Blow off noise..

[MelbStazz]

after fitting the new radiator and finding that the car was running rough i thought that a run around the block might fix the rough idle ( caused by dirty fuel sitting there). Half way around my little circuit i decided to open the car up. It started to cough and splutter and then all of a sudden came on boost and rocked :D , changed gears and got the whooosh noise of a blow off. Now i know my car doesn't have one bar the factory one.
Could it be something to do with the radiator/cooling system working properly?? or is it more a manifold leak? this has me puzzled as the noise wasn't there when the old ratted radiator was in there.. i reakon i was lucky not to cook the turbo or the head!!!!
any help would be appreciated
drew :D

[ProZac]

Starions do not have a factory BOV. What you may have heard was a flutter in the turbo due to the compressed air in the intake pipe pushing back on it.

[MelbStazz]

could that noise be exaggerated by the induction pipe not being 100% sealed?
im getting a new pipe made up all polished and schmicko, maybe i should be a BOV plumbed in as well?
:beer

[Camotec]

Check all your hose clamps on the intake piping after the turbo as, I had a bad clamp which wasn't tightening properly and when i gave it boost the seal would be lost giving quite a large PPSSSHHHT! noise.

Anyways my 2 cents

Cheers

[SpidersWeb]

Ive found the more you open up the intake, the louder turbo noises get.

By simply cutting my air can, my old turbo's turbo-whine almost doubled in volume.

Id say you are getting compressor surge which sounds similar to a BOV except its more of a fast flutter than a loud PSSST. Id agree with above and say you have quite a large leak somewhere. It will be on the compressor side.

[SIRIUS]

yeh when i first fitted my cooler i hadnt had time to fit the BOV....got a very nice turb flutter...lol sounded like a hks sequential...lol...but its not to good for the compressor...

[evogalant]

Yeah mine has pretty loud turbo spool up noise now that it got the wastgate fixed and the turbo kicks in right on 2000rpm (silly tdo4). Im also running a pod filter so that would be making a bit of induction noise.
Makes alot more noise and bov goes of alot more now.

The noise your probably hearing if you don't have a bov is what prozac said, the air reversing in you intake pipe and going back against the turbo compressor wheel.
My car does it very loudly if i dissconect and clamp the vac hose to my bov. Also test drove a vr4 cordia that had a tdo4 and small intercooler piping but no bov and this also did it rather noticibly.

[MelbStazz]

well the culprit was the induction pipe :D clearly broken all the way through! there was the noise and leak. it still puzzles me that this noise only appeared after the cooling system had been replaced. i have wrapped the intake piping with thermal wrap for the time being, i will be making the new induction pipe a priority. I have just started my 2 weeks holidays to get some work done on the car.
keep you posted on the new induction piping. I'm guessing that it's kinda going to look like a intercooler pipe, without the cooler ( for the time being ).
thanks for all your help everyone...
:beer

[Chris 83JA]

It could be that the intercooler just amplified the sound, and that the problem has been there for a while

[MelbStazz]

the car is without a cooler, im in the process of saving up for a cooler, the car's off to the exhaust place to get the induction tube made up. I'll post some pics when its done if n e 1's interested...

[Camotec]

Sounds good, yeah post pics :)

Cheers