bluefox280
New member
- Location
- Broomfield, CO
Back when I had my Stage 2 MK4 1.8T, I used to change out copper electrode plugs every 10-12K due to cheap, effective maintenance.
I was going to tackle the same on my used MK7 GTI, but due to the different "cup-shaped" terminal type on the spark plug, there wasn't an option to be found.
Wanting to have a baseline for future modifications, I went ahead and swapped out the OEM plugs and saw a lot of variance.
First, some background:
CAR: 2015 Volkswagen Golf GTI (MK7) w/ Performance Pack (purchased with 29,xxx miles)
MODIFICATIONS: none - stock power level
MILEAGE: 32,8xx miles (at time of plug swap)
Some history on the OEM plugs (P/N #06K-905-601-D), which were standard on 9+ different VAG vehicles of the current and previous generation:
* laser welded, dual platinum plug [both center electrode / ground electrode] w/ copper core
* NGK heat range = 7
* specified gap from NGK = 0.031" (0.8mm) - 0.035" (0.9mm)
* specified gap from Volkswagen = 0.032" [unconfirmed]
When I removed the OEM plugs, I measured the gap:
- Cylinder #1 = 0.034"
- Cylinder #2 = 0.032"
- Cylinder #3 = 0.035"
- Cylinder #4 = 0.035"
Visual Inspection - Cylinder #1:
- light gray ash on ground electrode = good air / fuel ratio
- slight peppering of side electrode = first indicator of overheating plug
- slight discoloration of side electrode = second indicator of overhearing plug
- HEAVY pinking of ceramic insulator = indicator of auto-ignition / knocking
Visual Inspection - Cylinder #2:
- light gray ash on ground electrode = good air / fuel ratio
- moderate pinking of ceramic insulator = indicator of auto-ignition / knocking
Visual Inspection - Cylinder #3:
- light gray ash on ground electrode = good air / fuel ratio
- moderator peppering on side electrode = first indicator of overheating plug
- slight discoloration of side electrode = second indicator of overhearing plug
- Some pinking / browning of ceramic insulator = indicator of auto-ignition / knocking
Visual Inspection - Cylinder #4:
- light gray ash on ground electrode = good air / fuel ratio
- slight peppering on side electrode = first indicator of overheating plug
- moderate discoloration of side electrode = second indicator of overhearing plug
- Some pinking / browning of ceramic insulator = indicator of auto-ignition / knocking
ONTO THE NEW - while there's been discussions on other OEM variant plugs (like the RS7 plug), or other aftermarket, in my opinion there wasn't a clear winner.
So, I elected to try the OEM equivalent replacement of the NGK PLFER7A8EG [94833].
* laser welded, dual platinum plug [both center electrode / ground electrode] w/ copper core
* NGK heat range = 7
* specified gap from NGK = 0.031" (0.8mm) - 0.035" (0.9mm)
* bluefox280's gap = 0.028"
Yes, I shorten up the gap on the stock plugs based on experience from my previous MK4 1.8T.
From looking at the original plugs, I'm concerned that if the previous owner did use premium gas 100%, but the plugs are overheating, that a 40K-60K mile service frequency is too long.
Seeing that my GTI only receives premium fuel while in the hands of my ownership, I'm anxious to see how these new plugs react in 15K-20K miles.
Thoughts? Comments? Questions? Curious to see what other DIY owners have to say.
- Erik
I was going to tackle the same on my used MK7 GTI, but due to the different "cup-shaped" terminal type on the spark plug, there wasn't an option to be found.
Wanting to have a baseline for future modifications, I went ahead and swapped out the OEM plugs and saw a lot of variance.
First, some background:
CAR: 2015 Volkswagen Golf GTI (MK7) w/ Performance Pack (purchased with 29,xxx miles)
MODIFICATIONS: none - stock power level
MILEAGE: 32,8xx miles (at time of plug swap)
Some history on the OEM plugs (P/N #06K-905-601-D), which were standard on 9+ different VAG vehicles of the current and previous generation:
* laser welded, dual platinum plug [both center electrode / ground electrode] w/ copper core
* NGK heat range = 7
* specified gap from NGK = 0.031" (0.8mm) - 0.035" (0.9mm)
* specified gap from Volkswagen = 0.032" [unconfirmed]
When I removed the OEM plugs, I measured the gap:
- Cylinder #1 = 0.034"
- Cylinder #2 = 0.032"
- Cylinder #3 = 0.035"
- Cylinder #4 = 0.035"
Visual Inspection - Cylinder #1:
- light gray ash on ground electrode = good air / fuel ratio
- slight peppering of side electrode = first indicator of overheating plug
- slight discoloration of side electrode = second indicator of overhearing plug
- HEAVY pinking of ceramic insulator = indicator of auto-ignition / knocking
Visual Inspection - Cylinder #2:
- light gray ash on ground electrode = good air / fuel ratio
- moderate pinking of ceramic insulator = indicator of auto-ignition / knocking
Visual Inspection - Cylinder #3:
- light gray ash on ground electrode = good air / fuel ratio
- moderator peppering on side electrode = first indicator of overheating plug
- slight discoloration of side electrode = second indicator of overhearing plug
- Some pinking / browning of ceramic insulator = indicator of auto-ignition / knocking
Visual Inspection - Cylinder #4:
- light gray ash on ground electrode = good air / fuel ratio
- slight peppering on side electrode = first indicator of overheating plug
- moderate discoloration of side electrode = second indicator of overhearing plug
- Some pinking / browning of ceramic insulator = indicator of auto-ignition / knocking
ONTO THE NEW - while there's been discussions on other OEM variant plugs (like the RS7 plug), or other aftermarket, in my opinion there wasn't a clear winner.
So, I elected to try the OEM equivalent replacement of the NGK PLFER7A8EG [94833].
* laser welded, dual platinum plug [both center electrode / ground electrode] w/ copper core
* NGK heat range = 7
* specified gap from NGK = 0.031" (0.8mm) - 0.035" (0.9mm)
* bluefox280's gap = 0.028"
Yes, I shorten up the gap on the stock plugs based on experience from my previous MK4 1.8T.
From looking at the original plugs, I'm concerned that if the previous owner did use premium gas 100%, but the plugs are overheating, that a 40K-60K mile service frequency is too long.
Seeing that my GTI only receives premium fuel while in the hands of my ownership, I'm anxious to see how these new plugs react in 15K-20K miles.
Thoughts? Comments? Questions? Curious to see what other DIY owners have to say.
- Erik