I am uncertain about my thoughts and do not have a clear perspective.Is there a problem with the head gasket?

[Patagil]

Approximately four months ago, I purchased a 2011 Cooper S 1.6T with 184 brake horsepower. As is my customary practice whenever I acquire a new vehicle, I promptly performed a comprehensive service, including an oil change, replacement of air and oil filters, and replenishment of coolant, among other necessary tasks.
Everything was going well until last week when I went to inspect something in the engine compartment with a buddy and saw that the coolant levels were far below the minimum level. I refilled it once again, and everything seemed to be in order until I conducted a head gasket test as a precautionary measure to ensure that everything was functioning properly.

The liquid in this RELD cylinder head gasket kit undergoes a rapid colour change from blue to green within a few seconds.
Upon realising the situation, I felt a sense of urgency to replace the head gasket.
After taking a moment to relax, I got into my vehicle and connected my OBD2 reader to monitor the temperatures as I went on a one-hour drive at high speeds on the highway.While on the way back, our vehicle encountered heavy traffic, prompting me to test its susceptibility to overheating. Witness the absence of anything! The temperature consistently remained within the range of 90 to 102 degrees Celsius.
The next morning, I conducted the head gasket test once again, and once again, the liquid turned green within seconds.
I am uncertain about my thoughts.
Am I facing an issue or not?

Apologies for the lengthy narrative, but I aimed to provide you with a comprehensive level of information.

[Istairde]

Are you using the appropriate test fluid for petrol?

[Patagil]

I am now using a universal kit that I have obtained from the online marketplace Amazon. The specific product may be found at the following URL: https://www.amazon.co.uk/gp/aw/d/B07RS3N98V?psc=1&ref=ppx_pop_mob_b_asin_image
I have also conducted a test on a Jaguar XE 2.0-liter petrol vehicle, and it performed well.

[Istairde]

These engines operate at temperatures ranging from 105°C to 112°C, which is considered quite hot. If there were any issues with the gasket, it would quickly become apparent as the engine would expel coolant from the header tank.

[Patagil]

However, I do not exhibit any of the symptoms.
The quality of the oil is satisfactory.
Coolant: It is in satisfactory condition after being refilled.
There is no presence of smoky exhaust.
Malfunction: absent

The automobile operates in the usual manner.

That is the aspect that is causing me extreme frustration.

[Istairde]

Perhaps the automobile is just functioning as intended, but your driving is causing frustration.

[Grundysp]

If your engine is not experiencing misfiring or overheating, it is likely that you have a coolant leak. Over time, some coolant pipes may become fragile and develop cracks, leading to potential leaks. There is a possibility that the water pump is also experiencing a leakage.

If coolant is entering the engine, it would result in the presence of a mixture like a milkshake in either the oil or the coolant reservoir. If the coolant were being consumed in the combustion chamber, there would be a noticeable emission of white smoke out the tailpipe after the exhaust system had reached a high temperature, like the output of a smoke machine.

[MutanX]

I would do a pressure test to see whether it is able to withstand the pressure.

Another possible cause I have seen is a malfunctioning reservoir cover or a fracture in the threaded section of the reservoir. It is advisable to inspect these components as potential sources of coolant leakage.

[Patagil]

Thank you. I will examine it.