Changed my spark plug gap & OMG

[PluschakovP]

DO NOT BUY THE ROUND SPARK PLUG FEELER GAUGE

Buy actual feeler gauge strips.

So I replaced my plugs like 4k miles ago, and I was getting misfire codes in cyl. 5 & 6 often times, before and after the swap. The misfires got a little better after I put in my new NGK BKR7E plugs, but still just ever so slightly noticeable. So I went and got me some good feeler gauges, because the round piece of hunk I got from O'Riley's sucked really bad. Pulled all my plugs, and when I checked they were at .035 - .045! I was shocked. I regapped them to about .032 and let me tell you, the difference is night and day. The way the engine purrs now is unbelievable. Huge difference.

I'm thinking I'm going to gap them today to .028, because I've heard it's even better at that gap so, we'll see how it goes.

Take it from me, the gap difference of just a few thousandths makes a big difference, so get it right, get good gauges.

[vandelizer]

Thanks for this! I bought the same piece of crap round gauge and I am not sure they are gapped properly either.

[PluschakovP]

Thanks for this! I bought the same piece of crap round gauge and I am not sure they are gapped properly either.

I'm officially gapped to .028 on BKR7E plugs, non-chipped. Car is running great. With the real feeler strips it's so much more accurate to tell what gap you're actually setting. I picked up feeler strips at O'Riley's for $6. 32 feelers, all the way from .0001-.035.

[redneck truck]

I was under the impression the iridium and platinum spark plugs are not meant to be re-gapped. Is that no longer the case?

[vandelizer]

Sure enough, they weren't gapped properly. All were off of the mark by .05 or more. Big difference now at start up, quick start up and smooth. Also to redneck truck, you have to even gap the platinum ones

[AudiGman]

You must be dealing with a single ground plug. How could a flat blade feeler gauge work with multi-ground plugs?

Mine calls for a NGK BKR6EKUB. Round feeler is the only way I can see verifying the gap. You raise a very good point though. Had assumed the plugs were pre-gapped. Shame on me. Time for a change anyway.

Thank, Tom G

[-C5-]

i just installed new ngk iridiums a few weeks ago.
i didnt gap them because every single employee at the parts shop swore they didnt need it.

the car is starting and running ok, but acceleration is weak. same as with old plugs.

do you guys think its safe to pull them out to regap them? or should i leave them alone?

btw i dont get CEL's, i just replaced my old plugs due to what i thought was lacking power.

[redneck truck]

Did your old plugs look any different from your new plugs?

[PluschakovP]

What's the difference between BKR6E and BKR7E if both are from NGK?

[AudiGman]

Direct from NGK's website.. http://www.ngksparkplugs.com/techinf...stallation.asp

6E and 7E will differ in heat range typically.

Since the gap size has a direct affect on the spark plug's tip temperature
and on the voltage necessary to ionize (light) the air/fuel mixture, careful attention is required. While it is a popular misconception that plugs are pre-gapped from the factory, the fact remains that the gap must be adjusted for the vehicle that the spark plug is intended for. Those with modified engines must remember that a modified engine with higher compression or forced induction will typically require a smaller gap settings (to ensure ignitability
in these denser air/fuel mixtures). As a rule, the more power you are making, the smaller the gap you will need.

A spark plug's voltage requirement is directly proportionate to the gap size. The larger the gap, the more voltage is needed to bridge the gap. Most experienced tuners know that opening gaps up to present a larger spark to the air/fuel mixture maximizes burn efficiency. It is for this reason that most racers add high power ignition systems. The added power allows them to open the gap yet still provide a strong spark.

With this mind, many think the larger the gap the better. In fact, some aftermarket ignition systems boast that their systems can tolerate gaps that are extreme. Be wary of such claims. In most cases, the largest gap you can run may still be smaller than you think.

Tom G

[AudiGman]

One additional piece of info from NGK .. note the number suffix relating the factory gap .. http://www.ngksparkplugs.com/techinf...tnumberkey.pdf

[Siricospeed]

In response to the "pregapped spark plug." We would all like to assume that the spark plugs left the factory at the specified gap, then made it through the trucking to the port, where they were loaded on a ship, then to another port. Then another trucking company pics them up and brings them to a distributor. From the distributor to the wholesaler. From there to the retailer. And finally to you.

