Light grey or tan deposits and slight electrode erosion
Carbon Fouling
Dry, soft black carbon on the insulator and electrodes Symptoms:
Poor starting
Misfiring
Faulty acceleration
Causes:
Faulty choke - over rich air/fuel mixture
Delayed ignition timing
Bad ignition leads
Plug heat range too cold
Pre-Ignition
A melted or burned center and/or ground electrode, blistered insulator and aluminum or other metallic deposits on the insulator Symptoms:
Loss of power causing engine damage
Pre-ignition occurs when combustion begins before the timed spark occurs
Causes:
Plug insufficiently tightened
Engine insufficiently cooled
Ignition timing too advanced
Plug heat range too hot
Over Heating
An extremely white insulator with small black deposits and premature electrode erosion Symptoms:
Loss of power at high-speed or during heavy load
Causes:
Plug insufficiently tightened
Engine insufficiently cooled
Ignition timing too advanced
Plug heat range too hot
Mechanical Damage
Bent electrode and a broken insulator, dents often present on electrode Symptoms:
Misfiring
Causes:
Plug nose is too long for engine head
Foreign object (bolt/nut) in combustion chamber
Oil Fouling
Wet, oily black deposits on the insulator and electrodes Symptoms:
Poor starting
Misfiring
Causes:
Wrong piston rings, cylinders, and valve guides
Fuel mixture oil content too high
Broken Insulator
Insulator is cracked or split Symptoms:
Misfiring
Causes:
Severe detonation
Incorrect tool/torque applied during installation or removal
Careless gap setting
Torched Seat
Melted in the thread and seat area of the plug housing Symptoms:
Loss of power causing engine damage
Causes:
Plug insufficiently tightened
WHICH SPARK PLUG IS RIGHT FOR ME?
Auto makers built their cars to be maintenence-free, and no prudent consumer in their right mind would buy a car with plugs that you have to change every 3000-5000 miles these days (unless it was a hand-me-down used car). Most modern day vehicles will use iridium, while most are using platinums.
Platinum plugs (and Iridiums) were introduced to provide longevity (60k-100k+) to vehicles compared to copper plugs which foul after 3000-5000 miles, but they do NOT dissapate heat fast enough (which leads to pre-ignition/detonation) and do NOT provide a "better spark" like they have claimed...with their "fine-wire electrode" (which only causes problems).
Copper is one of the best conductors of electricity and heat, but they just plain dont last. Using Platinum and Iridium plugs, the center electrode (fine-wire) thin, that under high boost, they get so hot, they will begin to "heat glow" and cause premature ignition in the combustion cycle (pre-ignition => detonation) unless they were properly designed to pull the heat. This is a problem for all of us turbo guys running high boost. Copper on the other hand, has a much thicker center electrode, on top of that, the copper material is able to dissapate heat from the combustion chamber fast enough to keep the combustion temperatures lower. Coppers use thicker electrodes simply based on the fact that they can easily jump the spark, whereas platinum and iridiums will require a fine wire to better direct the spark to prevent missfires.
Remember the two primary functions of a spark plug:
1) To efficiently ignite the A/F mixture without mis-fires (Gap, etc)
2) To pull heat from the combustion chamber into the head, where the cooling system should dissapate that heat. (Heat Range)
With those two in mind, coppers will work much better in these environments. For those thinking: "What If I just simple use a colder Platinum plug?" Well, for the kind of boost our A4's make with the Krispy-Kreme K03's, we will reach EGT's of over 900 degrees C (keeping in mind that pre-ignition can start to occur at around 870 degrees C). Once those colder platinums reach preignition temperature, it will take them FOREVER to dissapate that amount of heat (with the details about the material/design I mentioned above). A platinum/Iridium plug in a colder heat range usually runs just as hot as a copper in the standard heat range when under high stress. So many people will use a Platinum/Iridum plug TWO steps colder to counter that. But using a plug that is 2 steps colder, will lead to two things:
1) More prone to carbon-fouling on "normal driving" where EGT's are kept low. (Plugs must stay above 550C Deg to burn off excess carbon deposits to "self-clean")
2) As a result, loss of horsepower from a less efficient/inhibited spark.
You need a plug that is actually "hot enough" to ignite the A/F mixture as hot as possible to get the most efficient combustion, as well as burn off carbon-deposits (~550C deg), and yet cold enough to prevent pre-ignition when compression is high (< 870C Deg).
HOT - NGK #6 (OEM Range)- Stock car with stock boost/timing, or mildly-tuned car in cold climates.
