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Whistling noise at idle, builds with throttle

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Whistling noise at idle, builds with throttle

Postby blairtron » Sat Sep 22, 2018 2:24 pm

Hi guys,

Today my Bighorn started whistling, it's noticeable at idle and gets higher pitched with a bit of throttle application. At higher rpm (say >1500) I can't tell if the noise is still there or not because the exhaust drowns it out (this might be a good thing :lol: ), the boost gauge used to jump to ~11psi pretty quickly under power but now it only seems to go to 8-10 after sticking the boot in for a few seconds. Performance seems okay still - certainly a lot better than last weekend when the vac line from intercooler->boost gauge T->fuel pump broke in half and the bastard didn't want to accelerate much past 80ks in 5th - but the apparent drop in boost has me concerned.

Is the turbo on the way out? I've thought about upgrading the turbo before but it was never a properly serious idea, if it's going to need replacing anyway then that's something I'll actually look into because a bit more power and torque wouldn't go amiss!
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Re: Whistling noise at idle, builds with throttle

Postby geeves » Sat Sep 22, 2018 3:16 pm

stethoscope or long screwdriver might help locate the noise. My money is on an air leak somewhere and they can be harder to track down than fix
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: Whistling noise at idle, builds with throttle

Postby blairtron » Sat Sep 22, 2018 3:28 pm

An air leak would certainly be the lesser of two evils, the bit of hose I used to replace the section that broke was kindly donated by the EGR removal so probably wasn't in great condition to begin with. That's literally the only thing that's changed between things being fine and things being... not fine, so I'll replace that line again and see if there's any improvement
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Re: Whistling noise at idle, builds with throttle

Postby blairtron » Sun Sep 23, 2018 11:12 am

Replaced the replacement vac line and no dice - coincidentally or not the problem got worse, now there's no boost until ~1800rpm at which point 5psi dumps in and 8-10psi around 2400. Driveability is shite :lol:

Pulled the intercooler and intake piping pre-intake manifold off (thus manifold was intake air's point of entry, and turbo was spinning but not feeding air into engine) and it still whistled like a referee :x Pretty positive it's the turbo at this point unless anyone can think of something else... this is looking like an expensive fix
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Re: Whistling noise at idle, builds with throttle

Postby 4wdWiz » Wed Oct 03, 2018 10:52 am

I had low power when there was a leak between the exhaust manifold and the block, there's a metal shim/gasket in between that vibrated and made a whisteling noise. Tightening up the bolts fixed it.
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Re: Whistling noise at idle, builds with throttle

Postby ElIsuzu » Fri Mar 22, 2019 1:49 pm

Did you figure out what the problem was mate?
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