Do you think for one moment that they were not jostled around? Do you think the guy at the factory checked each one? CHECK EACH GAP! I have seen more messed up plugs out of the box than you can imagine! Check for cracks in the porcelain. Check for messed up threads. Check that the ground electrode is welded on properly. Check that the top is screwed on tight. And finally, put a dab of antisieze on each one so they don't get stuck in the head!

[A62TURBO]

In response to the "pregapped spark plug." We would all like to assume that the spark plugs left the factory at the specified gap, then made it through the trucking to the port, where they were loaded on a ship, then to another port. Then another trucking company pics them up and brings them to a distributor. From the distributor to the wholesaler. From there to the retailer. And finally to you.

Do you think for one moment that they were not jostled around? Do you think the guy at the factory checked each one? CHECK EACH GAP! I have seen more messed up plugs out of the box than you can imagine! Check for cracks in the porcelain. Check for messed up threads. Check that the ground electrode is welded on properly. Check that the top is screwed on tight. And finally, put a dab of antisieze on each one so they don't get stuck in the head!

+1 I installed plugs in my car once without checking the gap and the car drove like shit. When I pulled the plugs to check them they all were off by a lot, lesson learned I check them every time now.

[PluschakovP]

One additional piece of info from NGK .. note the number suffix relating the factory gap .. http://www.ngksparkplugs.com/techinf...tnumberkey.pdf

so in short, do we want to run hotter plugs or colder for our 2.7's? 6 or 7?

[AudiGman]

Use the recommended spark plug for your engine...go onto NGK's website and locate for your year/engine/vehicle .. http://www.ngksparkplugs.com/part_fi...uv/default.asp

Don't assume what is installed in your vehicle is correct. I don't recall how many times I've pulled plugs only to find the wrong one installed....go by the "current" factory recommended plug.

Tom G

[Audi0s]

Ive seen on many occasions explicitly stated on the box do not gap. I think those were single electrode platinum or iridiums. Something about breaking the tip off is possible while gapping, and would ruin the plug. The tip is much more fine. Ive never gapped the 3 or 4 electrode ones, will check them tomorrow at work though.

Awesome links btw, I liked the plug decoding chart,

[pit viper]

Always check the gap. If it's a fine tip, you just have to be very careful adjusting it.
If you're running more than 80-100 hp over stock, consider going one range colder on the plugs.

[AudiGman]

More good info from NGK.....http://www.ngk.com/faqmain.asp

The FAQ's include gaping Iridium plugs and heat range considerations..worth bookmarking!

Tom G

[PluschakovP]

So it's always safer to err on the COLDER side. So in NGK talk, the higher the number, the colder the plug. Looks like I'll get rid of the BKR6E's and stick with the BKR7E's since they seem to be performing very well in my engine.

[AudiGman]

Did you check NGK's recommended plug for your engine? FYI....don't know your year but an '01 2.7 turbo comes up requiring Part Number: PFR6Q which is their laser platinum plug.

Your car though, I guess you can run what ever you want.

Tom G

[AudiGman]

Quick update...picked up NGK Iridiums today. OEM A6 spec calls for .032...every plug was off at .028. Regapped to .032 and in they go on Friday.

Repeat to self, I will always check my plug gap..:).

Anyone figure out if the factory gap on the multi-ground plugs is on?

Thanks for the good discussion guys.

Tom G

[PluschakovP]

Quick update...picked up NGK Iridiums today. OEM A6 spec calls for .032...every plug was off at .028. Regapped to .032 and in they go on Friday.

Repeat to self, I will always check my plug gap..:).

Anyone figure out if the factory gap on the multi-ground plugs is on?

Thanks for the good discussion guys.

Tom G

OEM specs for my A6 is BKR6E plugs gapped at .032.

I bought NGK BKR7E plugs, gapped to .028, and am now getting 20.5 mpg (tried on full tank with spirited driving).

I was previously getting 16-18mpg...

[Calimus]

I brought my BKR7E's to .030 and have been happy thus far, but might pull and re-gap them at .028 for giggles and see what happens. Being that I'm chipped, it will be interesting to see if it has any change in the fuel mileage.

