Does anyone have any idea what is wrong when a squeeling sound occurs during secondary turbos running?

I know this post is a bit vague, but thats the only way I can describe it. Thanks.

 

couplers? intake hoses?

 

I hope, but its pretty loud and almost sounds like metal on metal.

 

ACV (check the filter in the middle of the ACV too), and what have you done to your car lately?

 

well you know what metal on metal is...
death whine... shaft potentially is shot...it's so hard to see the secondaries and feel for shaft play...

 

My secondary turbo was replaced bymy mechanic, this is the first time since my engine has brokein for me to test it. Im hoping its not the turbo. Its kinda of a whistling sound.

 

what is the ACV? t hanks.

 

yes I know that... but didn't you buy used turbo's ????

My new..yes NEW MAZDA turbos lasted a whole 8k miles for me... and I never went over 12 psi and usually ran 10...

hoping my 99's last longer...

whistling.. is way different than metal on metal... I hope for you it's whistling because that could just be a boost leak somewhere.. An ACV is an Air Control Valve...my gut says it's not that...or atleast the ACV I am thinking of.

 

I bought a set of used turbos that were bought from the dealer in 1999. the primary turbo was good, housing was perfect. It had like under 25K miles or so. the secondary turbo was bad. My mechanice took my good secondary turbo and replaced the secondary turbo on the housing of the turbos I bought.

Im gonna be talking to him today to see what he says.

 

Doesn't that secondary have like 160k miles on it?

How long was your break in? just curious.

 

I think you hose is cracking. It happen on my car before.

 

Yea, it has like 160, but had no shaft play and worked fine on my old set up. I broke the car in for 500 miles (under 4K rpm, 3K usual). Then the next 500 miles work in 5-6200 rpm. at 1000 miles gets tuned and oil changed.

 

what hose? please elaborate, thanks!

 

There is a huge difference between the sound of a boost leak and the sound of metal on metal contact. Let your mechanic or another 7 owner drive it and it will be very obvious what is going on. If you are getting full boost during the noise they a boost leak doesn't make sense unless you have the boost set really high.

Guys could the TCA butterfly get stuck sometimes on the y pipe? That's all I can really think of except for blown turbos. I would also advise not driving the car until you figure out what it is.

 

I get a squealing noise under 50% throttle when the engine is cold but it sounds like some kind of valve is fluttering. When the car is warm no noise.

May be it's a worn shaft of the secondary that when cold doesn't have sufficient oil to keep it from wobbling?

doesn't matter though cause I'm replacing the engine and turbo next month.

 

I drove the car today and found that the noise occures between 5500 and 6500 rpm. it goes away after that, even under full boost. Boost is stable and spools fast.

I know 100 pct that the turbo was in perfect condition, but it was transplanted from one set of turbos to another, so I dont know.

 

incase someone pulls this up in a search, it was the lower IC pipe that connects to the y PIPE. The cuppler was loose.

 

i have the exact same problem in mine. it starts at 4500 and goes to 7000.
i took it to a performance shop and they told me that the BOVs are going out probably.

 

this might be far fetched and completely wrong but do you think that the paticular load that happens when the secondary comes online over stresses the belts and causes them to slip a little bit?

 

sqealing noise can also be attributed to a nasty exhaust leak. i had the same problem, but it was because i was running a 3" DP into the stock exhaust. do you have an aftermarket DP going to a smaller exhaust? also if you have any gaskets going from the exhaust mani to the turbo, maybe give those a check. also like everyone else is saying check the boost levels

 

My problem was fixed as I noted above.

 

can anyone answer that?

 

I have bad news for you, Johnny, my brand new '99 J-spec twins bought from SR Motorsports are failing. I have ~9500 miles and 9 months on them. I've checked to see if the low boost stems for a control problem. The boost is 7-8 psi primary from 2500 to 4500 rpm; drops to atmospheric at the transition rpm; and climbs to 3-4 psi to redline. I do hear a dull whining noise when the seoncdary comes online.

FWIW, the car pulls decently despite only 3-4 psi at full tilt boogie. Must be the new street ported KDR, GReddy 2-row FMIC/Airinx (also 9500 miles old). Still the car was much stronger when we were making 0.90 kg/cm^2 (which is merely 12.8 psi).

Like you, I'm stumped as to why the secondary turbo would fail so prematurely (9500 miles is not that many miles on NEW turbos?).

I've submitted a warranty claim to SR Motorsports. Did you have any luck with a warranty claim for the shop you bought your new Mazda twins from? What did they say when you reported your premature turbo failure?

At this point, I'm not sure what to do. I was thinking of trying a set of Stage 3 BNRs from Rx7 Store, but have read horror stories of oiling problems.

I'm not interested in single turbo, or going back to stock US-spec twins. The J-specs have been outstanding up until the recent low boost problems I've had.

 

Just to follow up on the post above. I removed the intake compressor elbow from the secondary turbo and checked the compressors radial shaft play. There is some up and down movement, but it's not very much. I'd say this is normal shaft play. I turned the secondary compressor wheel with my finger tips. There was not much resistance, and the bearing turned very smoothly without any raspiness. I snugged down the lower 10-mm flange bolt on the CCA/Efini Elbow. I cannot say with 100% certainty the J-spec twins are bad at this point. Unfortunately my boost problem still exists. The pattern is 8-0-4. The only part of the turbo control system I have not replaced is the charge control actuator. Not entirely sure this is bad, since it's not clear whether the CCA rod should be pushed in or out when the motor is off. The rod is pushed in when the motor is running.

 

Greg of SR Motorsports will check with Mazda to see what, if any, warranty exists for the '99 Japan Spec twins.