nycphotography

You should "not intend" harder.

aeroman

Does this work?

SL65MONSTA

Hi Nick part number is BKR6EGP and make is NGK. From my understanding they are pre gaped to 0.04 , they also are same as the brother and sister of them the double platinum but just have a shorter life.

SL65MONSTA

please explain how I was rude, did you come on to my post being rude first ?

SL65MONSTA

explain how ?

I am not a rude guy, I actually pride who I am how i am "Being Real!, also not nasty like some people in this world! taking out my frustration on random people on forums "

nycphotography

Your other thread on this same subject was not exactly a textbook example of respect and decorum. If you can't see that, then I can't help you here. I'd suggest you go take another look.

If you really are sincere about learning to conduct yourself online with dignity, send me a PM and I will do whatever I can to coach you. Privately.

Welwynnick

Can we get away from bickering for a minute and look at facts. I know its less entertaining, but this may be the core for of the problem.

Remember what I said about using manufacturer on-line catalogues? This is what NGK say:

http://www.ngk.com/product.aspx?zpid=9329

NGK 7092 BKR6EGP G-Power Plug
http://www.ngk.com/product.aspx?zpid=9795

NGK 5648 IFR6Q-G Laser Iridium Plug
Therefore the BKR6EGP is a platinum/nickel plug that lasts 30-40k. That's fine. The factory gap is 0.039" (1.0mm), which is the gap used by the natural aspirated V8 and V12.

IFR6Q-G is an iridium/platinum plug that lasts 80-100k. That's fine, too. However, the factory gap is 0.028"/0.7mm. Both the plug and the gap are what's specified by Mercedes - see the operator's manual. Also see any other spark plug manufacturer's spec sheet for this car. They all say the same thing - 0.7mm gap.

I also made the same mistake last year. I took a retailers recommendation and fitted N/A V12 plugs, and guess what - it misfired!

Then I took all the plugs out and re-gapped them - the misfire completely disappeared.

The evidence strongly suggests that you've done exactly the same thing.

Nick

tandan

I don't think he got it.

mcguirja

An intelligent and well thought out hypotheses. Even if this wasn't to work it is a no cost option for the OP but does sounds like it may very plausibly solve the misfire he has been experiencing. Thank you leveraging your knowledge and experience Nick as well as bringing some sound reasoning and rational thinking to this thread.

James

AMG-Driver

Nick, good find!

When you look at the NGK-Homepage for SL65 recommendation is only NGK IFR6Q-G!

And I would be VERY CAREFUL ONLY to use the recommendation from NGK or MB.

NGK BKR6EGP is 2,50$ in the U.S.
NGK IFR6Q-G is around 11$ in the U.S.

Quite a difference when you need 24 of them, but I personally would never make compromises in a highly turbocharged 200K $ car, where a premium spark plug is needed.

And the GAP is indeed 0,7mm vs. 1,0mm.

I don't think BKR6EGP is the correct spark plug for this car - even if some independent dealers list them for this car.

SL65MONSTA

I installed the new plugs being BKR6EGP car ran just fine and purred beautifully at lights sitting at about 0.500rpms not fluctuating the slightest and was very responsive in the new plug change. It was only after the tune (immediately) that the misfires came up, from all the information I have received through this forum and other external people seems to be a combination of factors or could be with the extra psi placing pressure on the spark or the tune demanding longer spark times with new sparks could have fried what was already old plugs. Will regap today , clear codes and try again then repost.

** these plugs work just fine on v12s they are the replacement on the Maybachs which have the exact same engine as us. The only thing that is different is the material used on the coating one being "iridium" and BKR6EGP being "platinum" basically meaning one will last longer then the other. in terms of spark asking a plug to jump an extra 0.3mm would not blow a coil or make a car misfire. Highly unlikely

Think about it this means if one or two plugs fail or need replacing this will blow out both your coil packs, this is very highly unlikely. Especially at $5000 a pop each side I'm sure they never created them that delicate, furthermore they lasted for 12 years , 100,000kms I'm sure with in that time there must have been at least one misfire or spark fail, etc it wouldn't blow out a coil pack or IGN module.

Welwynnick

Whoever told you that BKR6EGP were the right plug for SL65 (or Maybach) gave you some bad information. Retailers often get part numbers wrong; you can only trust manufacturers. Here is the evidence:

1) If you haven't done so already, go to the MB Owners Manuals page and download the SL manual, page 428 says NGK IFR6QG 0.028" (0.7mm) for both the SL600 and SL65:

https://www.mbusa.com/mercedes/servi...class=SL-Class

2) Go to NGK part finder and enter Spark Plugs, Mercedes Benz, SL64 AMG, 6.0, and it returns IFR6Q-G :

http://www.ngkpartfinder.co.uk/cars_...AMG&engine=6.0

3) Go to this part finder and enter AUTOMOTIVE, YEAR, MERCEDES BENZ, SL65 AMG, 2DR CONVERTIBLE, V12 6.0, AND IT RETURNS 5648 / IFR6Q-G


http://www.ngk.com/Spark-Plugs-NGK-c593.aspx

4) Download this PDF catalogue and look for your car, and it will list 5648 IFR6Q-G:

http://www.ngkntk.co.uk/wp-content/u...w-cat-2015.pdf

NEXT, do exactly the same for any of the Maybach models, and they will all return NGK 5648 IFR6Q-G as well.

