Noises problem
1997 Buick Lesabre 6 cyl Front Wheel Drive Automatic 47.000 miles

Hi .My car makes very laud noises and i thought i have problem with transmission.After checking out transmission i was tald it has vacuum leak.while car is running if i pull out oil check stick out noise will stop an seems like air goes in to the engine.how i find out where is the problem.Any help appreciate.thank you

it was pcv valve.pcv valve was missing rubber around it .that was the reason check engine was showing egr valve ,missfiring and air leak,+very loud noise.hope this help someone in future