V12TT - Update after tune and few months of driving
Thread Starter
MBWorld Fanatic!
Joined: Jan 2007
Posts: 1,986
Likes: 9
From: Toronto
V12TT
V12TT - Update after tune and few months of driving
Got it tuned this year in January. Right after the tune, as expected, car started misfiring badly. Was told it was the transformer so I changed that out but still misfired. Changed out the 24 spark plugs with OEM NGK plugs from the dealer as well as the drivers side coil pack and NO misfire.
This car is a undefeated rocket ship.
However, it started misfiring again this month. This time random misfire, mostly on cylinder 5 (what's up with cyl 5 misfiring on S600's???) so I changed out the coil pack as it's only been 10,000kms on the new plugs I thought. Misfire again with the new coil (passenger side this time).
Pulled out the plugs this is the condition of a tuned V12 plug after 10,000kms of hard driving.
Keep in mind each coil here costs around $1500, transformer is $1500 and 24 plugs are $400. This is some serious maintenance, thinking of going back to stock or doing a dyno-tune, I just want to extend the life of the plugs and coils as I don't want to change them each time I change my engine oil.
This car is a undefeated rocket ship.
However, it started misfiring again this month. This time random misfire, mostly on cylinder 5 (what's up with cyl 5 misfiring on S600's???) so I changed out the coil pack as it's only been 10,000kms on the new plugs I thought. Misfire again with the new coil (passenger side this time).
Pulled out the plugs this is the condition of a tuned V12 plug after 10,000kms of hard driving.
Keep in mind each coil here costs around $1500, transformer is $1500 and 24 plugs are $400. This is some serious maintenance, thinking of going back to stock or doing a dyno-tune, I just want to extend the life of the plugs and coils as I don't want to change them each time I change my engine oil.
Senior Member
Joined: Oct 2004
Posts: 471
Likes: 33
From: Germany
SL65 R230
Thanks for your feedback. There is something wrong for sure. lean issue? Although the plug looks very dark the electrode seems to be really melted?
Can you please tell us a little more about your modifications, only ECU-Tune?
Can you please tell us a little more about your modifications, only ECU-Tune?
Last edited by AMG-Driver; Jul 2, 2014 at 03:10 AM.
Thread Starter
MBWorld Fanatic!
Joined: Jan 2007
Posts: 1,986
Likes: 9
From: Toronto
V12TT
ECU/TCU tune, cat-less downpipes and 3" exhaust. Smells horrible even inside the cabin after a full throttle run. Of-course, this is only a bench tune. I'm not convinced if there is something wrong, or perhaps a sacrifice rather to have massive amounts of power vs sooner maintenance (especially turbo'd tuned cars). Power is there, also fuel economy and exhaust tips usually cake over to black.
Senior Member
Joined: Oct 2004
Posts: 471
Likes: 33
From: Germany
SL65 R230
From my experience with an ECU-tune the Plugs should not look that bad after 10.000 KM.
On my old SL600 with ECU-Tune we also changed the Fuel-Pump to the Sl65 Pump to be safe on Highspeed runs on the German Autobahn. Don't know if this effects also your driving-cycles, but the 65 pump has more capacity than the 600 Pump.
I would also check IAT, because if they are too high, the ECU possibly can not pull back enough timing with the ECU-Tune. But you say the car is running strong, so that might not be the problem.
For the smell in the cabin, is there a downpipe/exhaust leak?
On my old SL600 with ECU-Tune we also changed the Fuel-Pump to the Sl65 Pump to be safe on Highspeed runs on the German Autobahn. Don't know if this effects also your driving-cycles, but the 65 pump has more capacity than the 600 Pump.
I would also check IAT, because if they are too high, the ECU possibly can not pull back enough timing with the ECU-Tune. But you say the car is running strong, so that might not be the problem.
For the smell in the cabin, is there a downpipe/exhaust leak?
Last edited by AMG-Driver; Jul 2, 2014 at 05:16 AM.
MBWorld Fanatic!
Joined: Mar 2009
Posts: 2,630
Likes: 9
From: Chicago
W215 V12TT Build by Speedriven, W221 S550 4Matic
I believe the Coils will last once you put the new ones in. They are good for some miles, plus they are way cheaper now than they use to be back in the day. I'm going to Speedriven today to scan the car after work for my current misfire issues. If I'm doing the coils which 99% of the chance I am I will go ahead and do the plugs as well on the car that way I can take a pic of what mine look like. The car probably has around 5K or more miles on the tune for sure. The other mods maybe 1K miles or so.
Trending Topics
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Jan 2011
Posts: 1,181
Likes: 59
CL65
OP, how many miles on your car? What do the other plugs look like? I would think a box tune would treat all the plugs the same. Shardul, do you think the amg set up of spraying the cylinders with oil helps with the scoring or just delays the inevitable?
Former Vendor of MBWorld
iTrader: (1)
Joined: May 2008
Posts: 12,139
Likes: 295
From: Houston
2003 W211 E55, 2003 W220 S600
Senior Member
Joined: Jul 2011
Posts: 386
Likes: 12
Cl65 AMG
That's oil, and rich.
I have to wonder If its too rich ? Any engine can pass oil by the rings, normally its one or two cylinders (V12 maybe 3). If all look like that investigate other areas of leakage. Guides, intake gaskets, PCV etc.
IMO
I have to wonder If its too rich ? Any engine can pass oil by the rings, normally its one or two cylinders (V12 maybe 3). If all look like that investigate other areas of leakage. Guides, intake gaskets, PCV etc.
IMO
Senior Member
Joined: Oct 2004
Posts: 471
Likes: 33
From: Germany
SL65 R230
Yes its rich, but does the electrode really melt with rich? Maybe here are 2 things cumming together. Rich from normal driving or oil deposits and an additonal lean issue on WOT. Most important is to look at the the other plugs...Good luck!
Senior Member
Joined: Aug 2013
Posts: 296
Likes: 2
From: NE Minneapolis, MN
2006 CL65
Just do a compression check for us or if you have access to a cylinder leakage tester. I would love to see your results. Then we can stop speculation. Oh and after you look at all the plugs.
MBWorld Fanatic!
Joined: Feb 2004
Posts: 9,155
Likes: 20
From: Southern, CA.
V12-Biturbo
Also get it Dyno tuned vs box tuned, you mentioned having catless dwn pipes this will effect tune (to the LEAN side, I know we're talking about very possible RICH condition, but those melted sparkplugs scream LEAN too)
PLATINUM SPONSOR
Joined: Jun 2008
Posts: 3,834
Likes: 65
From: Texas
2003 CL55
Just do a leakdown test before anyting esle, to amke sure engine compression is ok and no further damage.
__________________
E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
www.ultimatepd.com
instagram @ultimate_pd
facebook.com/ultimatepd
E63 Biturbo, UPD Cold Air induction kit, UPD performance crank pulley and UPD adjustable rear suspension with ride height adjustment.
CL55 UPD Cold Air Boost kit, UPD 3000 stall converter, UPD 77mm SC clutched pulley and beltwrap kit, Custom long tubes, UPD crank pulley , UPD suspension kit, UPD SC pulley, Aux. HE, Trunk tank w/rule 2000 pump, Mezeire pump, UPD 5pc idler set, Aluminum rotor hats.
www.ultimatepd.com
instagram @ultimate_pd
facebook.com/ultimatepd
