My car has just been tuned but, with the heavy rains that have taken place recently, it started failing. The oil sensor turned on and the vehicle started to lose power. When this happened, I let the car cool down and the levels were alright, so I drove back home but, when I was just about to arrive, the tappets made a terrible sound and I have not moved the car since then. What should I do? Is it the oil pressure sensor? Or the pump? Or what else can it be?