Recent Topics
amazon missing package. how often?
by WhyMe
51 minutes 15 seconds ago
Filter Minder naysayers!
by ThunderOne
Yesterday at 09:57 PM
Is there a 1 piece 75 Ohm to 300 Ohm coa connector
by daves66nova
Yesterday at 08:46 PM
Help me choose camper wheels
by spasm3
Yesterday at 08:44 PM
2012 Ford 3.0 V6 Kendall GT1 5W-20 7295 mi.
by AITG
Yesterday at 08:19 PM
FCP Euro Oil change...which oil for N62 BMW
by TXCarGeek
Yesterday at 07:48 PM
Suggestions on HM Oil to treat consumption
by shurguywutt
Yesterday at 07:44 PM
Another headlight "restoration" using 3M kit
by 92saturnsl2
Yesterday at 07:42 PM
Switching to QS Ultimate 5w30
by oilchangeguy
Yesterday at 07:18 PM
6L80 pan with drain plug
by 04SE
Yesterday at 07:00 PM
Fly or drive 2700 miles for company training
by Mr Nice
Yesterday at 06:42 PM
Censored for [censored]
by Pajero
Yesterday at 06:25 PM
Lexus SC430 Factory Repair Manual Set
by law3500
Yesterday at 06:10 PM
How to get the online price at Walmart?
by Oldtom
Yesterday at 05:27 PM
Cylinder head thickness?
by Hemispheres
Yesterday at 05:06 PM
Finish Kare question
by 007
Yesterday at 04:51 PM
ArmorAll wax wipes
by avacado11
Yesterday at 03:45 PM
Meguiars products on special for Prime Day has
by SirTanon
Yesterday at 03:15 PM
Most Expensive 18 Front wheel drive ,cheapest RWD?
by andyd
Yesterday at 03:00 PM
My advance auto gold battery life (story)
by edwardh1
Yesterday at 02:21 PM
Newest Members
Denniso, roadwarur, Auzoo2, Greaser73, Mitsu_Joe
65497 Registered Users
Who's Online
29 registered (Bailes1992, Astro14, AVB, AlaskaMike, 10WSmuckers, aleneros), 894 Guests and 33 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
65497 Members
67 Forums
287203 Topics
4791154 Posts

Max Online: 3590 @ 01/24/17 08:07 PM
Donate to BITOG
Page 1 of 2 1 2 >
Topic Options
#4600774 - 12/11/17 02:34 PM Gap the spark plugs or leave them?
mclasser Offline


Registered: 04/13/13
Posts: 2257
Loc: The Northeast
I've got OEM NGK plugs on the way for my Infiniti. FSM calls for a 0.043 in gap, but they come pre-gapped @.044 in. A lot of people say not to mess with the gap and just drop 'em in.

Since gaps open up over time I think I should set them to spec from the get-go. What do you guys think?


Edited by mclasser (12/11/17 02:35 PM)
_________________________
2018 Hyundai Elantra VE -- 3K
2013 Honda Pilot EX-L 4WD -- 55K
2002 Honda Accord EX-L -- 210K


Top
#4600778 - 12/11/17 02:37 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
bdcardinal Offline


Registered: 06/03/05
Posts: 11072
Loc: Santa Barbara, CA
Put them in as is. Would not lose sleep over .001" difference. You aren't building a race engine where you modify the electrode shape and index the plugs.
_________________________
2014 Ford Mustang GT Track Pack
1995 Ford Mustang GT

Ford/Mazda Parts Counter
NRA Benefactor Member
Opinions expressed are my own.

Top
#4600787 - 12/11/17 02:49 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
fenixguy Offline


Registered: 02/08/17
Posts: 308
Loc: NC
I wouldn't mess with them myself. I always check new plugs but that's plenty close enough.
_________________________
'16 Frontier SV 4x4-PP/Nissan OEM
'08 CR-V EX AWD-Valvoline Syn MaxLife/Fram TG
'01 Civic EX-Valvoline Syn MaxLife/Fram UG
'00 Civic LX-PYB/Fram UG

Top
#4600790 - 12/11/17 02:52 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
The_Nuke Offline


Registered: 07/21/13
Posts: 313
Loc: D/FW Metroplex
Verify they are within the range of acceptable gap for your application (into which 0.044" does indeed fall) before you stab 'em.

I've had plugs come pre-gapped at a different gap than what was listed in the book, so checking for that first and adjusting if found is more important than trying to close the gap 0.001" IMHO (something which would be very difficult to accomplish with any degree of accuracy I would think).
_________________________
2012 Dodge Charger
- R/T with pursuit pkg.
- 5.7L + A5 + 2.65
"..it's got cop tires, cop shocks, cop suspension..."

Top
#4600791 - 12/11/17 02:53 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
OneEyeJack Offline


Registered: 09/14/10
Posts: 7485
Loc: S California
There's the thought that they are correct and your measurement is off .001. smile

Top
#4600799 - 12/11/17 02:59 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
mightymousetech Offline


Registered: 04/03/17
Posts: 1470
Loc: Ontario, Canada
If they have a platinum ground electrode, they can not be regapped.

