Im nearing 100k on my 2007 mcs and am getting a p0128 code. i replaced the coolant temp sensor and am still getting the code. im gonna replace the thermostat housing and walnut blast the intake valves.. Should i replace anything else while i am at it? Water Pump? I plan on also doing spark plugs? any suggestion on the plugs would be appreciated as well. I dont use mini coolant, should I?

 

P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

If you haven't already, Thermostat is a good place to start. We have some great Water Pump Super Kits here if you want to replace the water pump at the same time as the thermostat. The water pump in the kit is the OEM supplier one and the thermostat is Genuine MINI. The kits also include a lot of hoses to replace in the cooling system and the correct MINI coolant. Yes, you should use MINI coolant 82-14-0-031-133. It's a good kit to help save you money if you want to go ahead and do some preventative maintenance while you're in there to replace the thermostat. For spark plugs, use OEM supplier or Genuine 12-12-0-035-531 here. Let me know if you have any questions.