[CT335xi]

Originally Posted by Picasso

Yep. Tune is way too aggressive, higher boost blows spark plugs, while 93 octane isn't good enough for the timing that Stage 2 tune uses. yes it does dial back timing, but remember that knock sensor isn't as fast to completely save you from knock. Knock happens first and only then tune will dial it back. Most of time it works, until it's not. And then you get bent rod. Here's what will happen when rod is bent: you'll get the usual malfunction lights and warning. You'll stop and restart thinking it will go away, only it will not go away. Engine will work like it still has a misfire and it will have that light vibration. No matter of reflash or going back to stock will make it go away. After that you'll go to the shop asking to check spark plugs or coils - hoping it's not rod knocking. They will quickly pop the oil cap and use boroscope to check cylinder walls and ............. BAM - you have a scorched cylinder wall and engine is done. Your mind will realize you are fucked $$$$
You'll try to frantically think how to scam dealership to make it look like it's not your fault lol. You'll have to change all spark plugs back to stock ones (hopefully you didn't just throw them away did you? And nope, putting new ones will only cause even more suspicion). Then you'll try to flash it back and lock it like BM3 says lol. It might work, until it won't. Dealers have 100% way to find out and bust your sorry ass for lying to them. You can even reset flash counter lol and reset all red flags like speed limiter, max boost etc. There's a small chance a dealer who doesn't care might not go looking deep into it. However, if they do - you are looking at the long block with labor. That's probably more than your sorry X5 costs right now. Yep, this is the reality of new BMW long block price for n63tu and labor (which isn't cheap). All that you'll have you do while car is still running 10mph with bent rod. becuase if it's not - you'll be calling tow trucks like Uber for every move lol.
And then sitting tired in the evening and thinking of options left and how much $$$$ you just thrown to garbage and still have no car that even runs lol - you might come to conclusion that maybe just maybe it wasn't worth it to play macho with your 5500lbs SUV that isn't beating any records to begin with anyway. Like for what? To impress some Ford Mustang owner lol? Come on man.
Moral of story: Stay with Stage 1 and be happy.


P.S. And nope, there aren't any other forums that have more info on n63tu.

Dude why such the negativity? I’m sure most these guys running tunes know the consequences, it almost seems like you want the guy to blow up his engine . Relax and enjoy your stock tune , but can you stop with negative comments already.