my outside temp gauge does not light up on my merc w210v8 what could be the problem

ken mitchell, November 2008

hi i have a problem been told by aa head gasgit gone put in garage rad was blocked so new rad put on and new thermostat had water pumped checked the man tested again and reckons not head gasgit would anything else cause this over heating within mins and back pressure its a 28v6 vito

colin dey, August 2009