Celica Forums General Discussion Exterior Spark plug question

I bought the Bosch Platnum series plug's for my car. I pulled the Denso I radium plugs out and they were just about melted. Now for some odd reason when i am sitting at a light my car idles down to less than 100 rpm's and almost dies, Any ideas what may be causing this?

not screwed in all the way ? j/k

It might be the fact that the car needs irridium plugs, They're more conductive than platinum. Try putting new irridium plugs in. Why were the old ones melted anyway. Irridium plugs should last like 100,000 miles.

Iridium plugs have very tiny electrodes, it may look wierd to you, but that's how they are.

Iridium is super strong and highly conductive; therefore it doesn't require a massive electrode.
You need to cut it with a special laser when making it into a spark plug. That engine block would melt before the iridium does.


Odds are, it's not melted away, that's the way iridium plugs are supposed to look.

Now if it's phisically melted, then something is seriously wrong... Why not take a picture of the plugs and post it so I can actually see what you're talking about. Is the ceramic insulation cracking? Is there a lot of carbon? Different signs mean different things.

Stay away from platinums, unless you have some special things going on under the hood. Iridiums are fine.

Bosch Platinum, Platinum 2,3,or 4?. Like Rave669 said crates too much spark making your car not idle correctly. Stick with standard plug no platinum 2,3 or 4. Iridium plugs recommended NGK IFR6A11 or Denso SK16R11.

yeah, isnt there a sticker in the side of the valve cover that says to only use Iridium Plugs.

Stick with NGK or Denso Iridium

yup just like everyone said stay with the denso ones, no point on gettin the other kind, its not like you will get performance out of a spark plug, maybe 1hp but yeah, im going to get some spark plugs and now that i read this ill go for denso iridium, good luck

Bosc is a european manufacturer so they don't work to well on Japanese imports. My car had bosc plat when i bought it, after changing to Denso Iriduims the car runs smoother. Anyway why did you downgrade from iridium to platinum?

i think you need to put back iridium plugs. it says to only use iridium plugs too...like that said...the platinum may be too restrictive for the coils

Well got the denso plugs now i keep the plat's in my car for emergancies, just incase i see someone i need to throw something at.