greekviking

Has anyone with the V12TT experienced misfire codes under load around 5-6K rpms? My car is an '07 has 61K miles, ran like new. Now whenever I get on it, it throws misfire codes and the motor idles rough. I turn it off, restart and everything is back to normal ?!? What could cause this ? Could it be a dirty fuel filter, MAF sensor, O2 sensors, etc. ..or is it a coil pack. One could spend endless amount of money and time on this and the problem most of the time does not go away. If it was a coil pack, wouldnt it be doing it at any rpm level.? I'm really stuck with this on.
I appreciate anyone with any help. Thanks.

jagata

I do not own a v12 but my v8 had a bad rod position sensor that felt like a misfire, maybe the 2 engines share that same part?

j21importer

i have experienced this problem caused by a coil pack. you should have the codes pulled to see what comes up

greekviking

If I use Star DAC, will it pinpoint the problem or just give you codes? A good possibility is that it could very well be a coil pack if the codes show only one side of the motor. Did anybody get misfire codes from both sides of the motor? I doubt that both coil packs are shot.

nick 55

Does it happen pretty consistently in 3rd gear? Right around 5600RPMs?

Nick

greekviking

YES!! Its happens in 3rd gear around 5500 rpms!!? Did you have a similar condition? What could it be . I thank you in advance.

nick 55

I'm going to guess you have a valve floating. You probably have a misfire on one cylinder that doesn't occur under normal driving, but as soon as you wind it out in third gear, it starts making a sound like a really crappy running Dodge Viper. On a good note, the parts are cheap, I would replace all three valve springs on the offending cylinder. Labor-wise, you need to find a good V12 tech, because the average dealer tech will want to remove the cylinder head(which involves removing the engine from the car). I've done 2 V12 cars that had the same issue, but one did it at 3k miles, the other at 17k. Let me know if I can help you out any further.

Nick

nick 55

Any updates GV?

Nick

greekviking

Yes. It was a vacuum hose that was causing the misfires. It looks like the small hose on the right side of the engine was dry rotted a little, came loose, and had a leak. Why didnt MB use silicon hoses? why cheap out and go to rubber? I guess typical OEM stuff....but problem solved. Always check vacuum lines in turbo motors, one leak could cause major problems.

V12Godspeed

This person scammed me out of 105.00 Dollars, supposedly selling some V12 emblems...I have replied thru various e-mails asking for tracking info...it is the time of day I have not heard from him nor received package.

I will post this in every single forum if i have to and report it to the moderators.

As of this point I am opening a Paypal case for my 105 dollars. If he offers to sell you something beware, you have been warned.