# 1.8 L Spark Plugs



## Snappa (Mar 31, 2013)

What is the current spark plug part number for the OEM spark plugs in the 1.8?


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## brian v (Dec 25, 2011)

http://mychevrolet.com


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## Patman (May 7, 2011)

I believe it is 41-117 but that has been superseded by couple other plugs and is up to 41-122 
ACDELCO Part # 41122 

https://my.chevrolet.com/content/da...evrolet/cruze/2014_chevrolet_cruze_owners.pdf Page 11-14


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## NickD (Dec 10, 2011)

Same one used in the 1.4 L, don't care what you guys say, will still stick with my Autolite APP3923 double platinum. Like having some meat in that red hot combustion chamber. 

But will stick with a needle point in my sewing machine.

See rockauto.com dropped the price to $3.30, sure beats paying your dealer 8 bucks per plug.


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## Snappa (Mar 31, 2013)

What mileage are you guys changing them at? Both 1.4 and 1.8? I know it's been changed in subsequent owners manuals, so I'd like to know what everyone on here is doing.


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## obermd (Mar 3, 2012)

The 2015 owner's manual is 60K miles for both engines.


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## Snappa (Mar 31, 2013)

Is that with highway or city driving? I wonder why they have changed it so
much??


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## obermd (Mar 3, 2012)

Either the Cruze was always 100,000 Kilometers (62,137 miles) and it wasn't caught in translation or GM really did try for a 100K mile spark plug change. NGK does have a limited number of plug designs that are advertised for 100K miles.


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## NickD (Dec 10, 2011)

They use to say 100,000 miles, you also have to put a light coat of anti-seize on the threads or you will never get them out. Never was a problem with cast iron heads, but sure is with aluminum, dissimilar metals with a current flowing through ground forming electrolysis. 

Also coat the inside of the boots with dielectric grease so they don't bake on. Also good to stretch those springs so they don't hang up inside the boots, make darn sure all four are sticking out with care the boots are centered over the plugs. Working partially in the blind with these.

Since I have a walnut shell sprak plug cleaner and tester, I pull mine about every 15-20K miles or so, I like seeing that center electrode insulator white. Is a carbon path to ground for that center electrode.

Since I have been designing ignitions systems for over 30 years, I gap at 26 mils. When you hit the gas, with a turbo, get plenty of turberance that can blow out the spark. That guy that came out with the 60 mil gap at Delco was nuts, finally locked him up. 

Unit of measurement is the joule can same amount can be attained with high voltage and low spark current or just the opposite.

This is the consequence of have a weak spark. A fried catalytic converter, $$$$$$$$.


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## obermd (Mar 3, 2012)

NGK, who makes the OEM plugs for the Cruze, has flat out stated NOT to use anti-sieze on the threads of their plugs. Anti-sieze changes both the electrical and heat conductivity of the plugs.


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## jblackburn (Apr 14, 2012)

I hope to get 40k out of the iridiums. Any more will be gravy on top. 

My old car used to go 30k on coppers and they didn't have to be regapped. Idk why the Cruze is so hard on them. 

I've seen 100k on plugs in Toyotas without an issue, but run that long in a Ford and they're not coming out (they weren't fun to get out of an Escape at that mileage).


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## jblackburn (Apr 14, 2012)

obermd said:


> NGK, who makes the OEM plugs for the Cruze, has flat out stated NOT to use anti-sieze on the threads of their plugs. Anti-sieze changes both the electrical and heat conductivity of the plugs.


^^^this


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## NickD (Dec 10, 2011)

Ha, and don't blame engineers for a weak spark, had a very strict budget to meet with barely enough money to replace the ignition points. Going was back to the first HEI modules, the price to produce those was actually less than what it cost to manufacturer a set of points.

Key problem is developing a gated bipolar transistor to replace the points, make it two large, the capacitance would increase decaying the cut-off time, but wanted it large for good heat dissipation. Too small and it would burn up. Ha, I am free now, so can tell it the way it is. 

A Map sensor is far cheaper than vacuum advance as is a microcontroller for centrifugal advance until you go to your dealer to buy a replacement.


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