Turbo Howling..?

[Ultimategtr]

hey all.

happened yesterday and today.. theres something howling when driving for the first 2-3 mins.

i normally warm my car up for about 2-4 mins.. the oil pressure drops from about 7bar to 4 bar and th revs dropped a bit.. like normal.. and i drove off.. careful not the get the boost gauge newhere close to 0.. shift at 1500 or so..

yesterday it howled abit more.. cos i didnt let it warm up.. only like 2 min warmup. this morning was kinda intermittant cos i let it warm up for jst about 4 min.

im sure its not a leak as we tightened the fmic piping up properly.. i double checked it when i got home on the day of the install.

it boosts fine tho.. no lag etc.. only happens when the cars coldish..

any input on what the noise could be?? kinda has me worried as the cars only done 85xxx k's and im the first owner.

My mods:

Full exh

6*3*80 HDi FMIC

Apexi Powerflow

Factory boost solenoid (low - 7, high - 12-14psi) NOTE: i HARDLY use high boost, if i do its only for a few seconds then flick it back to low.

i hardly boost my car. no really.. i hope its not my turbo but something tells me it is.

[Ultimategtr]

NOTE: it is also getting very cold here in auckland. im talking below 10degrees cel. it must hav been about 2-5 degrees yesterday and this morning..

my mate thinks its the vortex thing happening with my powerflow filter? going to check for shaft play after work today. fingers crossed!!!

[R31Nismoid]

Howling probably isnt the best description... hmm..

Does it do it on idle if you rev it?

Or only under load?

Where is the noise coming from, right/left side of the enginebay?

Anything you might be able to provide will make it easier.

It sounds like a leaky cooler pipe to me, but everyone describes noises differently

[Kinks]

I've heard many RB25's make a howling sort of noise.. not sure what it is just the resonances in the intake setup. Mine makes a noise but I'm not fussed unless it also starts blowing smoke

[Craved]

i vote for exhaust gasket leak, without knowing the definition of "howling".

common issue with the lock tabs not working or breaking on the turbo flange bolts. But some answers to R31Nismoid's question will help the diagnoses.

[Ultimategtr]

cheers so far guys.

it only happens when i drive it in the cold.. its been around 2-5 degrees here lately so blooody cold.. thats it.. only for a few mins.. i checked all the fmic piping again last night.. all tight..

i doubt its the exh mani tho cos i never touched it..

i checked the turbo wheels for shaft play and it seemed sweet.. no play at all.. to be oversensitive, id say the bearings were a weee bit noisy but thats it.. i cud hear it when i spun the wheels with my fingers.. it boosts fine.

[Lachlan33]

You say its only hapening with the colder air? Maybe like what was sugested your getting a sort of resonating sound that is maybe only occuring with the colder, denser air?

Can't say as ive ever heard a 'howling' from my turbo. Just how loud is it?

[Green_s13]

to me it sounds like a turbo gasket leak

[bubba]

+3 to turbo gasket leak.. after putting my big front pipe on and having to perform some percussive maintenance on the dump pipe bolts.. take car for drive at over 5000rpm it sounded like there was a banshee under my bonnet. Tightened all turbo>manifold bolts and the banshee died

[Ultimategtr]

this noise only happens unde very light throttle.. ie shifting at like 2500rpm or so..