damian

iTrader: (2)

any comments on my plugs and 02 coloring?

maxcooper

Looks like mine by the colors. I'll be interested to hear what people post. My impression was that I was running a good mixture or perhaps a bit lean sometimes (white/tan stuff) and rich other times (black).

You have a lot of wear on the second plug from the left. I wonder why that one is so much more worn than the plug to its right, which I assume is the other leading plug.

-Max

adam c

iTrader: (2)

Put them back in. They will last another 100k...........HAHAHA

I think the coloring looks ok. How many miles on them?

damian

iTrader: (2)

hey max, i am not as adept at 'reading' the colors , but i do know that my car ran well, this was a stock setup with a dp and catback, dunno about that one that is a bit more worn, I'll have to compare to the next set I pull out.

adam, 30K miles on the plugs and sensor

Rx7aholic

iTrader: (22)

This info is take directly from mazda Rx7 specialist book, They said this a frequently asked question? Reason is that the leadings plugs are fully exposed to combustion and the Trailing plugs only fire throug a 1/8" hole into the combustion chamber. Also they prolonged idling,storage,traffic or high speed driving may shorten plugg life by 50%. I am very curious what part is your plug?

poss

iTrader: (5)

so how do you get 100% out of these plugs?

i changed out my plugs yesterday and they looked similar. consistently brown and black.

damian

iTrader: (2)

>>Also they prolonged idling,storage,traffic or high speed driving may shorten plugg life by 50%.

jesus, what is left LOL!!

>> I am very curious what part is your plug?
what do you meant ?

Tim Benton

iTrader: (1)

I'm wondering why the O2 is white? Is that coated white or burned to hell and back white metal? I friends was like that, but I can't remember is it was a white coating you can wipe off or not. Just speculation, but if it wipes off, is it some ash residue from a certain type and grade of oil (ie castrol 10w30), coolant, or if its white metal from extreme heat, running lean or rich since both raise the exhaust temp if going to far in both directions. From what I could gather from Rick Engman, dealing mainly with NA engines, the plug should be about halfway milky brown to a darker brown in regards to what he thinks is safe and what corresponds with the color on the plugs.

Tim

damian

iTrader: (2)

>>I'm wondering why the O2 is white? Is that coated white or burned to hell and back white metal?

It is not burned white, it is a residue that you can rub off if you rub hard enough....I cleaned this one once before and re-installed it, just used a mild hardness metal brush and brushed the white stuff off.

>>From what I could gather from Rick Engman, dealing mainly with NA engines, the plug should be about halfway milky brown to a darker brown in regards to what he thinks is safe and what corresponds with the color on the plugs.

well if that is the case then my plugs look pretty good :-)

maxcooper

The leading plugs also fire twice as often due to sharing the leading coil in a wasted spark ignition system.

My question was mainly why is ONE leading plug so much more worn than the other one. Leading plugs wear faster than trailing, but why is there such a difference between the two leading plugs?

Damian, I don't mean to alarm you, as this is probably no big deal. It is just kind of interesting, so I am curious what the cause is.

-Max

damian

iTrader: (2)

good question max....weird anomoly :-)

deggial

I had the same type of wear on my plugs. When I took them out the plug wires on the plugs that were not as tight had less wear. The difference were huge. One leading looked like it had a year of use and the other maybe 3 months.

edit: the rear leading plug had more wear.

RotorMotor

iTrader: (5)

At what point would one replace the O2 sensor? its not part of the 30K tuneup is it?

rynberg

Those look almost exactly like the plugs I just changed a few months ago. Mine had 12k on them with a downpipe and cat-back.

Mine were the oem plugs BTW (the new ones are as well).

artowar

iTrader: (1)

Mine have always looked like that too. Ditto for 02 sensor.

jramosrx7

Change the plugs every 15K miles, max!!!!

apneablue

The last set I changed I posted the same pick...mine looked exactly like yours and most everyone said I was runnin lean...

I've put new plugs in and have been dyno tuned since then so it would be nice to check and see how they are doing again.

Marshall

Mine look like that too and I'm running 11.5 AF max on the wideband (mostly 10.5-11.5)

damian

iTrader: (2)

wowo, this was my old post but suddenly got a bunch of replies, thanks guys :-)

apneablue

Wait till you see threads dug up from 2001...now that's old!...

My favourite is when the nooobs go into the classifieds section and dig up some thread of someone selling a DP or something from back in 2001 and then here in 2003 they go "I'll give you $130 and I pay the shipping!"

damian

iTrader: (2)

LOL that is funny apn :-)