My Denso plugs after 25k - Mazda 6 Forums : Mazda 6 / Mazda Atenza Forum

late8 · 10-08-2009, 10:11 PM

Knock readings were climbing up according to my AP during the last week of daily driving (amp. temps in mid 70s.) Yesterday, after crusing on the freeway between 75-80 mph for an hour, I exited and coasted to the stop sign and pulled a typical "California stop" and slowly rolled through and gave the throttle a tap and my knock reading shot to 5.8; knock reading is usually partial throttle between .3 to .7

Fearing the "I exited the freeway and popped my motor" syndrome, I drove home and pulled the plugs. The Densos have been in the motor for at least 25k.

After doing some research, I'm still confused on how to read these plugs. I've added some pics my Denso and highlighted some possible problem areas with arrows on the #3 plug.

My concerns on the #3 plug is that the jetting hasn't completely covered the ring as the other plugs show and the strap is discolored and slightly burned more than the other plugs.

Am I reading my plugs correctly? There are tons of photos on spark plug webites on bad or problem engines but I'm confused on what direction the discoloration is supposed be headed on the strap. Is the plugs too cold by the color?

As a side note, I didn't have a second set of new Denso plugs so I re-installed the NGK iridiums that I used for just a short time. Just to see how the car would react on my current fuel trims, I didn't bother resetting the ECU after swapping back to the NGK's.

My knock readings are back down to .3 to .7 and the throttle response is so much quicker and the butt dyno says the car pulls harder.

I'm thinking that I needed a set of fresh plugs?

Thanks in advance for the help!

Turbo6Girl · 10-08-2009, 10:22 PM

They look like they are burning evenly and don't look bad IMO. This is how mine looked on my NGKs with 25K~ miles when I switched to the Densos. I think you probably just needed new plugs but it doesn't look like there is a major issue with how they have burned.

Click here for a burn chart.

late8 · 10-08-2009, 11:32 PM

Thanks Turbo6Girl for the chart link.

late8 · 10-08-2009, 11:51 PM

After viewing the burn chart, would spark plugs pulled from a DI motor have the same normal burn or wear pattern as the plugs found on a standard chart?

Quakeguy · 10-08-2009, 11:53 PM

They seem to be too hot.

EDIT: I should state that the previous statement is a general combustion temp statement and may not be related to plug temp rating.

late8 · 10-08-2009, 11:57 PM

Maybe go 2 step colder?

late8 · 10-09-2009, 04:12 PM

QUOTE (Corpus_Speed6 @ Oct 8 2009, 08:53 PM)

Quote:

They seem to be too hot.

EDIT: I should state that the previous statement is a general combustion temp statement and may not be related to plug temp rating.[/b]

Hey thanks for the heads up! I double checked the AP map I loaded a while back and sure enough I flashed the 93 octane instead of the 91 version. Shit.

p057 · 10-10-2009, 08:20 AM

QUOTE (late8 @ Oct 9 2009, 04:12 PM)

Quote:

Hey thanks for the heads up! I double checked the AP map I loaded a while back and sure enough I flashed the 93 octane instead of the 91 version. Shit.[/b]

Lol.

Switching back to the denso's then, are you?

MS6Mike · 10-12-2009, 12:23 PM

Yeah that white color means youre running hot

late8 · 10-12-2009, 12:40 PM

QUOTE (P057 @ Oct 10 2009, 05:20 AM)

Quote:

Lol.

Switching back to the denso's then, are you?[/b]

Yup,....ordered from SU. $47.50 shipped!

10-08-2009, 10:22 PM	#2 (permalink)
Turbo6Girl Rally Racer Join Date: Oct 2006 Location: Where the anal itching parasites are, also known as Draper, Utah. Or is it Ohio? I can never remember. Posts: 1,833 Thanks: 1 Thanked 8 Times in 5 Posts Groans: 0 Groaned at 0 Times in 0 Posts iTrader: 0 reviews	They look like they are burning evenly and don't look bad IMO. This is how mine looked on my NGKs with 25K~ miles when I switched to the Densos. I think you probably just needed new plugs but it doesn't look like there is a major issue with how they have burned. Click here for a burn chart. __________________ The official non-6 owner forum lurker, harasser and racket queen. 1993 Probe GT, Hawk HPS pads, Continental ExtremeContact DW's. More goodies waiting to be installed. 2006 Black Mica MS6 Sport, 65K miles and one hell of a love/hate relationship. She will be missed. Centric Brakes from R1 Concepts CLICK HERE

