Instead of pestering some guys individually, I thought a thread would be a good idea to get everyone's opinion in one place.
Those of you, who have tuned their 63's, what is your take regarding warranty and its possible denial? I am aware of the adage 'you pay to play' but some of the inherent issues can cost a bomb and if I am not wrong, then the bills can run upto several thousand if there is no warranty.
I am very keen on getting a tune and I hate the fact that there's something out there, which has the potential to improve the C63 upto a great degree. But I also have a MB ELW which will expire in more than 2 years. Does everyone having a tune, have a valid warranty regardless of MB or 3rd party. I was thinking of returning my warranty and keep the cash away for any eventuality but that might be a stupid idea.
I know that this topic (tune vs warranty) has been beaten to death and I have used the search function and found bits and pieces of info but it would be great if newer guys who tuned, could weigh in.
Thanks!

I have warranty and a eurocharged tuned.

If you are really worried, I know they offer a handheld device. Where you can flash your ecu back to stock when you go to the dealer. Then back to your tune when done.

At the end of the day its your decision. For me the tune is awesome and my car is a whole new beast.

yeah. I am leaning towards a handheld device. what I want to know is that whether or not they can really tell if the car's tuned and if a warranty situation comes up.

I tune most of my cars (including C63) and have never had warranty problems. I get serviced at either MB San Diego or MB Escondido. YMMV.

@MercPlease - so do you have a handheld device (or programmer) that you return to original settings?

to the OP - i have the same concerns as you do, having a CPO (I'm in the one year of the CPO, then the extended warranty kicks in onto the next years, I think I got the 2 or 3 yrs following the CPO).. anyways, my concern is that if something happens to the car, say won't start, etc and there isn't a way to return to factory settings (via handheld), and got the car to be towed to MB service and they find out there's a tune.. then what?

Remember that it's NOT illegal to modify your car. If something on your car were to fail and you had modifications, the dealership would have to prove that it was the modification that caused the failure.

I would say go for the tune if you don't have the head bolt issue to worry about because these engines are making more power in the other Mercedes AMG line-up anyway so it's safe.

Problem is i dont know if i will have the headbolt issue until it strikes. If not for the headbolt and intake manifold issue, i would have had the tune by now

As stated above just go with the eurocharged tune then. You will have a flashloader that plugs into your obd port to flip to stock tune or back. I had a giac flashloader for my gti and there was never an issue. My local vw dealer also could care less about mods and do not void your warranty due to them. Ill be going with a eurocharged tune myself in the near future. Roughly an increase of 80hp from a tune alone makes it certainly worth it.

I have had my car serviced at two different dealerships while I've had my Eurocharged tune. I've only had one issue that may or may not be related to the tune and that is my car hit a torque limit.

The dealer did a full check up on the car while the tune was applied and found nothing wrong except codes for not having catalytic converters installed. They told me I would need to put the cats back on before they could go any further on diagnosing any problems, but there were none that they were aware of.

Sadly, this isn't the court of law you're dealing with - no innocent until proven guilty. If they think your car is modified they'll simply deny it. Especially if it's something driveline related. They're out to make money. I know someone who had his warranty claim on a hurt motor denied and the reason was because he didn't come in for recommended oil changes, essentially (ford). He could have claimed he took it elsewhere but they required proof/records of that. I'm also fairly certain that if you flash your car back to stock they can still see that it's been flashed recently and they'd know it was tuned. But that being said, I'm sure you could get warranty work done without them even knowing you're tuned if they aren't out to point blame or looking for it. In short what I'm trying to say is, tuning your car can/will void your warranty, but it could very well could go unnoticed or if it's something totally unrelated, your dealership could be mod friendly enough to not care.

I'd like to actually know what protocol is if you come in with somethign like a thrown rod or even the head bolt issue. I wonder if they start digging and checking.

Good post OP!! I was always curious about this tune vs warranty as well.

And since my car engine is in the headbolts issue range, I prefer not to take a chance.

I would say go for it! Is there a tuner near you?

Personally, I would tow my car to Velos since I am local so they could tune it back to stock before towing to the benz dealership. That is, if the warranty was somehow "voided" by the tune, which it is not. I recommend making friends in the tech department at your local dealership, there will be no issues then.

Thats my concern as well and thats why I have not driven one with a tune. Dont want to know what I am missing out on :-p
there is a tuner near me who might help in case of an issue. Unfortunately, I have a 2009 which means that my car is a candidate for a headbolt failure. Granted, headbolt failures are rare and I haven't come across anyone with a headbolt failure AND a tune. but i would like to know what I am looking at if the headbolts fail on my tuned car.

My car is a 2008, the engine is within the headbolt failure range, and I tuned my car with Velos this winter.
All I can say is I was so fookin stupid to miss out on the fun in the last 4 years.
Don't think about - just get the tune and enjoy it

Tuned by Kleemann and have been happy with Cory's service. If you're worried, go with a vendor that offers the handheld device so there is no evidence of ECU tampering. If you're not tuned, you are missing out on what this engine is capable of.

Just talk to your SA? Ask him wether theyd void your warranty because of it, simple! I was worried about this before so my car was stock for longer than it should have been. Talked to my SA about catless and tune and he absolutely didnt care, ive gotten tons of warranty work since.

Sure they won't care even if you have LTH, but when an issue comes out aftermarket air filters will void your warranty

I gave him a call and he said that he didnt recommend getting a tune. He added that they can find out if they want to. But i will take that with a pinch of salt. Obviously he would want to play it safe.

Aftermarket air filters can void warranty? I mean that can happen but there's a very remote chance since they can be switched out easily.
I installed afe's yesterday and they were a piece of cake as far as installation is concerned.

I have an OE Tuning handheld since new and love it, highly recommend them. Idk if the dealer can tell or if it even matters but I always flash it back to stock before brining it in for service just in case, it only takes a minute, and I have been in for warrenty issues where performance mods should have been questioned but weren't. I do wonder if it would raise a flag taking the car past its original speed limiter, so far I've had it to 173 and the speed limiter is 174 lol

Long story short if you have a tune your car's warranty related to engine and transmission will be voided. If you have a good relationship with your SA he can help you with minor things but on major warranty issues MB will investigate your car and find out it's tuned. Make your decision according to that. I also had a tune on my C63 and if I go back in time I would do it again. It's a lot of fun and worth the risk to me.

I read about that somewhere. They can't necessarily see that you have a tune, but if you go over the original limiter or overrev, the car logs things like that. I remember reading a out one member whose SA asked how long he'd been tuned. He denied it until the SA said, your top speed is logged at over 190 mph...

To the OP. I had the same concerns as well. I bought an 09 CPO and purchased a 3rd party extended warranty.

Tuned it (Eurocharged w/handheld). A little time later, got plagued with the headbolt issue and a little time after that, got plagued with faulty cam adjusters. Both times, I used the handheld to put it back to stock before dropping it off at the dealer. Never had a problem with MB.

Thanks for your reply! your reply puts me at ease a little bit :-)

I wonder what the actual speed was? Don't you need headers to approach that speed?