300zx tt rattling noise

[Azazel703]

My 1990 300zx tt has a rattle noise coming from the driver side back of the engine I checked the turbo and the intake side has no play. The noise only happens at idle and goes away after 1500 rpm a

[Ace2cool]

Is it possibly exhaust noise? Sometimes the heat shield bolts on the manifold work loose and can cause a rattle.

[amc49]

Check your mounts, that can be an indicator of bad ones. The harmonic has more power down low as it then has time to shake the object in between power pulses. Harmonics being time based things often.

[DCaff300ZX]

Dust shields for the brakes, exhaust shields as mentioned if the car has been off-road, they get mangled and my NA rattled bad until the OEM exhaust was replaced. If no go there then maybe look deeper as amc40 suggests, looking at mounts and e-brake linkage, etc.

[Azazel703]

The noise also goes away when I undo the exhaust from the down pipe

[DCaff300ZX]

Then it sounds like you have an issue with the heat shielding contacting the pipe inside, the same issue I had with my NA from a sudden offroad trip. The shielding gets crinkled and bent around, no way to really fix it other than replacing your exhaust with non-shielded ss or aluminized piping.

[Azazel703]

Ok thanks for all the help