Oh I am so mad my dealership had the wrong gap on my plugs

[joeharth]

I got 20k miles in my car. I dont ever want to take it to my dealer ship. I did an air filter change and now just changed the plugs. I guess I should have changed the cables too. The old plugs had a gap of 0.04, that should explain my low 30mpg. Any tips on what I should change next.

[BLAZINBLUEVITZ]

not for nothing but those plugs are iridium and do not need to be changed for at least 100k. oh, and the come pre-gapped......
PS: there's coils no wires........

[YarisSedan]

Yeah going back to techical training school when i was a new mechanic i was taught never to gap iridium spark plugs since you may damage the electrode tip. They come pregapped. I would only gap plugs like copper core ones. I mean it may be possible someone dropped the plugs on the floor before they installed them which closed the gap a bit.

[ka0sx]

bull crap, i regaped my iridium plugs on 1jz for hotter spark, performance.



edit: though replacing the plugs at 20k is fucking ridiculous.

[supmet]

Q. Do I need to set the gap?
A. Generally, no. The DENSO Iridium Power plug comes pre-set with a protective sleeve over the firing end, to protect the gap from accidental alteration. DENSO Iridium Power’s ultra-efficient firing power compensates for normally recommended gap settings that are smaller than the pre-set value. In the cases of vehicle modifications (nitrous, turbo-chargers, super-chargers, high power ignition systems, etc.), some adjustments may be desired. Or, if you prefer to remain consistent with factory specifications, you may adjust. However, please be careful not to place any stress on the fine center electrode during adjustment. You could accidentally break off the very hard, and therefore brittle, tip.

http://www.densoiridium.com/faq.php

=====================

Should I gap my Iridium Plugs?

The manufacturers say NO.
This is because most people do not know how to properly gap a spark plug, and the center electrodes on the ultra-fine iridium can easily snap if mishandled. There is no warranty for snapped center electrodes. The manufacturers say an iridium spark plug will run so much better than a traditional plug, even if it is not gapped for that motor, that they would prefer you just leave it rather than risk snapping the center electrode.
Personally, we at sparkplugs.com, gap our iridium plugs for our own vehicles (we’re rebels). If you insist on gapping your iridium plug, please refer to Proper Gapping for instruction.

http://www.ngk.com/faqmain.asp

[joeharth]

May be my bad but everywhre I read I see GAP=0.032 and it was 0.4. Ill let you know if my mpg increase. I put some bosch platinum plus plugs

[nemelek]

Depending on your cummute, driving habits, stop and go traffic, weather, winter fuel blends, the low 30's might be a normal mpg figure.

[Tamago]

May be my bad but everywhre I read I see GAP=0.032 and it was 0.4. Ill let you know if my mpg increase. I put some bosch platinum plus plugs

great, a downgrade..

from denso iridiums

to bosch platinums


:facepalm:

[Loren]

Why guess at what the spark plug gap should be when the Yaris factory service manual is available online???



Check the spark plug electrode gap.
Maximum electrode gap for used spark plug:
1.3 mm (0.051 in.)
If the gap is greater than the maximum, replace the
spark plug.
Electrode gap for new spark plug:
1.0 to 1.1 mm (0.039 to 0.043 in.)

So, the .04 that you found was well within factory specs. Gap increases as plugs age, so there was no problem there.

FWIW, one of my factory plugs gave up before 20k miles. I was getting random misfires at high rpm on the track. Cured it with a set of good ol' NGK plugs. I suspect that I could probably put the factory plugs back in for street use.

[1stToyota]

May be my bad but everywhre I read I see GAP=0.032 and it was 0.4. Ill let you know if my mpg increase. I put some bosch platinum plus plugs

The owner's manual for my '08 states Iridium spark plugs only. And unless you've got forced induction you might want to increase your gap to around .040/1.02mm ...don't think you're in any danger of spark blowout on a stock Yaris. :rolleyes:

[MUSKOKA800]

I installed new NGK Iridium plugs annually in the snowmobile since 2003 and always checked / corrected the gap to meet Arctic Cat's spec.
Usually the plugs are spot on out of the box but occasionally one needs to be tweaked to match the other. Didn't put automobile type miles on them but never had a plug issue in this nasty, oily, 2-stroke environment.