Coolant Temp Overheating

[X5SHARMA]

Hello All,

So for starters I definitely missed out on the Midnight run a little while back but now I've moved from queens to jersey which gives me space to actually work on my car now rather than doing everything on the street.

So here is my dilemma:

Yesterday I was driving back from work which is approximately 25 miles. Somewhere in between I get a check coolant sign while I'm driving approximately 45-50 mph. Immediately after that maybe 2 minutes later I get check coolant temperature sign. Now the car starts overheating so I pull over immediately at the first chance.

The last thing I changed on this was the lower rad hose from engine to the radiator. Now I remember how hard it was getting that hose off and then getting the new one to get in there. Anyhow that hose came off from the radiator and had spewed all the coolant out. I was able to hammer it lightly and get it to be in there again and re-filled the coolant that I picked up from a Sears nearby. (Originally when i had flushed and re-did this job I have only used the BMW coolant but I had no choice and bought the prestone and put that in). Turn the car back on all seems normal the temp gauge is right in the middle and so I start driving immediately it shoots to the red area and I pull over again. So luckily I was only a few miles from home and crawled home letting it cool every 1/2 mile - mile before it shoots to red. Now I re-checked that hose and its still connected and no coolant dripping after I re-filled it. Also at this point now before I get home I also have the SERVICE ENGINE SOON light on which im guessing might be from turning it on and off or probably a sensor.

I am wondering if the sensor that is attached in that hose that I also replaced is the culprit. I wonder if it fried when it detached itself and started overheating.

I do not have warranty so I'm on my own on this. My first guess is to change that sensor or perhaps the sensor and the entire hose itself.

Please give me suggestions as to what I should do. Again the car keeps overheating but I do not see any coolant loss.

Recent changes:
New Expansion Tank with thermostat
New hoses all of them

In my recent post i posted pics of all the changes