weird 'grrrrrrr' noise under load?

[jt15833]

this has been an issue for a very long time but never this serious since I just finished my head gasket. I beleive it started when I started changing out exhaust components (turbo back only). first i added o2 housing and dp, then catback, then test pipe. each different component changed the occurence of the noise which makes me think this is exhaust related, but let me try to describe it.

the noise itself sounds like what you would hear inside a very fast car, i mean 1000hp or something. i'll be driving normal, semi loud exhaust (3") sound but then at certain intervals (next paragraph) this noise occurs thats just like GRRRRRRRR really loud inside the car. I don't think its too loud from the outside tho. also I can feel some more vibration it seems through the gas peddle.

now for the times of occurence. it's not boost related, but seems more load related. in first gear i barely have to try to get moving and it will make this noise from 1000 rpm up. Second gear will be often occurences between 1000-2000 rpm then be full on from 2000 rpm up.Third is pretty choppy, but definetly still there until 2500, then it's full on all the way up.Fourth is choppy til 3k, then full on.Fifth hasnt been tested but most likely the same. I can be at 0inhg/psi and it will still make this noise.

please someone tell me theyve heard something like this its driving me crazy! my car has no decent exhaust note when your inside the car since if you ever try to get on it this GRRRRRRRRRRRRRRRRRRRRRRRR noise reverberates through the cabin.

[ca18detgabby]

sounds like exhaust rattle........

[Ca18det240sxchk]

something is loose... I had the same problem and it was my turbo manifold slowly seperating from the turbo itself...

[jt15833]

its not a rattle noise i dont think but possibly exhaust leak? when I took off the exhaust mani to do headgasket the turbo was loose from exhaust manifold, all 4 nuts. I tightened those and thought i'd get rid of problem but now its worse than ever lol. specs aremegan o2 housing (not divorced)rsr downpipetest pipeblitz realize tt exhaust

[nismoplsr]

Yea sounds like a rattle to me tooo. Perhaps something isnt mounted right or you engine mounts are shot or missing hangers or something.