It makes no difference whether its the 5.5 or the 6.0 engine, not whether the model is S, SL, CL or Maybach. If its a V12TT engine, the recommended spark plug is the IFR6Q-G, and the gap is 0.7mm. It specifies the gap in the owners manual - all the owners manuals.

Does 1.0mm vs 0.7mm make any difference? Yes it does. 1.0mm is the right gap for the NA engine, and 0.7mm is the gap for the TT engine. I've proved that, and you've proved that. When you increase the gap, you increase the voltage required to spark. When you increase the compression pressure, you increase the voltage required.
It's called Paschen's Law - look it up:

https://en.wikipedia.org/wiki/Paschen%27s_law

Its quite clear that you got some bad advice and fitted the wrong spark plugs with too big a gap, AND THEN you had a tune that increased boost pressure (which if anything would require a SMALLER spark plug gap, not a bigger open). Bigger gaps and higher boost put more load on the coil pack because it needs to generate more voltage to generate the spark. Does 0.3mm make that much difference? Yes, definitely.

Nick

SL65MONSTA

you seem very confident it is the gap on the sparks hahaha, I wish it was I really do, just about to test now, regaped and everything back in. I personally think its the IGN module if not both coils and the IGN

AMG-Driver

Of course 0,3mm can make a difference.

When a spark plug is at the end of its life you often have too big of a gap - resulting in misfire.

If I were you - I would change to IFR6Q-G, not regap the BKR6EGP. Believe me, sooner or later you will get new problems.

If you are lucky - maybe the fault is away with the correct Spark Plug, at a margin of 250$ + labour or maybe you have a friend who can make the work.

SL65MONSTA

I've seen sparks jump centimetres , to say that a gap of 3/10ths of a millimetre can blow a coil pack or cause a misfire is far fetched. AGAIN! the car ran fine with the plugs as they are, also re-gaped them to 0.7mm from 1.0mm just as I thought same outcome. Everyone is pointing to everything else but my tune installed ? hahah

tandan

WOW!

Welwynnick

Yes - at atmospheric pressure.

But when the engine is under load and under boost, the compression pressure will be hundreds of PSI, and then it will not spark.

You may have more than one problem.
You may have damaged your coil packs.
You may have damaged your ignition supply
You may not have damaged anything.

But regardless of anything else, you have the wrong spark plugs.

Nick

AMG-Driver

Nick hit the nail on the Head

HaHaHa...

AMG-Driver

One other thought:

In my opinion even the Iridium/Platinum Plugs are not good for 80/100K Kilometers in this V12 Biturbo. The service intervall at MB is 60K at latest - and based on many observations in boosted cars, also MB, the plugs often look real bad at the end of the service intervall.

So take the best you can get, to minimize your problems. Otherwise you might pay 2xtimes if you have to change the plugs again.

Welwynnick

Are you saying that you have now re-gapped all 24 spark plugs to 0.7mm, and taken it out for a test drive, and despite that, it still misfires?

Nick

SL65MONSTA

and AGAIN!!! the spark plugs that were put in the car worked just fine , car purred like a baby and went even better! tell me its the sparks again ahahhaahha ^^^

AMG-Driver

Monsta is a hard nut to crack ,as we say here in Germany - its funny

It does not sound that you put the old plugs under much load over the last 500 KM - I think now with the tune they have seen real boost for the first time.

How fast can you drive in Australia? How long under boost?

I would say they would have failed even without a tune not too far away...

aeroman

You put those cheap sh*t plugs in this level of performance car? WOW That is telling of how you may have maintained this car. Going cheap on an SL65 is not wise.

SL65MONSTA

actually quiet wrong, I dont skimp (go cheap) on parts all fluids , oils, parts are of the best quality. NGK is not a cheap quality part, the difference is actually in longevity, do I intend to keep this car for another 100,000kms like the plugs suggest I dont really think so. Why would you pay triple the price for plugs if your going to be getting a SLS in a year ?

They dont sell plugs and write on there site they are suitable for Maybachs and Mercedes v12 engines if there not suited to them, this in itself is a lawsuit ! I could potentially sue NGK and get compensation on the damage the plugs created, but it isn't the dam plugs ! I am the one who put the plugs in , I am the one who drove the car with the new plugs in, and I am the one who saw how the new plugs performed! So quit trying to blame plugs that are perfectly fine and made for v12 M275 ! Really you people do not read previous posts, IT IS NOT THE PLUGS! THIS HAPPENED AFTER INSTALLING TUNE!!!!!!!!!!!!!!!

IT IS NOT THE PLUGS! THIS HAPPENED AFTER INSTALLING TUNE!!!!!!!!!!!!!!!
IT IS NOT THE PLUGS! THIS HAPPENED AFTER INSTALLING TUNE!!!!!!!!!!!!!!!
IT IS NOT THE PLUGS! THIS HAPPENED AFTER INSTALLING TUNE!!!!!!!!!!!!!!!
IT IS NOT THE PLUGS! THIS HAPPENED AFTER INSTALLING TUNE!!!!!!!!!!!!!!!

Welwynnick

Where did you buy them from?