And 0.043 vs 0.044? Just leave them.


Edited by mightymousetech (12/11/17 03:00 PM)
_________________________
Mighty Mouse Tech
Acura Tech
2010 Civic Si Castrol 0W40, Redline MTL
2013 BMW 135i M Sport Edition Castrol 0W40, Redline MTL

Top
#4600800 - 12/11/17 03:00 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
Silk Online   content


Registered: 07/26/03
Posts: 4609
Loc: New Zealand
It's a Japanese vehicle, the gap is 1.1mm, which is 0.0433070088'' Get it right - .043 is too tight, .044 too wide, set it to 1.1mm.
_________________________
1987 BMW R65 - Penrite V Twin 20/50
2005 Nissan Expert - Gulf Western 10W-40
1996 Volvo T5 - Penrite HPR15 - 15W-60. Ryco syntec filter.

Top
#4600810 - 12/11/17 03:09 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
SHOZ Offline


Registered: 06/28/03
Posts: 5802
Loc: Illinois
I always gap mine a couple thou under. But I would not put them in without checking them.
_________________________
2008 Hyundai Accent 1.6L 5 sp manual hatchback
2010 Hyundai Genesis Coupe Track 2L Turbo 6sp manual

Top
#4600855 - 12/11/17 04:30 PM Re: Gap the spark plugs or leave them? [Re: Silk]
slacktide_bitog Offline


Registered: 03/20/08
Posts: 6350
Loc: USA
For the I35, I would strongly suggest iridium, sine they are impossible to replace in your car since you have to remove the intake to access them. You may also want to replace the valve cover gasket, the rear 3 fuel injectors, clean the EGR tube, and possibly replace the knock sensor, too.

Platinum is good for 60k. Iridium is good for 100k

Denso #3417 or #4703

Originally Posted By: Silk
It's a Japanese vehicle, the gap is 1.1mm, which is 0.0433070088'' Get it right - .043 is too tight, .044 too wide, set it to 1.1mm.


+1

Top
#4600903 - 12/11/17 05:30 PM Re: Gap the spark plugs or leave them? [Re: slacktide_bitog]
dkcase Offline


Registered: 10/20/02
Posts: 735
Loc: Suburban St. Louis
If indeed the original spec is 1.1mm (accurate only to the tenths place), you might think that could be rounded from 1.051 to 1.149. In which case correct could be 0.041 to 0.045. I'd say leave them.

Top
#4600950 - 12/11/17 06:31 PM Re: Gap the spark plugs or leave them? [Re: dkcase]
Kira Offline


Registered: 08/19/10
Posts: 5409
Loc: Champlain/Hudson Valley
I vote for post #4600800. Very funny.

Top
#4600960 - 12/11/17 06:51 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
Merkava_4 Offline


Registered: 01/30/07
Posts: 17501
Loc: Clovis, CA
I would gap them! If you leave them at .044" when the manufacturer specifies .043" - you're losing .001" allowable electrode wear. That's a huge amount of wear for spark plugs that you would be just giving away.

Top
#4600986 - 12/11/17 07:16 PM Re: Gap the spark plugs or leave them? [Re: Kira]
Rick in PA Offline


Registered: 01/04/03
Posts: 3203
Loc: Southeastern, PA
Originally Posted By: Kira
I vote for post #4600800. Very funny.


Slow night here. It turns out the last significant digit is less that the diameter of an atom.
_________________________
A wise man told me:
"Heat is your friend." and "Any oil is better than no oil."

Top
#4601029 - 12/11/17 08:13 PM Re: Gap the spark plugs or leave them? [Re: mclasser]
Linctex Offline


Registered: 12/31/16
Posts: 6186
Loc: Waco, TX
A big gap is my friend - - always has been.

Olds Big Blocks in the 70's were gapped at .080" !!!!

I usually open everything up to at least .050-.055", sometimes .060" before installing them.
_________________________
"The evidence demands a verdict".
(Re:VOA)"it's nearly impossible to actually know the particular additives that are in there at what concentrations."

Top
#4601035 - 12/11/17 08:17 PM Re: Gap the spark plugs or leave them? [Re: Merkava_4]
Linctex Offline


Registered: 12/31/16
Posts: 6186
Loc: Waco, TX
Originally Posted By: Merkava_4
I would gap them! If you leave them at .044" when the manufacturer specifies .043" - you're losing .001" allowable electrode wear. That's a huge amount of wear for spark plugs that you would be just giving away.


No, it isn't.

Sparks jump from sharp edges - the distance (gap) is NOT as important as having a sharp point/edges.
That is why iridium plugs have such a tiny wire in the center.

I have seen it on the dyno - old, worn plugs with rounded electrodes gapped down to .040" will always make less power than new electrodes with sharp edges gapped to .060".
_________________________
"The evidence demands a verdict".
(Re:VOA)"it's nearly impossible to actually know the particular additives that are in there at what concentrations."

Top
Page 1 of 2 1 2 >