Recommended plugs in this heat range:
NGK BKR6E (Copper)
NGK BKR6EIX (Iridium Version of the same plug above)
Denso K20R (Copper)
Denso IK20 (Iridium Version of the same plug above)
NGK PFR6Q (OEM Platinum) - If you're planning to stick with stock boost
COLD - NGK #7 (One Step Colder) - Cars with basic performance upgrade (chip/intake/exhaust) - k03, k04, etc.
Recommended plugs in this heat range:
NGK BKR7E (Copper)
NGK BKR7EIX (Iridium Version of the same plug above)
Denso K22R (Copper)
Denso IK22 (Iridium Version of the same plug above)
COLDER - NGK #8 (Two Steps Colder) - Cars with bigger turbos will benefit from these, whereas a regularly chipped car may foul these.
Recommended plugs in this heat range:
Champion C63YC (Copper)
NGK R5672A-8 (Copper, Non-Resistor plug)
NGK BKR8EIX (Iridium)
Denso IK24 (Iridium)
Bosch FR5DTC (Copper)
Bosch F5DPOR (Platinum/Side Fire)**
** - Many members have found real good luck with the Bosch F5DPOR's, this is why:
Despite all the "con's" about platinums (poor conductivity, poor heat dissapation qualities), the engineers at Bosch has managed to engineer the F5DPOR's so that they are still able to fire the A/F as well as pull away enough heat. The F5DPOR's unlike conventional plugs, use a "Side-Fire" technology, where instead of a standard "projected" electrode into the combustion chamber, the ground electrode was placed on the edge of the plug so that it fires closer to the flame kernel. By doing so, the F5DPOR's are able to still keep a thick center electrode (to pull heat away faster) without having to go with a smaller electrode in order to fire. The F5DPOR's heat range is also equavalent to that of a NGK #8 (TWO steps colder than stock), in order to give the same effect as a #7. But because it is a platinum plug and not copper, they will not foul "as" easily where a copper would have. Because of these two important attributes, Bosch was able to use these plugs to both last like other platinums (up to 60k), while still function under more extreme environments. Platinums however, still do not compare to iridiums in longevity, as well as heat/electro conductivity.
Quick cross-reference guide for all the plugs listed above in heat range:
(VW/Audi Factory heat range in bold)
How cheap are the copper plugs? Can you actually feel a difference in performance?
Answer:
Originally Posted by kristokes
I got mine for $3 each so $12 for a set of 4.. For that price, it's worth trying them out yourself
Question:
Originally Posted by jimrobbington
Also, do you recommend a .028 gap on the coppers?
Answer:
Originally Posted by kristokes
I gapped the plugs from it's specs (0.028") to 0.032" (do not go over). The minute I fired up the car, the exhaust tone became a LOT deeper. So I took the car around the block, then on the highway doing some 0-100MPH pulls - the car became a LOT smoother! The powerband of the turbo will now make boost past 5000RPM and the spool-up became noticeably quicker. The hesitation I used to experience at 5000RPM disappeared and the idle became a lot smoother.
By simply switching spark plugs, I would say that my "butt-dyno" pretty much felt another 5-10hp difference in power.
Question:
Originally Posted by matthewb2795
Stock gap is .028 right? .032 is recommended for tuned cars. Or is the opposite true?
Answer:
Originally Posted by kristokes
Well it depends on what you mean by stock but coming straight from the factory, our OEM spark plugs are actually UNDER-GAPPED at 0.027". Since OEM spark plugs were made for longevity (~50k+ miles), they were set at a lower gap because the gap will eventually get bigger through time and wear on the electrodes.
IMHO from personal experience, I believe a 0.032" gap is optimal for our cars.
Since I currently use NGK spark plugs on my B7A4 and quite familiar with them, let's go over what to look for and what to set the gaps at when using NGK as an example (the same concept can be applied to other brand spark plugs)
This is how NGK's numbering system typically works:
Most NGK spark plugs you find at your local auto parts store end with a (-xx) after the part number; which signifies a pre-gap.
For example, if you got a set of BKR7E-11's (although those are very hard to find), the -11 denotes a 1.1mm or 0.044" pre-gap. A BKR7E-8 would be a 0.8mm or 0.032" pre-gap, and so forth.. However, part numbers that do NOT have a (-xx) such as BKR7E will indicate the default gap of 0.0315" (basically a 0.032"). So do NOT get that confused.
