LOUD at mid-RPMs

[TSIanger]

Ok I have 91 TSi FWD, its old, been through some hell and has 170k miles. It also has all the typical dsm problems (idle surge, cracked exhaust mani, blah blah) I have a boost contoller and its set very low, so I dont know what the problem is. Once I get about 4500 RPM my engine gets insanely loud, I drive this car like its some rare exotic, so it hasnt been abused. Also it has a rebuilt head. WHAT THE HECK IS THE PROBLEM? Any ideas?

 

[1G_laser91]

check the exhaust hose at the bottom..

 

[TSIanger]

The cam-timing shouldn't be off, being as it just had a pretty significant top-end overhaul. How do I go about checking my timing anyways? Thanks for the insight

 

[805eclipse]

my car has the same problem once i hit about 5000 rpm my car gets crazy loud and it even is to loud below that rpm. it also shakes a hell of alot at idle.. and i also just had my head replaced.. i took it to RRE and they said its has something to do with the balance shaft belt being off so check that.

 

[Defiant]

Check balance shaft timing and motor mounts.

My money's on your rear balance shaft being 180° out. I just got back from that. Thank you, Mitsubishi dealer

 

[LiquidOC]

How would I go about checking my balance shaft timing....i seem to be having the same noise problem along with fuel cut around 4100 RPM's.