How's my spark plugs?

A6 All/ S6 All
#1

Im an Audi noobie, still learning, i had some spare time after work today so i pulled one of the plugs to check condition.

I pulled the easiest one front right of the engine bay. Here’s a how it looks.

http://i.imgur.com/0g18QM1.jpg

http://i.imgur.com/CBkPoWy.jpg

Mileage is about 68k and they were changed 20k ago according to the service history, There was a bit of oily residue on the threads and brown tip? to me that seems like dry fouling? Ill probably order up a fresh set of NGK ones and swap them out.

I am planning to get the carbon clean done soon, its probably best to swap them while the manifold is off or should i leave some miles between carbon clean and new plugs ?

#2

I don’t know much about plugs either, so I can’t tell if it looks ok or not. But I do know that oily plugs can mean bad valve cover gasket, and if that’s the case, it’s probably easiest to replace those gaskets while the manifold is off. So if you’re getting a carbon cleaning done anyways, I think if it were me I’d wait to put the plugs in until everything else gets looked at/cleaned/repaired. Or if it’ll be a while before the carbon cleaning, maybe replace the plugs both now, and again later if they need it, since they don’t really cost that much ($130 @ JHM)

#3

Yeah i only took one out and as i said i dont know enough about these cars yet to know about this!

It looks like its cheaper for me to buy the parts from the US than locally here!

Are ECS tuning good for v10 parts?

#4

I haven’t bought from them, but I believe so. I forgot you were overseas haha! Seems to be the way it always goes, you guys have better parts availability, we have better pricing :wink:

#5

Economies of scale i guess! I think there is 2 s6 v10’s in the country, mine being one of them!

#6

Try JHM they usually beat most prices

https://jhmotorsports.com/shop/catalog/spark-plug-ngk-laser-platinum-tri-electrode-oem-for-b8-s5-42l-v8-and-s6-s8-52l-v10-p-2572.html?cPath=21_360_361

#7

As for your plugs Ill be honest that dosent look good. It looks like rust that would suggest water or lots of condensation in the cylinders. unless you ran some odd fuel that left build up on the plugs I would suggest pulling some different plugs and seeing what they look lilke

#8

Yuck, swap those ASAP :slight_smile:

#9

That plug is definitely not looking good. Did the car sit for a long period? Do you have ethanol in your fuel? A good burning plug should be light brown color. Not sure what would cause the rusty color, looks like you need to pull them, the condition of the other plugs will give you a good view of how your fuel/intake system is performing.

#10

The car was sitting for long periods since i have it, since november, it was a second car for previous owner so maybe it was sitting a week or two at a time. i drive it daily but its only a short 9 mile trip to work each way We should have 5% ethanol in our fuel over here.

I managed to find some plugs for a good price from Germany so have a fresh set on the way

#11

Have you or the previous owner used octane booster? MMT will cause them to color like that. Rust typically forms unevenly and that plug appears to have a uniform coating on the electrodes and insulator.

If the engine has seen octane booster then all the plugs should look that.

#12

yes i run it on octane booster to help improve the fuel quality she gets :slight_smile:

#13

Good call D Lo very true MMT leaves a nasty rust build up.

Buddyboy the best way to know more of what the cause is… is to put of the pictures of the other plugs when you pull them. That will help tell more of what it could be. If it is MMT build up you might want to look for another additive as MMT will also take out our cats after a little while

#14

I have a new set on the way so ill check them all when they turn up. This is the booster i use:

http://www.nfadditives.com/Products_Octane-Boosters.php

I Use the NF Race one

Im not sure what MMT means? Is that an additive in the booster? This one says its o2 sensor and cat friendly

#15

MMT is an additive used in very strong boosters.

#16

Based on their FAQ I would say it includes MTT

http://uploads.tapatalk-cdn.com/20160825/178ae1e8eac831f59d7d2fafc5fba888.jpg

#17

Thanks for the info. im only using 100mm per tank so i wouldn’t say high usage, there was one tankful i may have put a full bottle in too see if it made any difference. Ill probably just use up the last few bottles i have and try something else.

New plugs turned up, whats the optimal spark plug gap for these bad boys?

#18

Check the gap but I think its .38 let me know what they came pre gapped at.

#19

when you say .38 are you referring to in milimeters? :slight_smile:

#20

I think it’s .038 inches. I have no idea what the gap is supposed to be, but if it’s what Justin thinks it is then I believe that’s the unit of measurement.

If you pick up a spark plug gapper it should make it easy:

http://cdn.instructables.com/FIS/G3PQ/H3Z3UG9I/FISG3PQH3Z3UG9I.MEDIUM.jpg