Many people who use the BKR6E's often buy the BKR6E-11's instead since it's OEM recommended for many vehicles, which comes with a HUGE gap of 1.1mm or 0.044". In order for it to work properly with the gap you want (0.032"), you need to bang the crap out of the ground strap just to make 0.032". But by then, the strap is already crooked and bent. This will lead to more mis-fires and pre-mature wear. You typically want a spark plug that's pre-gapped as close as possible to your desired gap - best way to keep the center and ground electrodes parallel.
A general rule of thumb:
Always stay within a +/- 0.008" gap range when re-gapping. Basically, a 0.032" plug should be gapped no less than 0.024" and no more than 0.040". (This applies to most plugs using a single ground electrode strap. Multi-electrode straps are a different beast that I'm sadly not familiar with.)
Last edited by kristokes; 08-01-2011 at 03:20 AM.
Reason: Added Q&A
Stokes|Moderator - PM me with any questions/concerns
Just a note on choosing between a copper and irridium plug. The coppers are 3-4 times cheaper, but the irridiums will last 5-6 times longer...so even though coppers are cheaper to buy, the irridiums are the better value overall. I have ran both the plugs below and did not notice a difference in performance, smoothness, idling, ect. Got about 5k out of the coppers, 30k out of the irridiums.
NGK BKR7E (Copper)
NGK BKR7EIX (Iridium Version of the same plug above)
2005 B6 A4 Ultrasport 1.8TQ6M USP CLUB MEMBER #46
GIAC FX | Stasis Streetsports | 345mm Brakes | 034 DV | Carbonio | Podi | Forge | APR
I ran the NGK BKR6Es in my VR6 on low boost and fouled them allll the time which wasnt surprising. I have the BKR8Es now and they have been awesome. Probably need to change them every couple of months but it takes all of five minutes so no big deal.
|| Britalman Quad tip || Custom Britalman downpipe || H&RCoilovers|| 19" HRE 540R || Hardwired Valetine One || Two tone Alcantara seats|| Podi Boost gauge||
That's what I went with on the BKR6E plugs I swapped in. The plugs I pulled out were OEM, probably in there since it was built 92K kms ago! Gap was well over 0.035 and they had hard white deposits on them.
I gapped the plugs from it's specs (0.028") to 0.032" (do not go over). The minute I fired up the car, the exhaust tone became a LOT deeper. So I took the car around the block, then on the highway doing some 0-100MPH pulls - the car became a LOT smoother! The powerband of the turbo will now make boost past 5000RPM and the spool-up became noticeably quicker. The hesitation I used to experience at 5000RPM disappeared and the idle became a lot smoother.
By simply switching spark plugs, I would say that my "butt-dyno" pretty much felt another 5-10hp difference in power.
Stokes|Moderator - PM me with any questions/concerns
Selling Nogoro blue Alcantara door panels. Will fit b6/b7 a4/s4/rs4. In great condition, originally wanted $600 shipped but dropped price to $500 shipped. Check my classifieds for pictures. I want these gone, will include extra door clips if requested. PM me if you want pictures of them installed or anything else I want these gone so make me an offer and we'll talk.
Awesome write up, should throw these into the Tech section or else they eventually die off and only to be found via search function :(
05.5 B7 - Quartz Grey
APR Stage II - K&N Drop In - Piston DV "D"
DTM Front w/ Fogs :: Non S-Line RS4 Grille :: 18" BBS RC :: H&R Sport Springs :: Deval Trunk Spoiler :: RAI HFC & Downpipe to Stock Pipes with Magnaflow Mufflers :: LEDs (Interior and License Plate)
Stock gap is .028 right? .032 is recommended for tuned cars. Or is the opposite true?
Well it depends on what you mean by stock but coming straight from the factory, our OEM spark plugs are actually UNDER-GAPPED at 0.027". Since OEM spark plugs were made for longevity (~50k+ miles), they were set at a lower gap because the gap will eventually get bigger through time and wear on the electrodes.
IMHO from personal experience, I believe a 0.032" gap is optimal for our cars.
Since I currently use NGK spark plugs on my B7A4 and quite familiar with them, let's go over what to look for and what to set the gaps at when using NGK as an example (the same concept can be applied to other brand spark plugs)
This is how NGK's numbering system typically works:
Most NGK spark plugs you find at your local auto parts store end with a (-xx) after the part number; which signifies a pre-gap.
