Technical 1.4L turbo spark plugs

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Technical 1.4L turbo spark plugs

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Jan 17, 2020
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Does anyone have industry knowledge about spark plugs?

I'm really confused about what spark plugs 500x 1.4L turbo is supposed to use:

Service manual states gap 0.65mm (0.026"), but gives no part number

Ones I pulled out car were: NGK FPT 55249868 supposedly 0.7mm (0.028")
Ones I used replaced them with while back were: Bosch YR5D33S 96320 at 0.7mm (0.028")

Recently I've installed Denso IXU27 at 0.9mm (0.035")

but all of these are supposed to be compatible with Magneti Marelli 062120137312 which are gapped at 1.0mm (0.039")
 
My 500X 1.4 Turbo

ServiceFiat552498680500XSpark PlugNGK / FPT - NGK IKR9J8
ServiceNGKNGK IKR9J80500XSpark PlugNGK / FPT - NGK IKR9J8 (ECP408650030)

I stayed with NGK.

A thing with spark plugs is that:

1) Obviously same thread is required
2) Plugs have different heat rating (hot running - cold running). This is important as plugs that run too hot (depending on engine compression ratios and general head cooling) will cause detonation to occur. Plugs that run too cold do not ignite fuel as well and this causes changes to the flame front and optimum combustion and power delivery

3) Plug gap is a parameter that is generally vehicle manufacturer specified by application. Fiat may want 0.9, BMW 1.0, MERC 0.8 so the plug manufacturer will generally ship with a mid range value, e.g. 0.9 and leave the final tweak to when the plug is installed.

What 500X service manual are you referring to?
 
Thanks for the info.

according to the compatibility website, Fiat 55249868, is compatible with all the ones I listed, including your NGK IKR9J8

I'm using the MOPAR Tech Authority Fiat 500X 2015 Service Information Manual DVD.
 
Do you know what the gap is supposed to be for 500X?
Your NGKs are gapped at 0.8mm
I left the gaps as set. Just checked the plugs for damage etc. before fitting. As @chris3234 has posted these days plug gaps tend not to be that critical.

The Fiat 500X workshop manual does not specify a gap value. Just says use NGK IKR9J8 plugs.
 
Thanks guys, but as I stated at outset:

Service manual states gap 0.65mm (0.026"), but gives no part number
I asked in a previous post:

"What 500X service manual are you referring to?"

There is no such 0.65mm reference in the 500X KeyLearn Worksop Manual that I can find.

I've checked the the 500L 1.4L Turbo Engine (not MultiAir) and the plug gaps are to be set at 0.04" or 1mm.
 
Last edited:
And I answered:
MOPAR Tech Authority Fiat 500X 2015 Service Information Manual DVD.
Sorry I missed that. My apologies.

Interesting. The US / North America ..... ???? were the only regions to get the 500X eLearn DVD. I only have what the UK/EU have.

If your MOPAR Tech Authority Fiat 500X 2015 Service Information Manual DVD quotes a recommended gap then just go with that. Generally in a modern engine any gaps between 0.6mm to 1mm should be OK but if in doubt set 0.8mm.
 
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