changing spark plugs

[RF Overlord]

A mechanic once told me, or maybe I read somewhere, NOT to put anti-seize compound on spark plugs threads as this can interfere with heat transfer from the plug shell to the head...

Is this one of those things that WAS true 30 years ago, and is now different? When I changed the plugs in my MM, I didn't see any on the factory ones...and I didn't put any on the new ones...

[drobin]

Overlord, I have been using Never Seez Compound for years and did so when I installed the Reinhard package back in July 02..I haven't experienced and problems on my MM but you bring up a good question to ponder on....Does anyone know what's the scoop on this??????

Donald

[Flash]

Galling, cold weld of threads. I use it to help prevent what happened to LincMercLover's truck. http://www.mercurymarauder.net/forums/showthread.php?s=&threadid=883&highlight=boom
I don't know whether or not we only have four threads like the 5.4L's and don't want to find out the hard way.
I use Permatex anti-seize and it looks like there's aluminum particles or some other metal in it. Permatex claims it is good up to 2000 degrees F. I've felt using it also gave me consistent heat transfer on all plugs.

P.S. My comment about LML's truck in no way is meant to criticize his Ability or Methods on how LML maintains his equipment, its being "depressed" like he was when it happened is my point.

[427435]

I'm never replacing plugs again (especially the platinum ones that you can leave in for 50,000 to 100,000 miles) without using some never-seize. I had put some platinum plugs in a 4 cylinder Topaz (my commuting car) and left them there for 80,000 miles. The car was still running fine but I thought it might be time to change them again. Two of them broke off just below the hex. Turned into a very expensive plug change.

[RF Overlord]

Logan:

Do you think I should pull the plugs out now and do the anti-seize? Dennis recommended changing the copper plugs at around 30,000 miles, so should I just wait until then and put the anti-seize on the new ones?

I've got some Permatex (I think), the grey aluminum-looking stuff, or is there a better one...?

[Logan]

I'll say this. There isn't any anti-seize on the stock plugs so draw your own inferences from that.... :)

[RF Overlord]

Thanks, Logan...I wasn't positive there was none on the originals, but it didn't look like it...thanks for confirming that...

I guess if the factory plugs are designed to stay in for 100,000 miles with no anti-seize, then the coppers shouldn't be a problem at 30,000...

[Billatpro]

I've not had any experience with this first hand with or with out anti seize. We don't use it on the plugs in the funny car and heat transfer is critical here. I've never used it on any of my cars and never seen a manufactures recomendation to use it. I have heard some guys busting plugs but I think these are isolated cases.

One thing for sure I would never do is leave a set of plugs in for 50.60 or 80000 miles. I change plugs every 15 to 20000 and keep at least 3 sets in the rotation.

[ONEBADMK8]

Were going on 6 years with the 32v's now and we have never used anti-seize ever.

Ive never personally had a problem.

[WolfeBros]

Years ago...back when I turned more wrenches than I do now, there was a problem with some brand plugs when used in aluminum heads.
There actually was a galvanic action that took place due to the dis-similiar metals of the plug and the head. What happened was the plug would actually cold weld itself to the head. When you went to take plug out you would get the plug plus the threads from the head. It was rare but it did happen on occasion. I would never leave plugs in for 100k miles anway but if I did I would put a tiny amount of anti-seize on the plug and I mean tiny. It doesnt take much. There would be some heat transfer loss theoretically but I don't think it is enough to matter on most applications. The short life of a racing plug I wouldnt use it anyway. IMHO.

[cyclone03]

WolfeBros,
I have followed this thread sense it started and was going to reply because I also thought I heard about a type of plug or a praticular finish on a plug that had problems.
For some reason I think it's the old black finish on Autolights but I'm not sure.
All the new platnum tipped plugs shouldn't gall because they are made to stay in for long milage.

For what it's worth Chapion makes an anti sieze for the aviation world,actualy two products,one for Aluminum and the other for cast Iron that works well.
Be careful with the anti sieze that's sold at the chain parts stores because when they get HOT they run down the threads and contaminate the plug tip.You can tell this happens when you pull the plugs and they have a hard glaze look to them.

In short any new plug should be ok without any coating added by the installer.

[cyled]

Another thing is to change the plugs in the morning before the car is started. When the plugs are heated, they will tend to slightly expand (I am talking very very little) enough to make it possibly harder to get out (ecspecially if they have been over torqued). The colder the plug and the aluminum block the easier it will be to remove.

just another .02 worth

[427435]

Remember that when the factory advertises that the plugs don't have to be changed for 100,000 miles, the car will be long out of warranty if the plugs break off in the heads, or worse, strip the threads in an aluminum head!!! The platinum tip plugs, combined with today's high voltage ignitions, will run a very long time. The problem comes when you try to take them out. And as I found out, that can be a lot more money than a routine plug change----and the warranty is over at 36,000 miles!!

If you're changing at 20,000 or 30,000 miles, no sweat to take them out (if you can get to them easily anyway,). However, if you're going to take advantage of the current long life ignition systems, I would strongly suggest a little bit of good quality "Never-Seize".

[LincMercLover]

Update:

Well, $2900 later, we have a truck again... :(

The head shop guy said what probably happend was the plugs weren't torqued to spec, and loosened themselves up to the point that one blew. I know one thing's for sure, I'm NEVER changing plugs on that truck again! You couldn't fit a torque wrench down in there if ya had to! The MM's looks a little easier, so we'll see whenever I get a "package" for her.

[RF Overlord]

427435:

I have a Reinhart chip and the colder copper plugs...much as I'd LIKE to never have to change plugs again, Dennis recommends checking them at about 30,000 or so...for the price, it's not worth my effort to pull them out and put them back, I'll just put in new every 30,000.

LML:

Oooooo...jolly bad show...that's one of the down sides to all this marvellous modern technology...things aren't as rugged as they once were... I feel your pain... :mad:

[LincMercLover]

You're telling me! What happend to the good ol' days (and motors) that I could take a 12 gauge shot gun to, and it'd still start right up! Urgh... :mad: