Hi All, Iâ??m having a few problems with the car, after having a few bits done from the garage. Firstly the car itâ??s not idling right, it drops to about 500rpm and stay there for a long time. Even after driving for some time it donâ??t go back up to normal. Next the engine coolant temp goes up and down like a yoyo, especially when driving, at one point it almost over heated, but other times the needle goes just below the red line and jumps back to normal. The car had new valve stem seals, new 1.2mm head gasket, head skimmed, port and polish head, new oil and fil