Welded-On Spark Plug Boots

Hello all,

'99 Chev Malibu, 3.1 v6, 145,000km

Changing spark plugs for the 1st time (on this car). Front 3 went smoothly. Rear plug boots seem to be welded onto the plugs (higher heat at the back??).

Anyway, I'm changing the wires too. Any tips on getting the old boots off (short of using explosives??) Don't care if I mangle the old wires in the process.

Regards, Al.

Just take a knife and split them....

Or break the plug porcelains. You can just pull the wires up and off and then unscrew the plug stubs from the heads.

I replaced mine at 50k, put the old plugs and wires back in the plastic bag the new ones came in and stuck them under the hood. If I ever would develop some sort of problem I can stick the old not quite worn out ones back on one at a time to isolate a bad one. Did the same with the fan belt, if the new one breaks I stick the old one back on and take the new one to the store for warranty replacement.

Right you are. Got them off and now nothing but joy (grin). Anyway, put a good dose of silicone grease in the boots at both ends of the cables. Hope the job goes easier next time.

BTW, GM seems a bit optimistic with their 100,000 mile double platinum plugs. Mine looked pretty rough at 90,000 miles.

Regards, Al.

. Get a tube of dielectric grease to put inside the new ones before

The last set of wires I bought, the autolight pro series, already had dielectric grease inside the new boots.

I would be a bit leery of pulling spark plug wires too much. Sometimes when you pull the wires the metal clip inside the boot won't detach from the plug, and instead pulls out from the boot itself, destroying the connection to the wire.

Ted

I don't really have much useful to say here except a bit of head shaking. It seems a bit strange to me now in 2004, after ALL these years of spark plugs, that we are still pretty much using a fairly antquated design for connecting the power distribution lines to the plugs. So much has improved in materials and processes over the many many decades. You would think that by now the design would have been improved a bit more and resulted in a much better mechanical binding of the wire to plugs etc.

Anyway... just wishful thinking for now.

Well, no...not necessarily. Take a look here:

Those 6 things on top of the valve cover are individual coil packs that just plug onto the spark plug.

Here you can see the plug in it's little cubby hole. This is becoming very common. A number of engines use this (or very close to it) system.

Ian

That's pretty cool. There is hope! My LS1 engine has 8 coil packs, but each one still has a (albeit short) wire to the plug. Still the boots and all that like has been for so long. Speaking of which... at how many miles would YOU change plugs on an LS1 Ian? I've read some people say that the GM interval is too long to wait. Maybe GM knows best, maybe not.

Also, do you have any tips on the easiest least time consuming method to replacing that really hard to reach plug on it? I have a 2001 Z28 if that helps you get a better image.

It's really up to you. We've seen some engines that have over 150,000 klms on them with original plugs. If it was my vehicle, I'd probably just do it every so many years no matter what the mileage. If you have cast iron heads, it really doesn't matter. With aluminum heads, I've seen a lot of vehicles that the spark plugs end up being welded into the head because they were in there so long. Then the "long life"...."more economical" spark plugs all of a sudden aren't so "economical".

Not really. I haven't actually changed plugs on that car yet. We don't see many of those cars in the shop as it is. Other then the proper tools and (hopefully) small arms and hands...that's about all I can offer ya.

Ian

That sounds really scary (read expensive to fix). I sure wouldn't want that to happen. I wonder how long it takes for that.

Unfortunately I have large arms and hands, and no lift. I just hate ethe idea of not being able to change my own plugs though. Would be the 1st time ever for that.

Hi...

Dunno if I'm wasting a few cents every time I change a plug (in anything) or not; but I always put a little tab of anti-seize grease on the threads...

Ken

Engine ICE cold. Let sit overnight. Have small forearms. You'll do #8 from below. It'll take an hour-ish. With platinum plugs you can probably do it every 3 years - with nitrous I've gone to regular plugs so it's a yearly thing. (2001 TA)

Ray

Thanks Ray. I have rather thick lower (and upper for that matter) arms. Also, this is 2004 and it's a 2001 so I suppose I should be thinking of plugs. I don't think I'm due yet according to the "book" but... anyway.

This might seem dumb but, why cold engine? Does heat expand the metal of the plug at a faster rate than the metal of the engine, and of course the converse?

Ice cold is because you're going to be touching the exhaust manifolds a lot. Burns suck. :)

Use a dab of antisieze on the new plugs. It took my buddy and I about an hour and a half to change the plugs. A couple are easy - a couple are a real PITA. We used a pickle fork (the ball joint tool) to pop the plug wires off a couple because there's no room to twist the wires and get any leverage in there...

you could see the impressions from the manifolds on my forearms after...

Ray

Yes, especially with aluminum heads. Not as critical with iron heads. Pulling plugs in a hot aluminum head is a good way to ruin the threads in the head. Anti-seize, as mentioned by others, is ok. Just be careful not to get it on the insulator or on the electrodes. It is conductive and will cause misfire. Best used very sparingly. H

Sheesh. Changing plugs used to be easy.

Ahh. I know my block is aluminum, and it seems the head is too but I thought I read somewhere the LS1s have a iron head on aluminum block. Does anyone know?