Hello everyone. I have a 87 TII with 155.00 (don't know about the motor mileage) . I make the car rev to about 7500 and let off. When retuning to normal driving a hear a loud exhaust noise coming from the turbo area. After about 2 to 3 min of normal driving, it goes away.The car is warm when this happens.I think its the BOV but it still runs pretty good with the noise, but I never get on it with this loud noise present. I do have RB exhaust with some kind of after-market mid pipe.(came with the car). Any help will be welcomed.

 

Loose downpipe?