when starting the car from cold in the morning i get a knock/rattle noise inside the car but nothing can be heard outside. i jacked the left side of the car up once before starting it and there was no noise at all but jacking the front up made the noise worse to a point where it could even be heard outside (but i still cannot trace it).

i have checked all the heat sheilds, exhaust mounts etc. Could it be a engine mount? it only happen when the car is cold and there is no strange vibrations or anything it drives perfectly.

any ideas thanks