Ok so I ve searched for an answer to this and it seems that quite a few peopkle have had this happen to them.But it seems like none of them ever posted back as to what the problem was.One guy was somewhat helpfull as he stated that it ended up being a bad solenoid.But he didnt know which one went bad.Im hoping someone sees this and chimes inas to which solenoid was at fault.Thanx.

 

Sounds like your Turbo may have come un-balanced, or suffered catostrophic damage. Or you may just have a major boost leak.

Check all the IC connections as well as the Y-Pipe -crossover tube coupler and Turbo/Y-Pipe flanges for loose nuts.

 

I doubt its that since the problem comes and goes.Sometimes the car pulls all the way to redline and sometimes it doesnt.It sounds like some valve is shutting up and causes this boost restriction.So its either the tca or the ccv.

 

Just do the normal maintenance check.
Start off with all your ic piping. Most of the time its your coupler that has a rip. You can not tell unless you take everything apart and stretch / twist it around. Next check all your hoses from y pipe. If you can rotate it. Then it's not tight enough.
Next would be your vacuum hoses. Check all visible hoses first before taking off UIM. Then check the Check valves. It is rare your solenoids would go bad but possible. Check the Turbo control system. Two on the front of UIM and another under the UIM.
I would bet its the coupler or vacuum hose.

 

when mine did that i had a rip in the coupling, kinda sounded like my vented wastegate not that i think about it.

 

ive had a split coupler as well.This sound is different.
I get full boost in primary until 4500 rpms.Then it drops to 3 psi and doesnt go any higher.It also makes the police siren noise when I let off the gas.
Im just trying to find out which solenoid is at fault.Im pretty sure a few other people have had this same problem.

 

sorry speed, i don't know which one since i didn't fix it myself. good luck.

 

Have you noticed if their is a relationship between this happening vs. whether or not the car is warm or cold?

 

at first it seemed like it was happening when the car warmed up.when the car was cold it would run fine for about 10 to 15 minutes.then the problem would start up once the car was warmed up.now the problem is happening all the time.even if the car is cold.
The one thing I have noticed is that boost sometimes fluctuates rapidly before it drops to 3 psi and stays there.It sounds like some door is opening and closing and then finally stays shut.the problem goes away if I let the car rev down below 3000 rpms.it comes back when I take the car past 4500 rpms.hope this all helps.
At this point i think its the turbo control solenoid above the air control valve.i hope im right.

 

i am having same problem only does it some time please let me know wha tyou find out

 

can you record the sound and post a clip here?

 

If it happens when you let off the gas check your c-clip on the turbo actuator rod that goes to the wastegate on the manifold. I think that being off causes exhaust gas to not fully flow to the 2nd turbo and with cause back pressure and will spin the turbine backwards causing an "Elmo" sound. Or it could be the soleniod connected to the actuator.

~Luke

 

Yeah I would start with the TCS. It's not too hard to change. You can lift the UIM enough to get your finger in there to remove and replace it. Just be sure to cover up the LIM so you don't drop any foreign objects into the engine.

 

Unless something obvious is popping up otherwise, I would be looking to see if the charge control valve is operating properly. The charge control valve is a butterfly valve in the back half of the Y-pipe. It holds the back half of the Y-pipe closed during the primary turbo boost phase and then opens just as the secondary turbo supplies boost. Based on your description of what is happening, your valve may be staying closed during the secondary turbo boost phase. I would check the vacuum lines first and then evaluate whether the solenoid is working.

 

edit... nevermind... i'm a dolt

 

the cold/warm difference could still mean it's a coupler. i went through the same thing and eventually found a split in my silicone coupler. it would be o.k. when cold b/c it was stiffer than when warm. just a warning to check the easy stuff first and then start troubleshooting the difficult crap.

 

thanx everyone for all the input.I just ordered a turbo control solenoid from malloy mazda.49 bucks.not too shabby.I figure its the only solenoid that isnt new underneath the hood.If this doesnt fix the problem It should be the ccv valve and the control system for it.
I have checked all the couplers and havent found any new leaks.The couplers are brand new from hose techniques.All my vacuum lines were changed out not too long ago with silicone ones by myself.everything worked great.
Everything went south when I changed out my injectors.
I had to remove the uim manifold and the air control valve.Ive removed my uim many times without any problems.Eversince I removed the acv things started to act shitty.Now the turbo control solenoid is bolted to the acv.So im thinking that maybe I screwed it up when I was removing it.

 

I should have the part by friday hopefully.Ill post an update asap.To help others that have this same problem.Whats funny is that when I mentioned this to ray crowe at malloy mazda.He said he has the same problem that comes and goes from time to time.
Thats how mine started.And then it became a full blown problem.
I checked all the actuators for missing e clips.The tca was missing the clip and I replaced it.Still didnt fix the problem.It seems that everytime I remove the uim to work on the car and put her back toghether she runs great for a little bit.Then it goes back to acting shitty again.

 

i have found out what my problem was the pill that goes from the y pipe to the black vacume tank came apart and thats what was making the weard train noise was the amount of air running through it i just took the pill out and used some 2 ton epoxy to glue it back together it just came apart cleanley soo i ran a beed of the stuff in the little grove to get it sealed perfectally now it runs like a champ again

 

i think the tcs will fix the problem and youll be happy it was so easy

 

i hope to god youre right surge monster.i could use an easy fix on this car right about now.It seems like everything ive done for the car so far has been a huge pain in the ***.

 

The "pill" or the check valve? There is no pill between the y-pipe and the black vacuum tank.

 

its a one way valve or check valve what ever you want to call it

 

cool

 

for reference: sometimes the actuator while loose may still "operate" the valve because of it catching on the stem. i used to compare the sound in my mind to a fighter jet's engines coming online (F15E's when the ramps drop)

and also the solenoid, but check the damn clip first, it'll save you a lot of time and money.