I unfortunately threw my back out a few days ago so no new progress on the MG, but I did replace the thermostat in my Volvo over Easter so I figured I'd throw this video up now. I was getting a check engine light and when I pulled the codes it gave me P0128 code. After doing some searching on the interwebs that translates to "Coolant Temp Below Thermostat Regulating Temp". From the looks of it most people replaced their coolant temp sensor first which did not fix the problem, then they went for the thermostat which did fix the problem. I figured I'd cut to the chase and just go right for the thermostat and sure enough that fixed the problem and only cost me $10.
