BigOLundh

iTrader: (1)

Quick Summary... i'm boosted on the 8, and the last time i went to the dealership they swapped my plugs for 6 Leading and 9 Trailing. That is two hot for a turbo application so i bought a new set of 9 Leading and 9 Trailing plugs, and swapped them out 2 weeks later. Also, within those 2 weeks the car was detonating when under boost. We richened up the fueling, to stay safe until I got a chance to replace them.

This is where it gets interesting. After only 2 weeks, the OEM plugs looked horrible. I'm not sure if these are just "dirty" or actually "dead". Either way, I didn't think a plug should look like this after 2 weeks.

I'm wondering if the problem might be:
1 - Their heat range was too hot, and hence went bad
2 - Problem with the Spark Plug Wires
3 - Problem with the Coils
4 - Something Else

For issues 2 and 3, does anyone know how to test this? Thanks!!

Below are the pics. The first 2 are the Leading Plugs, and the second 2 are the Trailing Plugs. Its hard to tell in the pigs, but the Leading Plugs look slightly worse than the Trailing Plugs

-hS

dannobre

iTrader: (3)

What's wrong with them?? They look OK to me.

cleoent

look good 2 me as well...

BigOLundh

iTrader: (1)

So do you think they just need to be cleaned?

cleoent

I dont think they need anything. They aren't white, they aren't fouled.. they're just spark plugs. Perhaps one of the more knowledgeable types can jump in here though, but from my eyes they look fine.

MazdaManiac

iTrader: (3)

Those are normal looking plugs.
Additionally, 6/9 is NOT too hot for turbo apps unless you specifically can trace any pre-igition problem to the plugs, which is unlikely.
7/9 is probably better in general, but you don't know that for sure I bet.

Spin9k

They live in a combustion chamber after all, so they do dirty, hot work. But they look perfectly good to me, excellent in fact.

BigOLundh

iTrader: (1)

Alright... this is good to know. I can rest easy knowing everything behind the plugs is probably still working fine.

MM - There was consistent detonation issues when under boost with the 6/9 plugs. With the 9/9 i am now running slightly leaner and have no detonation issues. FYI - i'm now using the NGK Platinum Plugs that Mazsport sells with the extra shims on the trailings.

I'll probably clean off these plugs and sell them on the board to someone who is still Nomrally Aspirated. For NA application these should be fine.

-hS

OfficerFarva

Glad to see u got sum nicer plugs. I milked the oem ones I had for all tehy got. When they were dirty I cleaned em up w/ brake parts cleaner and put em back to work. I too am interested in a colder set up now, like the 9-9 plugs u speak of. But, I'm not gonna mess w/ it until I get the new starter, cus w/ those colder plugs and the old starter I would start worse.

snkpkp

i have seen bad plugs and these are FINE.

BigOLundh

iTrader: (1)

Once you get the starter in, call up Scott at Mazsport and get his 9/9 plugs... they are working great, and are just fine with the new starter.

BTW, his 9/9 Platinum NGK plugs are cheaper than the 9/9 Uridium NGK plugs that come from factory (and can be purchased directly from the NGK website).
His also have an extra shim to make the trailings fit properly.

-hS

Go48

Yes they are. The nice tan color on the center insulator is exactly what you want to see. Don't worry about the light black carbon material you see on the metal parts.