Does anyone know the plug gap for 1992 Pontiac Lemans 4 door? The shop person told me it was 60. The plugs I bought now is 45 and I somehow suspect that 60 might be too wide.
Also what is the torque number for tightening the plug?
Where can I get a repair manual
Books4cars.com has a used factory manual:
http://www.books4cars.com/result3.asp?finddesc=lemans&imageField2.x=26&imageField2.y=11
Do you have an owner’s manual? It might list plug gap.
Look underneath the hood for a specifications sticker. (usually on the upper radiator support)
This will provide the plug gap spec and this sticker always takes preference over any manual or what anyone says. Always.
If the plugs must be regapped do this very carefully. Do not apply any pressure to the center electrode.
As to plug torque I would advise learning to do this without a torque wrench. Torque numbers, especially on aluminum head applications, are often a bit high for my tastes and can lead to thread pulling; which can then lead to stripping.
Run them down to just snug and give them another nudge. (palming the ratchet head so very little leverage is applied to the handle will usually do it) Hope that helps.
.060 might be “correct” but .045 will work fine…Check e-Bay for a service manual…
Back in '92, they used .060 plug gaps to try and prevent misfire at idle with a very lean mixture. But a .060 gap puts quite a bit of stress on the ignition system, which gets worse as time goes by. The voltage needed to jump the gap and fire the plug gets so high, the spark starts looking for another place to go and you get ignition breakdown. Do your plugs have gaskets or not?
.045 is the gap, 15 foot pounds is the torque.
do not have the manual. Am going to ask auto parts stores. Called them and some say 60 and some say 45 and some say 60 is for platinum.
My brand is plantimum plus.
One store told me I should buy AC Delco. Does the brand matter>
Risking the possibility that I’ll sound like an echo; raise the hood and check the underhood sticker as I mentioned.
The sticker is the final authority and what it shows could be different that what any manual or person may state.
I would also be very antsy about applying 15 Ft. Lbs of torque to a 14 MM plug shank. More like 6 or 7.
Plug torque depends on whether they are tapered seat or gasketed…
The sticker under the hood is no help if the car manufacturer changes specifications after the car has been in service a couple of years. I have had it happen to me twice and both times the new gap is narrower when they find out that the ign. system can’t handle that wide a gap. I had one car that they downsized the oil filter size because they found out oil wasn’t getting to the cam soon enough.
I agree, but I wouldn’t even put 15 pounds on a gasketed plug much less a tapered seat one.
There is an advantage to using a narrower gap on spark plugs; assuming the engine is running fine with no apparent problems.
A plug with a wider gap is rougher on ignition components (wires/coil/etc) and is more prone to misfires than plugs with narrower gaps.
Personally, I don’t care at all for a gap that is .060 wide.