I could do that, but there is something wrong. I would like to know what is wrong and fix it without potentially doing further damage to the car or turbo.

Mine seems to leak a little where the wastegate flapper rod goes into the exhaust housing. I'm not sure how to fix it, but it doesn't seem to affect anything. I think that is where my high boost whistle comes from.

I figure that the turbo spins freely and for a long while after I turn the car off. If the bearings were going out I would expect it to stop spinning rather quickly.

djp0623, your post got me thinking about the wastegate. With the actuator arm attached, I cannot make the internal wastegate open by hand. If I disconnect the arm, the wastegate moves freely. If I pull on the actuator arm, it barely moves at all, maybe 1/8 inch.

Should I be able to move the arm by hand? Is there adjustment I could make?

These are just some various pictures from the last month or so.
https://www.miataturbo.net/attachmen...ine=1349019213
https://www.miataturbo.net/attachmen...ine=1349019213
https://www.miataturbo.net/attachmen...ine=1349019213
https://www.miataturbo.net/attachmen...ine=1349019213

Mine has a little leak from here.

https://www.miataturbo.net/attachmen...ine=1349019961

I had to tighten my wastegate are to where I can barely get it to move by hand. It seemed tight at first, but I was unable to hold target. After tightening it down it held target.

I thought I fixed it for a while today. I watched and I adjusted the actuator arm following his instructions:
1. Remove C clip on the waste gate arm
2. Undo the nut that holds the rod extender.
3. Rotate the actuator extender clock wise so shorten overall length.
4. The actuator rod should be half hole length short to the wastegate arm when waste gate is fully shut.
5. Pull the actuator extender towards the exhaust side and securer the extender.
6. Fit the C clip back to waste gate arm.
7. Tighten the extender nut.

That worked for a while. No whistle sound. I finished putting the car back together. Started it up again and no whistle. I went inside to take a shower and change clothes so I could take it for a spin. When I came back out the whistle was there again.

I decided to video and log a trip around the neighbor hood. You can hear the noise most of the time on little or no throttle. It seems to go away once I start accelerating.
Here's my video - I boost it and coast it numerous times. A few of the longer boosts are around 3:25, 3:55, and 6:23.

Attached is my log and tune. Thoughts on the sound? Anything stick out in the log?

It may be that once it heats up, everything expands and seals the leak.

But the noise usually comes back the second I let off the gas...

It sounds like you know where the issue is because you messed around with the WG connection and it went away.

I didn't watch the video above, but try this.

Remove the cotter pin and WG arm. Tighten the rod by turning it the way you did above. Except turn it where it is too short so that you actually have to pull the arm out (away from the can) to reconnect it. It will be difficult, but when done it will really be holding the flapper shut. This will ensure that the flapper isn't some how sitting open just right to cause a whistle.


While I can't imagine it is a friction issue, I have heard a whistle created by metal rubbing together at high frequency. Make sure the WG rod isn't vibrating loosely on the WG flapper rod.

I did that yesterday. I set it so the hole in the arm was about 1/2 of the hole width short, pulled the arm with pliers and connected it. I can make it a twist or two shorter and try again.

I can see by the picture of your turbine wheel that the DP and turbine housing are leaking. Look at all the soot. Just like where the turbine housing and manifold came together.


https://www.miataturbo.net/attachmen...1&d=1349100072

you need an outlet gasket as well.

I actually ordered a gasket this morning along with the correct studs/nuts for this downpipe/turbo. Previous owner did not have right hardware there.

punch him.

hey i was in chesterfield on saturday.

If you're ever down here again, I'd like to borrow some of your time to check out the car, tune, etc. Buy you drinks!

i try to spend as little time as possible in richmond.

me too, that's why i am in west Chesterfield

I showed my video to a couple people separately this weekend and both said within two seconds that the noise is not air, but metal. We're guessing bearings.

Anyone agree or disagree? I searched youtube for a couple hours but did not find any with a similar sound.

I might be looking at a rebuild kit if that would fix the problem, but I'm not sure if I have journal or ball bearing. I guess ball but don't know for sure. How can I tell before tearing down the turbo? Suggestions on where to get the rebuld kit?

I thought the GT2554 was ball bearing. Check one more thing because I am curious.

Pull the intake pipe off the turbo and have someone shut the car off while you are watching it spin. I want to know how quickly it stops.

I may be going backwards now (can't remember the earlier posts). What size oil feed are you using? restrictor? Is the oil feed clear of debris?

Mine whines like hell at high boost, but spins freely and for a long while on shut down. I'm going to run it until it fails.

The oil feed is -4AN. It spins for about 10 seconds, or at least it seemed like it last night, before I took the manifold and turbo out again. I could hear it spin down. I didn't notice any play in the shaft, but I've never checked one before.

And what about the sound? Bearings? Air leak? ???

The sound will be really hard to diagnose through a video. I thought mine was bearings immediately when I heard it. But then after thinking about it. IF the bearings were bad, then the turbo wouldn't spin smoothly after the car is shut down. It would probably stop rather quickly. In my case I thought that maybe under high boost the turbo became oil starved, and it was trashing the bearings. BUT again, I can't imagine bearings holding up for very long in a hot turbo without enough oil. I figure my turbo would have been torn up by now if it were bearings.

Does it spin smoothly by hand, or can you feel any resistance?