johngammel

At the Pier show in St. Pete had discussions on C4 maintenance and trouble shooting. So for my 1988 Corvette with a stock L98 350 (the standard engine) should I use anti-seize on the Delco FR5LS plugs (these are what the car came with per my parts book)?

Cruisinfanatic

doesn't hurt. They will go in easier

PatternDayTrader

No, but if you already did, then don't worry about it. Leave it.

John A. Marker

Yes, use anti-seize. Any dissimilar metals that are fastened by means of threads should utilize anti-seize. Over a period of time there is galvanic corrosion from the different metals and this becomes like a glue. Aluminum heads, intake, runners to plenum.....always use anti-seize on the steel bolts. Same for the spark plug. If you do a search or some in depth reading here you will find many threads where the steel bolts have broken off in aluminum because of the galvanic corrosion. Save yourself a headache and a trip to the machine shop and use anti seize.

383vett

I use antiseize on any fastener that goes into aluminum (unless there is a helicoil).

haxxx

I know most manufacturers now, including AC Delco, NGK, and Denso explicitly say not to use anti seize on the spark plugs. Most of it is for over torquing reasons. Kind of moot point anyway on these cars, because good luck getting a torque wrench near there. I'm not sure about their cheap spark plugs but all the iridium plugs are coated from the factory to prevent them seizing anyway. I've never had a problem pulling iridium plugs with no anti-seize that have been in the car for 100k+ miles.

The plugs you are using may require anti-seize so I would put a little on anyway and be mindful about how tight you put them in. They really don't need to be very tight, especially with anti-seize.

Whaleman

I always learned to use the copper anti sieze on plugs as it conducts electricity. Dan

DGXR

I also use a tiny bit anti-seize on plugs or sensors that require grounding (including the knock sensors), even if it is not called for. Just be extremely careful not to get any on the electrodes. A tiny bit will go a long way if applied correctly.
The general rule is to reduce the torque value by 15% when using anti-seize as it lubricates the threads, hence the over-torquing comment earlier in this thread. Most plugs and sensors should be tightened carefully if you can't actually get a torque wrench on them. I may have put a *little too much torque on my LT1 spark plugs because I used anti-seize and could not get a torque wrench on them, but I didn't go crazy. It's running great.

Whaleman

I agree. Every picture of anti-sieze on plugs I see is about 10-20 times more than needed. It is way less that most think. You could really coat the threads and wipe them with a towel and what is left is enough. Dan

PatternDayTrader

According to the instructors at the Chevrolet tech center, you are not supposed to use anti seize on spark plugs.

JrRifleCoach

Champion and AC make a blended Anti-Seize for aircraft spark plugs to conduct heat from the plug.
I was instructed that common AS will insulate causing the plugs to run hotter.
IMHO use sparingly. Don't coat the threads, rather paint a line down the threads about 1/8 inch wide.
This will distribute as the plug is installed.

YMMV

aklim

Have you ever seen it happen that a fastener comes off because of anti-seize?

vader86

Yes, use a dab of anti-seize.

Tom400CFI

This thread is good entertainment.

Paul Workman

It only took ONE plug that came out with some of the threads from the head clinging to it to make me a fan of the stuff. And, I too put only a smear/swipe down the threads - not even enough to fill the threads - applied with a tiny dab of anti-seize on a finger tip. That's all it takes to insure the plugs will not become married to the heads (I find). (I've heard of plugs backing out as result of using the stuff, but have never experienced it myself.)

John A. Marker

I have never had a plug back out. Just wondering HOW that happens when you have the spark plug boot tightly on the plug?? My guess is that someone started the plug by hand and forgot to tighten it.

As noted above, Go sparingly with the application of anti-seize on the plug threads. Doesn't take much.

mickey5

Way back when a plug wrench was 13/16 and you gave it a half turn after the compression seal snugged up, plugs used to squeak when you took them out. I put a dab of grease when putting new ones in during the annual tune up, but was told not to, as the coating interfered with the heat transfer and subsequent heat range of the plug. What did us shade tree greasers know anyhow???

aklim

In theory, I suppose it could interfere with heat transfer especially if it was plain old grease that cooked from combustion heat. How much difference it could make might be a good question Enough to change the heat range? I doubt it will.

MatthewMiller

FWIW the 96 FSM does not call for any thread compound of any kind when installing plugs.

FresnoVette

I've used anti seize on lugs nuts as well. Use the proper torque and recheck after 50-100 miles youre good to go.
As for plugs, again use a torque wrench in two steps and double check when finished.