For example, if you got a set of BKR7E-11's (although those are very hard to find), the -11 denotes a 1.1mm or 0.044" pre-gap. A BKR7E-8 would be a 0.8mm or 0.032" pre-gap, and so forth.. However, part numbers that do NOT have a (-xx) such as BKR7E will indicate the default gap of 0.0315" (basically a 0.032"). So do NOT get that confused.
Many people who use the BKR6E's often buy the BKR6E-11's instead since it's OEM recommended for many vehicles, which comes with a HUGE gap of 1.1mm or 0.044". In order for it to work properly with the gap you want (0.032"), you need to bang the crap out of the ground strap just to make 0.032". But by then, the strap is already crooked and bent. This will lead to more mis-fires and pre-mature wear. You typically want a spark plug that's pre-gapped as close as possible to your desired gap - best way to keep the center and ground electrodes parallel.
A general rule of thumb:
Always stay within a +/- 0.008" gap range when re-gapping. Basically, a 0.032" plug should be gapped no less than 0.024" and no more than 0.040". (This applies to most plugs using a single ground electrode strap. Multi-electrode straps are a different beast that I'm sadly not familiar with.)
Stokes|Moderator - PM me with any questions/concerns
I wish I had seen this thread before posting in the other one. One more question for you kristokes. What plugs did you have before the BKR7E's? Or maybe to better rephrase it, did you ever have the BKR7IE's and then make the switch to the BKR7E's?
I wish I had seen this thread before posting in the other one. One more question for you kristokes. What plugs did you have before the BKR7E's? Or maybe to better rephrase it, did you ever have the BKR7IE's and then make the switch to the BKR7E's?
Prior to using NGK BKR7E (copper), I used the factory Bosch spark plugs until my first oil change at approx. 5k miles. Since then, I've been using BKR7E and replacing them every oil change..
Stokes|Moderator - PM me with any questions/concerns
Prior to using NGK BKR7E (copper), I used the factory Bosch spark plugs until my first oil change at approx. 5k miles. Since then, I've been using BKR7E and replacing them every oil change..
Cool, thanks for the info. I actually installed the BKR7E's on Saturday. The engine seems to run a little smoother, but that may be because they're brand new as well. Still, once in awhile, my old NGK BKR7EIX's would cause the engine to misfire for 5 seconds on a cold start. They were all gapped at .032" so I don't know why they were doing that. My original set of BKR7EIX's never caused misfires like that until they had 40k on them. Then at wide open throttle at about 2500rpm (full boost), I'd get one misfire. It was due to the buildup on the plugs though.
I have a 2006 audi a4 non s line with 54k miles. I decided to change the spark plugs and put in the new Pulstar Iridium Series. After I installed them I started the car and it sounded a bit weird like a little knocking sound and I figured the engine is adjusting to the new supposed bigger spark. So I put it in drive and went down the street all of a sudden the car started to jerk and shutter and the check engine light came on. So I went back and checked all of the plugs and they looked fine and the coils were switched and it still did the same thing. Long story short I put back in the stock plugs and car works like a gem. Any comments or suggestions? I was thinking maybe they weren't spaced correctly but they came straight from pulstar.
^ It sounds like your new spark plugs are incorrectly gapped. Purchase a spark plug gapper from your local auto parts store and check the gap on your Pulstar spark plugs.
Spark plug gapper:
Stokes|Moderator - PM me with any questions/concerns
I've had both the stock plugs, the iridium one step colder NGK's, and now the copper one step colder NGK's. I did notice a slightly better idle with the NGK iridium's and coppers over the stock plugs, but otherwise, the performance was about the same. I'm on that forum A LOT (over 15k posts) and I've seen people say similar things. Some of my buddies stick with the factory plugs even on K04'd 2.0T's. Either way, IMO it's not a huge difference with the slightly colder plugs, but it's not hurting anything so I stick with them. FWIW, I used them in -15 degree weather with no problems starting or anything.
Changed mine out, a couple days ago. Since then all sorts of strange happenings................. Car doesn't want to start up each time, sometimes one turn others 3-4. Exhaust is smelling pretty foul, and intermittently I'm getting smoke from the exhaust yesterday it was a thick cloud of white smoke, today not as thick, but still smoke present. A simple drive around the block has the car studdering, and possibly going into limp mod (not sure about limp mode as I don't truly know all that goes into it) Before, I changed the plugs to the 7E's I had a few misfire codes. I attributed them to my plugs since the dealership changed out all 4 coils packs last year. Anyone experience coil packs going bad after just over a year? Pretty sure they are gapped right. Any thoughts?
I plan on dropping it off with my tuner, but any info is welcome.
Originally Posted by jimrobbington
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