HELLO i'm from Romania a i purchased a Mazda CX-7 from US, has 20,000 miles and at start is making a suspicious noise as would not be oil or pressure in the ramp, noise disappears in 2 sec with witness extinguish oil the board, if the engine stops and we start immediately there is no suspicious ,everything is perfect , friends told me that the filter doesn't keep the pressure in the engine bay when the engine is stopped.any idea of this problem?

 

VVT system makes some noise on start up. Normal

A lot of noise though means you need to have it checked as there is a TSB on the VVT system on some cars.