10-08-2009, 11:32 PM	#3 (permalink)
late8 Rally Racer Join Date: Nov 2006 Location: Sacramento CA Posts: 1,318 Thanks: 0 Thanked 0 Times in 0 Posts Groans: 0 Groaned at 0 Times in 0 Posts iTrader: 0 reviews	Thanks Turbo6Girl for the chart link. __________________ '06 Black Cherry Mica MS6 GT w/sunroof Engine/drivetrain: Cobb AP (Stg.1 91 v1.02) AEM SRI w/ air straightner, Speedie6's T.I.P, Forge BPV, Denso ITV22 spark plugs, SU Silicon Boost Tubes, silicon recirc. and vac. tubes Saikou Michi OCC w/ 2 PCVs, CP-E Motor Mount, SU Stiff Diff bracket Exterior: Badgeless AE style grill, 18x7.5 Kazera KZ-T Silver Rims, 215/45/18 Hankook V12 Evo Bilstein shocks, AutoEXE Lowdown springs, SPC ball joints, Magnaflow catback, Redline Tuning hood shocks, Interior: Lotek gauge pod w/ ProSport boost, water, volts gauges, TWM stage 2 short shifter w/bushings, Redline short shift boot

10-08-2009, 11:51 PM	#4 (permalink)
late8 Rally Racer Join Date: Nov 2006 Location: Sacramento CA Posts: 1,318 Thanks: 0 Thanked 0 Times in 0 Posts Groans: 0 Groaned at 0 Times in 0 Posts iTrader: 0 reviews	After viewing the burn chart, would spark plugs pulled from a DI motor have the same normal burn or wear pattern as the plugs found on a standard chart? __________________ '06 Black Cherry Mica MS6 GT w/sunroof Engine/drivetrain: Cobb AP (Stg.1 91 v1.02) AEM SRI w/ air straightner, Speedie6's T.I.P, Forge BPV, Denso ITV22 spark plugs, SU Silicon Boost Tubes, silicon recirc. and vac. tubes Saikou Michi OCC w/ 2 PCVs, CP-E Motor Mount, SU Stiff Diff bracket Exterior: Badgeless AE style grill, 18x7.5 Kazera KZ-T Silver Rims, 215/45/18 Hankook V12 Evo Bilstein shocks, AutoEXE Lowdown springs, SPC ball joints, Magnaflow catback, Redline Tuning hood shocks, Interior: Lotek gauge pod w/ ProSport boost, water, volts gauges, TWM stage 2 short shifter w/bushings, Redline short shift boot

10-08-2009, 11:53 PM	#5 (permalink)
Quakeguy Track Racer Join Date: May 2007 Location: Corpus Christi, Tx Posts: 881 Thanks: 2 Thanked 0 Times in 0 Posts Groans: 0 Groaned at 0 Times in 0 Posts iTrader: 0 reviews	They seem to be too hot. EDIT: I should state that the previous statement is a general combustion temp statement and may not be related to plug temp rating. __________________ Formerly known as Corpus_Speed6 - 06Speed6 on MSF... The handle change is gay.

10-08-2009, 11:57 PM	#6 (permalink)
late8 Rally Racer Join Date: Nov 2006 Location: Sacramento CA Posts: 1,318 Thanks: 0 Thanked 0 Times in 0 Posts Groans: 0 Groaned at 0 Times in 0 Posts iTrader: 0 reviews	Maybe go 2 step colder? __________________ '06 Black Cherry Mica MS6 GT w/sunroof Engine/drivetrain: Cobb AP (Stg.1 91 v1.02) AEM SRI w/ air straightner, Speedie6's T.I.P, Forge BPV, Denso ITV22 spark plugs, SU Silicon Boost Tubes, silicon recirc. and vac. tubes Saikou Michi OCC w/ 2 PCVs, CP-E Motor Mount, SU Stiff Diff bracket Exterior: Badgeless AE style grill, 18x7.5 Kazera KZ-T Silver Rims, 215/45/18 Hankook V12 Evo Bilstein shocks, AutoEXE Lowdown springs, SPC ball joints, Magnaflow catback, Redline Tuning hood shocks, Interior: Lotek gauge pod w/ ProSport boost, water, volts gauges, TWM stage 2 short shifter w/bushings, Redline short shift boot

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10-12-2009, 12:23 PM	#9 (permalink)
MS6Mike Track Racer Join Date: Sep 2006 Location: Southington, CT Posts: 230 Thanks: 0 Thanked 0 Times in 0 Posts Groans: 0 Groaned at 0 Times in 0 Posts iTrader: 0 reviews	Yeah that white color means youre running hot __________________ 2006 Velocity Red Mica MS6 GT <blockquote> Cobb AP*Stage II CPE Intake / Speedie6 TIP / CPE Motor Mount / CPE 3" Downpipe +cat / PG CDFP Upgrade RPM Smoked Rear LEDs / RPM Smoked LED Side Markers / MSD Dashhawk / CX7 Antenna MB Boost wheels + oem Rubber (hot) / oem Wheels + Pirelli Sottozeros (cold) </blockquote>