There are two pipe plugs in the block that will drain it completely if removed, one on each side. Then you only have to flush the heater core by removing the hoses and connecting garden hose or jug of distilled water. Remove lower rad hose to drain radiator completely.

 

I installed the kit and it's super easy to do; I do have a question though. I put the 170 system in but watched my Temps hit 190-198 today on a 74 degree day then get back down to 168-174. Did I possibly not bleed the system correctly or could I have other issues such as the fan clutch going out?

 

Its possible it is not bled correctly (I assume you followed the instructions here: https://store-9jc1bjf1r3.mybigcommer...thermostat.pdf ) Have you driven it on the highway yet? Did it get hot idling or on the highway? Best test is to remove the thermostat element completely and see what it does. Hot idling is bad fan clutch, hot on the highway is bad radiator.

 

I ran it 30 minutes away at 70 mph and it stayed at 171-178. It only jumps up at red lights then goes back down.

 

Bad fan clutch

 

Hey @Extinct July is my maintenance cycle date to change the coolant and thought I might do this mod (finally) while the system is drained. The gray OEM thermostat is about 50K miles old at this point anyway, and works great, but a preventative replacement is probably due. Question - I read this entire thread - how is the latest batch of castings? I saw some a year-ish ago had issues with pinholes?

Also, any official torque specs for the fasteners? Both the bolts and the port plug.

 

All the castings are now coming out of a brand new mold and we haven't had any pinhole issues. As part of that revised manufacturing procedure they also put sealant on the pipe plug from the factory so there's no longer a need to remove that and put sealant on it. Torque specs are in the instructions that will be a link to in your order confirmation email.
Let me know if you have any other questions.

 

Does anyone else get a low engine temp code? I swapped a 180 thermostat in and very occasionally get a the error code. Regardless of the outside temp, in the winter it was maybe slightly more prevalent 3x a month. I am wondering if the CTS, coolant temp sensor is the issue, any way to test that, or just put a new one in?

 

I was tired of getting that code so I simply swapped to a 190° stat back in fall. I will see how it goes as we start to get into warmer temps here in Northern Colorado, but my plan is to stick with it for now. So nice not seeing that code every few days.

 

@redrover75 My 04 only throws a code if the engine stays sub 165, but I did add a grill cover for winter