Turbo going bad?

[Zeph240sx]

Hi guys i have a 180sx i just bought few months ago. Lately i notice my turbo is making sounds like a tractor motor. It can still make full boost 10psi* at 3000-4000rpm dies around 6000.
Is the sound normal? or is my turbo is starting to go bad? This is a T25G

Thanks

[blkvrtswp]

I would first check the turbo to manifold and turbo to O2 elbow gaskets. When those leak they can make all kinds of loud noises. Stock turbo or what brand? Also pull the inlet piping off and try to move the turbo shaft up and down, in and out. More than 2-3 millimeters play is not good on a non-ball bearing turbo.

[Lobo240sx]

^^^ This and one or more of the 4 nuts could have backed out on the Turbo to Manifold. Usually when that happens, your gasket gets chewed up from the exhaust heat. Check all your gaskets and nuts including the turbo manifold to engine.

When at idle or after hitting high boost, where is your vac at on idle?? Should be at -20 . If it's lower, usually that means there's a leak somewhere. If your intake doesn't have a bunch of oil inside it, the turbo should be fine.