HELP: Water Temperature too Low after CSF Radiator Upgrade and Aux Radiator Upgrade

[zcchen]

Hi,

I drive a 1M. Recently, I upgraded my AUX radiator to a custom one roughly the size of a 32-row cooler. I also installed the CSF performance radiator. On the oil side I have a Setrab 32 row installed in the stock location replacing the stock one. After these installs, my water temp in everyday driving has been steady at 80-85C and oil temp at ~100C while the ambient temp is ~ 32C. With this exact same set up, I ran a track day. Although I forgot to data log, I remember seeing water temp at ~110C and Oil temp at ~135C after a few laps. Hence, it is not like my cooling system has over-capacity. For everyday driving I want to target water temp to be 90C.

So here is my question, or rather questions.
- Is it bad to run the car in everyday driving with water temp being at 80C, oil temp at 100C?
- If so, I want to fix it. What is potentially wrong? or do I simply to have too much heat exchanger capacity? or maybe I messed up the thermostat during install? or something else? How can I best diagnose? Where do I start to look?
- If not, then I will leave it as is.

 

[JBacon335]

I wouldn't be too concerned as the oil is getting hot enough to boil out any moisture, and that's really the biggest issue

 

[Asbjorn]

According to MHD the ambient threshold for coolant mode = "high + kft" (thermostat forced open) is 37C, which means the DME will target 80-85c if ambient is above 37C. The weather may only be 32C according to the weather app, but check the cluster temperature which is measured by the car just above the road surface. It may very well be above 37C, even if the weather app says 32C here. And then the car enters that mode. Another explanation could be if you selected track or sport cooling modes in MHD (which you never want to do, unless you are drag racing). Finally I assume your stock oil thermostat is still in place, so you dont need to worry about oil going too cool. There is basically no reason to run oil thermostat delete except in very special cases.

Anyhow, during normal street driving it would hit 80-85C when in high+kft mode no matter the size of the radiators. It does this by adjusting the speed of the electric water pump and fan. It is only when the requsted power exceeds the capabilities of the cooling system, that you see overheating. This is normally not possible on the street.

Also it is not possible for the car to run too cold. Because it would just turn off the water pump and fan to heat up if needed.