Coming from a stop, and as the car started to accelerate, I heard a quick and brief sound coming from engine , it sounded almost like engine "dieseling", then I started to feel the car is not responding well to the gas paddle(it continue to accelerate but very slowly), car speed reduced to about 30-40 mph with a full throttle, all gauges are good, no engine check light. Within about 4 miles, the car traveling speed came to less than 10 mph, and I started to smell burning oil. When I opened the hood, I can some oil leaks coming from the head gasket cover dripping on the manifold. However, the engine sounds normal and smooth at idle (around 900 rpm), Temp gauge is normal. Also Gear shifter is locked, and still no engine check light.

Any suggestion is appreciated.

Thanks

 

welcome to the forum Possible cat clogged up.