I'm changing my sparkplugs for the first time (well the first time I've done it - they aren't original plugs). The Haynes is pretty straight forward but I'm wondering if yall have any secret tips to share. Thanks...

Have always used the Bosch Supers (copper). Tried the regular Bosch Platimums once and didn't seem to run as well. Judgement based on feel of course. I was under the impression that torque spec's were for clean and oiled threads. Dry would seem unpredictable (how dry is dry?). However, oil turns to carbon if heated high and long enough. Anti-sieze is aluminium or copper base. Once heard it affected heat transfer.

I don't use a torque wrench. I think more damage is done by people trying to meet torque specs, especially in aluminum, than by those who go by feel (ie. "it's tight enough"). I haven't had a loose plug, nor a seized plug yet. I've started using anti-seize.

Regarding leaking. If you look at a spark plug, you'll see that it has a collapsible washer. Probably acts as a back-up seal. So I tighten enough to compress the washer.
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1980 245 Canadian B21A with SU carb and M46 trans

I've been changing spark plugs since the 50s. Back then we changed them a lot!

I once had a '66 Dodge with a slant 6 that would foul plugs every two weeks or so. I had about 5 sets that I glass beaded at work when I ran out.

I have never used anything on plugs, although I always wipe down the threads on used plugs to clean them.

OTOH - Click and Clack do a funny discourse on those 100,000 mile plugs. "If you leave them in for 100,000 miles, they are in there FOREVER!"

They advise people to remove and reinstall plugs on a yearly bassis if they do not need to be changed. Besides, you can look at them while they are out.
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96 855R, 95 855,854, 90 744 Ti - 343,000 Volvo miles put on 7 bricks

If you haven't done it yet, you may want to read the FAQ sections on removing and installing spark plugs :

http://www.brickboard.com/FAQ/700-900/EngineMechanical.htm#RemovingSparkPlugs

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'89 244DL M47 161K miles

Use anti-seize compound on the spark plug threads and do not overtorque. Re-install with a known good torque wrench to the prescribed torque level. The threads in the aluminum head will strip if you tighten with gorilla-like strength.
chris in vermont, 244, 765 (blown head gasket) and 945.

the use of anti-sieze compound seems to be controvercial - esp. when used with torque wrench.

FAQ reads: [From AC Delco] Do not use any type of anti-seize compound on spark plug threads. Doing this will decrease the amount of friction between the threads. The result of the lowered friction is that when the spark plug is torqued to the proper specification, the spark plug is turned too far into the cylinder head. This increases the likelihood of pulling or stripping the threads in the cylinder head.


My guess is that there are people of both schools who have been doing it for years and never had any problem either way. Has anyone had a bad time with one of the methods? I'm inclined not to use any.

AArgh! It's your call on whether you wish to use anti-seize or not... and whether you wish to put a little oil in that frying pan before you fry an egg in it, or a little layer of grease and flour in that 9" x 13" pan before you put the cake batter in it...

For my part, I grew up with the notion that lug nuts on cars HAD to be jumped on and banged on and cursed and fought... because some complete (*&(*& had put them on too tightly, and Minnesota salted winters had done the rest. But I have NO desire to do that any more. Do you? Knowing that there's an alternative?

Or the almuminum engine from a Corvair I rebuilt. Horrid. I wished never to do that to anyone else, all that SEIZING.

There ARE published compensation (reduction) tables for torqueing fasteners, if you want to lube them with oil, grease, Crisco, anti-seize... and still get things right.

e.g. "* If lubrication has been applied to the bolt and/or the nut (other than the normal protective oil film), multiply the recommended torque by the appropriate factor shown in the Lubrication Factor table. n.b. Antiseize lubricants can reduce torque required by approximately 20%."

From http://mdmetric.com/tech/data1torque.html

So do a little .8 x conversion in your head, and live happily ever after!

For a Loctite brochure see http://stealth316.com/misc/antiseize.pdf

and especially the right-most column on page 3, which shows typical torque value reductions of about 15%. Easy! And satisfying, with no calories, no risk of cancer, or STDs... I can't think of a better way to have fun.
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Gregg; Mpls, MN; 1987 745, 1967 Amazon 4-dr.

I've changed my plugs twice since I bought my car and have never used anti-seize compound - no issues. Just don't overtorque...

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Jim 90 244DL with 240K!

My feeling on anti sieze compound is it is simply another product targeted at lazy joe american who wants the 100 thousand mile variety of plugs. If you give your swede some love and quick your plugs with some frequency you will not have a problem. Like others have said though just don't over torque!

While you are replacing those plugs i would suggest spending the extra money and going for a top shelf plug such as a platnum or bosch +4. I installed +4s on my 83GL and had noticably smoother idle and acceleration. This along with 8.5mm plugwires will be the first upgrade done on my "new" 84GLT. Great bang for your buck.

Love your brick
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'84 244GLT, 240k, blk,tme springs, zimmerman cross drilled rotors, upper and lower cherry turbo braces, ipd aluminum skid, euro front turn signals

Do the 8.5mm plug wires realy make a difference? I'm considering buying a set of Magnecor wires. The 7mm's are substantially cheaper than the 8.5mm's. I emailed Magnecor and a guy emailed me back saying that the wider wires shouldn't make a difference on our cars.

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Jim 90 244DL with 240K!