the passenger side rear. I had trouble getting my hands in between the exhaust manifold and the A/C coil housing. But I was able to do it with help from the wife and her smaller hands.
One big tip that I can give you, especially on the driver's side, is to jack the car up, support it on a jack stand, remove the wheel and the fender liner section behind the wheel. With that out of the way with a long socket extension you can get in "under" some of the things like the ASR control module and the brake master cylinder.
Make sure you use a torque wrench to tighten the replacement plugs as you don't want to take the chance of over tightening the plugs in the aluminum heads.
The rear on the passenger side I found it useful to have a spark plug socket that has a hex at the top end so that I could put a box wrench over the hex to loosen the plug. There was not enough room for the ratchet handle, it would hit against the A/C coil housing as the plug screwed outward.
Enjoy your Vette!
One big tip that I can give you, especially on the driver's side, is to jack the car up, support it on a jack stand, remove the wheel and the fender liner section behind the wheel. With that out of the way with a long socket extension you can get in "under" some of the things like the ASR control module and the brake master cylinder.
Make sure you use a torque wrench to tighten the replacement plugs as you don't want to take the chance of over tightening the plugs in the aluminum heads.
The rear on the passenger side I found it useful to have a spark plug socket that has a hex at the top end so that I could put a box wrench over the hex to loosen the plug. There was not enough room for the ratchet handle, it would hit against the A/C coil housing as the plug screwed outward.
Enjoy your Vette!
Bob - '94 Polo Green Coupe
Basically, I agree with Bob. I remove the middle inner fender cover and there's not much to removing the ASR bolts, leave the cables and push it out of the way too. Also, the A/C support rod. The right rear (#8) is the worst for sure but it's not too bad from the bottom if you can get access to a lift and use a wrench on the socket. #6 the same way.
|UPDATED|5/28/2012 6:23:02 PM (AZT)|/UPDATED|
As it happens, I just replaced all mine. I've got 1-3/4" headers and #5 won't allow a socket on it and it's too deep into the head for a wrench. Fortunately, Snap-on has just the socket #S9723, 12 pt offset. Got get me one of those and maybe their low profile socket #S9724RHS.
|UPDATED|5/28/2012 6:23:02 PM (AZT)|/UPDATED|
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San Pedro, CA - USA
Joined: 6/20/2013
Posts: 7
Vette(s): 1992 Polo Green Coupe
1987 Bright Red Coupe
If you do the wires, get Taylor or MSD.
Plugs, I suggest NGK Platinum. The ACDelco Platinum's are garbage... there is this puck on the ground strap that burns off, turning a lovely .050 gap into a not so lovely .065 gap.
The hardest plug to reach is #8. The AC box blocks you off... I find using a conventional plug socket with a wrench head, and a 3/4" offset box wrench will get it as easy as anything.
in Forum: C4 Engines
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