Turbo internal wastegate q's

[thegreatestben]

Today I tracked down my mysterious noise which was a tick tick tick particularly noticable as I went down alleyways and past traffic barriers.
Spent ages looking for it, couldn't find it. Noise seemed to be getting worse/embarassing so I had another look today and found that the noise was caused by the wastegate flap.

At idle with the actuator on it makes the noise, a tick tick tick.
If I take the actuator off the noise gets quieter but somewhat still there.
If I open the flapper by hand the noise disappears.

Is the flapper suppose to close HARD against the turbine housing? Because the harder I apply pressure the more noticable my tick tick tick becomes.

I haven't played with a turbo like this before, so wasnt sure if the actuator is supposed to be holding the flapper hard up against the housing (this is how I've had it)

Or is it supposed to be sort of just in the right position for the flap to be just against?

What would you knowledgable bunch recommend I do to remedy this noise?

It's a TD05H twinscroll off've an Evo IV if that helps in any way

[thegreatestben]

Video:

[Akane]

the flapper is suppose to be FIRM against the housing when you're not boosting / idle / have not reached the desired boost.

I'm going to jump to the conclusion that you have a leak somewhere, and closing the flapper is forcing the exhaust gas to this leak and making it sound like a tractor, and opening the flapper is letting most of the exhaust gas routed via the wastegate hence the less ticking noise.

Just a thought, that's what I'd check first.

Edit: It could be that the manifold is leaking, opening the flap reduces the pressure in the manifold (exhaust gas does not need to go through the turbine wheel), hence the noise is gone. But if you close the flapper, the exhaust gas is "build up" in the manifold and it's finding a way to leak around the manifold.

Just another thought.

[thegreatestben]

seems more like the noise is actually coming from the wastegate flapper.
Thats why it was so hard to find because it's inside the exhaust housing/downpipe. As hard as I apply force to seal the wastegate, it won't stop making the noise, it does however vary in sound depending how much pressure is applied.

Why would the flap no longer seal?

[steve murch]

the twin scroll hsg also brake the dividers in the scroll
the wastegate flaps are well know for eating out the seat the flap wont seal correctly

[thegreatestben]

So what would be your recommendation to fix?
Have access to engineer father

[steve murch]

another hsg

[mjrstar]

I have heard of the 'v' band clamps losing their grip or not being done up correctly. This may allow exhaust gas to escape between the housing and the core.

My evo 4 turbo has a small amout of leakage passed the flapper at idle, even though the flapper appears to be firmly held against the opening.

mine also tas a tick from the exhaust at idle which i cannot pinpoint, althought i am planning on ignoring this until mid jan when i'll fit up my modified evo 9 turbo.

[thegreatestben]

Cool, so I had a closer look at the wastegate actuator and the bit on the end with the hole that goes over the flapper arm was *just* touching the housing so I added some length into the actuator arm to bring the arm out.

Noise went away upon start up but came back when I came back outside, but it's ALOT quieter. Not free boostin any more either. Lols

How much is a td05 off've an Evo IV worth?
There's a nice titanium core one off've a later evo for $550 on trademe that has caught my eye

[steve murch]

Cool, so I had a closer look at the wastegate actuator and the bit on the end with the hole that goes over the flapper arm was *just* touching the housing so I added some length into the actuator arm to bring the arm out.

Noise went away upon start up but came back when I came back outside, but it's ALOT quieter. Not free boostin any more either. Lols

How much is a td05 off've an Evo IV worth?
There's a nice titanium core one off've a later evo for $550 on trademe that has caught my eye

dont touch it they fail very easily,they suffer the same faults as ceramic

[thegreatestben]

Well the noise is better but it's still present and it really lets the rest of the car down What model evo has the turbo to have then?

Or could/should I look at switching to an external wastegate.
I'll be chasing a few more kw anything over 200 and I'll be happy

[steve murch]

don't go for any titanium/magnesium turbo, the 7 upwards can push you to over 250kw with the right tune