[PluschakovP]

I brought my BKR7E's to .030 and have been happy thus far, but might pull and re-gap them at .028 for giggles and see what happens. Being that I'm chipped, it will be interesting to see if it has any change in the fuel mileage.

I think that you will feel a difference since you are chipped. I wonder how it would be with a .026 gap or .024? There's a line I bet to where it would start to misfire due to too little gap right?

[Calimus]

you are correct. too little of a gap doesn't allow a proper burn.

[Emilgevor]

I've been meaning to change my plugs before winter and wanted to know what is the heat range I should be looking for? NGK said their plugs higher # means colder plug and I am stage II.

[VJ's A6]

I am getting misfires during cold starts, I want to check the gap over the weekend.

Which gauge tool do you guys use, the coin dial or the metal strip?

[AudiGman]

This might help. NGK has a whole series of spark plug vids on YouTube...TG

http://www.youtube.com/watch?v=lk70oyUEftY

[Emilgevor]

Found this little tool. Kinda cool but not sure how useful it would be?
Thoughts?

http://www.zaptester.com/

[Siricospeed]

Found this little tool. Kinda cool but not sure how useful it would be?
Thoughts?

http://www.zaptester.com/

Useless, unless your plug is broken in half! Just about any plug will fire with enough voltage with no compression. Compression increases resistance. Boost amplifies resistance, so a healthy ignition system is important in a turbocharged or supercharged engine.

[PluschakovP]

I am getting misfires during cold starts, I want to check the gap over the weekend.

Which gauge tool do you guys use, the coin dial or the metal strip?

Get the strips ( the feeler gauges). The coin type dial is garbage.

[audifirst]

just update after reading this post, I decided to check my NGK spark plugs (single prong) on mine v6 2.8 engine and they were off, mine were 0.038, so I have re gaped to tight .032 as per bentley

and notice quite few improvements
- quick startup
- engine rpm dropped from 900rpm to 820rpm at idle engine runs quieter
- no more engine hesitation
- smooth acceleration (usually when I speed up engine had to down shift to get some power now it increases to higher rpm and then changes the gear)
- huge hwy improved fuel economy, just did almost 1250 km (780 miles) on two tanks usually I had to refuel 3-4 times on this trip ,
usually on hwy I was getting avg 12 l /100 which is 18 MPG , now it came to avg 9.1 L/100 to 26 MPG which is awesome
I will drive in city more and will calculate the improvements which should be much better

I have order new set of spark plugs mine are overdue changed them almost 4 years ago,
thanks for this post

[Emilgevor]

I'm going to be working on my boost leak this week and wanted to regap and replace plugs. Since i am stage II I need colder plugs am I correct? What is a good NKG plug for me?

[redneck truck]

I've got BK6REQUP plugs in mine, and they're pretty dirty. I've got a bronze wire brush - is it ok to clean them with that?

[AudiGman]

Latest update...changed plugs Friday evening. Installed NGK Iridiums. Engine starts quickly, is running smooth as ever with no flat spots under acceleration. All plugs needed to be first gaped to OEM specifications.

Interestingly, the dual electrode NGK's I pulled had 27K miles on them and all measured gap in excess of .050. Most likely they were not gaped correctly out of the box (shame on me). At the same time, they could not have been that far off so 27K miles is too long a change interval when using non-precious metal plugs in spite of what the manufacturers claim.

In response to Redneck... the only plugs I have ever cleaned were for a lawn mower. Correct gap is what is most important. How many miles are on them? Use that as your guideline.

TG

[redneck truck]

I would not be surprised if the plugs had 145k miles on them. I have to ask though - if it doesn't matter if they are dirty, why bother with special metals to improve conductivity? Also, how do you suggest I go about gapping those plugs?

[Kievskiy]

siht, this thread is good, i went and bought a feeler gauge, and new plugs, now is time to gap' em and install :) thanx OP

[Chopstixs]

Anyone else have issues finding BK7RE's? I'm in the MD/DC/VA area, and everywhere I go they say they are discontinued.

[redneck truck]

Few dozen in stock at local o'reilly auto parts. Want me to send you some?

[Chopstixs]

Few dozen in stock at local o'reilly auto parts. Want me to send you some?

Sweet!! Lmk how much they are