estomax

iTrader: (2)

hey guys,

i am pretty sure i didn't use to be able to hear my ct15b so much, especially even around 5-10 inches of vacuum lately as i am accelerating. There is a loud whooshing noise from the turbo as the noise pitch goes along with the turbo spooling up/down. i dont remember my big turbo 240sx having this much intake noise (but then again i had a loud exhaust then, and i'm rocking the stock sc400 exhaust right now).

today i took my intake off today and the compressor wheel looks okay, no in/out shaft play and barely perceptible side to side shaft play.



mye fondling the compressor wheel here:

others here with a ct15b / 1JZvvti, how loud is your turbo? i'm wondering if i am worrying for no reason but neither my wife or i remember hearing the turbo so loudly before..

my second thought is a boost leak but that would have to be a pretty big boost leak and i would think the car would run super rich and not cruise normally. but drivability wise it seems fine.

cheers
Marko

blk&blu*j

iTrader: (1)

Those turbos are known to crack at the rear housing.

ArkLaTexSC

Lots of noise generally indicates something near the turbo is open to outside air. Check your couplers, piping, housing.

Really the easiest thing would be to run a smoke test. Though my money is on the housing failing, it's worth to smoke it first.

estomax

iTrader: (2)

i'm going to take the rear housing off to have a peak at the ceramic turbine wheel. i'll also do a boost leak test from the first pressurized coupler out of the turbo onwards..

thanks for the responses! i'll keep you posted. if nothing wierd shows up i will drive it until something breaks

cheers
Marko

blk&blu*j

iTrader: (1)

The actual rear housing can and does crack on those turbos.

estomax

iTrader: (2)

Thanks blk&blu for clarifying that. i checked the turbine and there are no cracks. also stuck a usb camera down the o2 sensor hole and the turbine looks good. i am hoping to find a leak in the couplers somewhere, besides that i have no explanation. will test that next.




a little clip of the camera for ****s and giggles

estomax

iTrader: (2)

well i feel dumb now (right after hooking my air compressor up past the turbo and finding this in a matter of seconds). The lesson to take away is : The 1JZ VVTI motors run GREAT even with a massive hole on the side of the throttle body.

i really didn't think i had a boost leak because it idled and ran fine at low throttles, but my traction control delete had undone itself on one side apparently. Luckily whatever i had bolted on the outside fell out and did not get sucked into the motor. for the record, that 1 cm hole was good for -2psi peak boost that i noticed that i was missing. (13 instead of 15 psi)



Marko

estomax

iTrader: (2)

fixed it by drilling my jb welded other side and this side with a 17/64 (or 9/16 if u cant find that) and tapping a 3/8" NPT and putting a plug on both sides. properly fixed for good now!

Ali SC3

iTrader: (10)

nice find, don't forget to use the liquid sealant stuff on the threads it also helps hold it in place also.