2000 v6 auto 66k miles. This just started happening that when i start my car cold I have no oil pressure, then after a few mins of driving it all the sudden flicks on to normal oil pressure.... what gives? Could an oil pressure sending unit just flick on like that? and once it initially flicks on, it never flicks back off. Its only on cold starts. I have oil.... confused. Also if this sounds like the oil press. sending unit- where is this located? thanks!