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Svt (mondeo st200) spark plugs

sx_turbo

New CEG'er
Joined
Jul 4, 2012
Messages
10
Location
United Kingdom
OK SO

i work in a motor parts shop here in the uk, and have a problem with the spark plugs for my svt.

the 2 manufactures that i deal with for plugs are ngk and denso.

but they both give different part numbers and heat ranges in there listings, and the oem part number doesnt cross reference into anything they list.

ngk say the spark plug heat range should be 6, and denso say t he heat range should be 16 (which is an equivalent to ngk heat range 5)

so because i have removed the egr valve and the cats etc, i wanted to go 1 heat range lower than whats listed, so i went with the ngk heat range as being the correct one.

and got a set of equivalent denso iridium power plugs IT22.

Now it wasn't until i fitted all the plugs and started it up for the first time, rev it from cold and had blue/black smoke at about 4k rpm, once it was warm it was ok, and i double checked the specs of the plugs and realised that the gap on the plugs is 0.8mm, i know stock plugs are 1.3mm gap, and the upgrade plugs are normally 1.1mm.

the car runs drives and idles a million times better than it has for the past year, but i am concerned that the spark plug gap is to small and will cause me issues if i just leave it.

i am off on holiday next week and will be cruising the mountain roads of wales (you guys might have to google wales uk) and dont want to catch myself out with a car thats gonna break down.
 
The spark plug gap should be set for the application. I have never heard of spark plugs that come pre-gapped for the vehicle they are being installed into .


Also the blue/black smoke could have happened since you rev'd a cold engine that doesn't have cats on it. I really don't think the spark plugs would cause smoke if there wasn't an issue before.
 
i am unsure as to whether the smoke occured before because i never rev or abuse cold engines as a general rule.

but because i just changed the plugs and leads i wanted to make sure it went through the rev range ok, and i had sealed the inlet manifold correctly.

in the uk, spark plugs come pre-gapped, i have taken all the ones we stock/list for the 2.5 v6 and 2.5 v6 svt and they are all pre gapped.

looking through my ngk and denso catalogues all plugs are pre gapped according to them, well in the uk at least.

back to my main question though,

would the much smaller spark plug gap cause any issue if it is running ok now?

in the uk the v6 duratec is not a loved engine and people tend to avoid it if possible, and so there is little information as to what makes these engines perform better or worse.
 
Why not have someone here state side pick you up a set of motorcraft and send them to you. Surely that would be cheaper than buying a set in the UK.
 
the reason those plugs are "pregapped" is because technically you arnt suppose to gap platinum. it gets fragile and could break. but everyone does it anyways. order a set from the U.S. Ebay.

everything i need from across the pond i order on UK bay
 
according to ford europe the 205ps engine has different plugs to the stock 2.5 v6

but, from what i can find in america, the contour svt shares the same spark plugs as the stock 2.5 v6, which is odd and a little confusing

i'm probably reading far to much into this, but would rather it right than wrong


the ford europe number is F75E-12405-CC FINIS CODE: 4763593
 
Simply order the plugs meant for a 2.5 V6 DOHC contour. U'll be fine. I'm running IT22 Denso iridums on my turbo'd car cuz it's a colder range. You shouldn't need to pay that much for those on a stock vehicle.
 
just a quick update,

so when hot the denso IT22 caused hesitation on WOT in 4th gear from 2500rpm to about 5k rpm then it cleared, i assumed this was down to the much smaller plug gap.

changed to a set of stock NGK plugs, and its fine now, so unless running boost the smaller plug gap does cause issues, shame because when the engine was slightly cold it had so much more power int it, and was a lot smoother on idle with the it22's in :(
 
just a quick update,

so when hot the denso IT22 caused hesitation on WOT in 4th gear from 2500rpm to about 5k rpm then it cleared, i assumed this was down to the much smaller plug gap.

changed to a set of stock NGK plugs, and its fine now, so unless running boost the smaller plug gap does cause issues, shame because when the engine was slightly cold it had so much more power int it, and was a lot smoother on idle with the it22's in :(

You must have one or two bad ones. Like i said before, i've been running them for 7yrs now without a problem. I would consider checking the gaps before you install them, even though you say they come pre-gappd
 
Once the engine is warm those spark plugs should cause no issue. I run denso 31's which is like 4 steps colder than stock, in -0* weather I have had them perform fine at .02 gap. NGKs are junk, densos are where its at, the hesitation is probably in the tune or something else and I'm betting is a bad spot in the tune, where the load and rpm don't hit very much. my 2 cents.

*edit* nvm thought you were boosted, didn't realize you were stock. But still, one/two steps colder should cause no issue, if not boosted, theres not reason for small gap. Increase the gap they will be fine.
 
i put the hesitation down to the plug gap of the it22 being half the size of the stock,

stock should be 1.3mm and the it22 was 0.8mm.

if i'm honest i'm gonna be selling the car, as i've got pretty fed up of it never running properly, everytime i think i've go it sussed, it starts playing up again.
 
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