I have 06 lsj 45k bought new low miles in account of all the issues. Fist clutch out at 20k dealer replacement out again 28k, after that put my own stage 2 aluminum flywheel no problems sense. Warped front rotors 2x leaking calipers, btw Gm install stage 2 supercharger kit with cold air intake. Back to problems. Broken sunroof, interior **** boot, and pair chipping, electric steering pump, intercooler, and radiator leaked at one point, e brake nut keeps back off, driverside door wouldn't open or close had to replace locking mech. Now currently my issue is losing coolant 1ltr. A week no visible leaks replaced thermostat, all condensers, surge tank, water pump, heater core, bleed cooling system still leaking somewhere, no water in oil engine runs at 170-180 unless idel ling time which fans turn on at 230. Been losing coolant 5 months, engine boost fine 13.5, no cel, good compression did hc test on reservoir stayed blue. So I have no idea, any suggestions???

 

coolant system pressure test

send oil sample for analysis

check plugs for evidence of coolant in chamber

check O2 sensor for coolant contamination