I have an 03 Range Rover and I’ve replaced the upper coolant hose and expansion tank. But suddenly the Check Coolant Light came on. I’ve checked under the hood and the sensor looks fine it’s on the top mark bobbing in the fluid. Would this be from the cheap expansion tank I bought or would I have a leak in the system that I don’t see? Thanks. This car has also left me stranded from the OEM expansion tank blowing up on me on the highway.