What is this weird chirping sound?

[RubyRed15]

Nobody seems to know what this is. My tuner has been able to dial the noise out by lowering the boost, but this has cost me considerable power. The noise occurs around the boost peak, and actually goes crazy if the boost gets a little too high (second sound clip). Theories include:

1. Turbo bearing problem
2. Leaking DV+
3. Boost leak other than DV+
4. "Open throttle compressor surge" aka "full throttle flutter"

Mod list:

• DV+
• Airaid tube/panel filter
• ATM IC/charge pipes
• UPR DVCC
• Catted 3" TB exhaust
• Vargas (Borg-Warner EFR) upgraded WGA

Sponsored

 

[Cardude99]

It doing it just before your let off/ gear change. Could be a leak

 

[RubyRed15]

It doing it just before your let off/ gear change. Could be a leak

No, it's actually happening at or near the turbo spooling to peak boost.

 

[TorqueMan]

No, it's actually happening at or near the turbo spooling to peak boost.

Can you associate it with any particular RPM?

 

[RubyRed15]

Can you associate it with any particular RPM?

If I floor it at 2500, it would reach peak boost and chirp around 3200.

 

[Brian V]

Tensioner if you're lucky !

 

[RubyRed15]

Tensioner if you're lucky !

How would I test that?

 

[Brian V]

While you can have someone raise the rpm's while you observe your engine bay . Specifically the front of the engine . Hopefully it is not the timing chain tensioner .

 

[RubyRed15]

While you can have someone raise the rpm's while you observe your engine bay . Specifically the front of the engine . Hopefully it is not the timing chain tensioner .

I'm going to say this is not the problem. I've done that, and there is no noise from the tensioner (at least not under free revs).

 

[Brian V]

I'm going to say this is not the problem. I've done that, and there is no noise from the tensioner (at least not under free revs).

only under load than . That changes the equation . Do some more pulls to narrow it down to a more specific part or area of the vehicle .

 

[TorqueMan]

If I floor it at 2500, it would reach peak boost and chirp around 3200.

What if you floor it at 3000 and it reaches peak boost at 4000 (or whenever)? I guess what I'm trying to ask is does the noise always occur at the same RPM? What happens if you close the throttle immediately after hearing the first chirp?

 

[RubyRed15]

What if you floor it at 3000 and it reaches peak boost at 4000 (or whenever)? I guess what I'm trying to ask is does the noise always occur at the same RPM? What happens if you close the throttle immediately after hearing the first chirp?

At some point across the rpm band, the peak boost will fall to a level that there will be no chirp, but I dont know where the point is, exactly.

Let-off behavior varies. If it's a single chirp, nothing happens when letting off, but I have heard "turbo flutter" when letting off after a "multi chirp" a couple of times.

 

[Brian V]

At some point across the rpm band, the peak boost will fall to a level that there will be no chirp, but I dont know where the point is, exactly.

Let-off behavior varies. If it's a single chirp, nothing happens when letting off, but I have heard "turbo flutter" when letting off after a "multi chirp" a couple of times.

What is the WGA vacuum set at ? Your symptoms lead to the WGA .

 

[RubyRed15]

What is the WGA vacuum set at ? Your symptoms lead to the WGA .

I'm not sure how to answer that. I get ~-8.8psi on the boost gauge at idle.

 

[Brian V]

I'm not sure how to answer that. I get ~-8.8psi on the boost gauge at idle.

You are using an after market wga so you need to know the preload of the spring for vacuum .. you need to do some researh on the subject now .

Sponsored