No, but if you're using a custom kernel, you'll brick the phone.
Totally Right, check very well what are you have on your phone then do what you want to do. Relock Bootloader can be possible with Stock Kernel only.
IF I HELPED DO NOT SAY THANKS, CLICK IT. My Evolution: Sony Xperia Z1 - UB + 4.3 Rooted + Deodexed, HTC HD2, HTC Diamond 2, HTC HD Blackstone, Nokia 7070 Prism, Qtek 9100, Nokia 3100, Motorola T720i, Nokia 3310, Sony Ericson PF 768 (Blue)
How Get Root on Sony Xperia Z1 with Locked Bootloader and the Latest Android 4.4
A Web browser is one of these applications that we can’t live without. We useit … more
20 Sep 2014
By Tomek Kondrat
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?