Weird noise when shifting

[Draghkar]

I just picked up my pumkin, uh I mean Spicey Orange MSP, today So far it's great, but it often makes a strange noise when shifting into 3rd or 4th. Hard sound to describe. Has anyone else had unusual noises when shifting?

 

[SpicyMSP]

yes kind of squeeky for me

 

[Draghkar]

Hmmm, not sure I'd call it squeaky. I'll have to check it out some more tomorrow and see if I can find a way to describe the sound!

Only seems to happen going into 3rd and 4th though for some reason.

 

[BlackMSP]

CHIRP :x

 

[fhexed]

Hey SpicyMSP,

I hear that "squeeky" sound when I'm shifting, it being my first manuel transmission car, I though i just sucked and needed practice. But I still hear it, is that normal?

 

[black03speed]

If it makes the sound when you are on the car accelerating it could be the blow off valve for the turbo.

 

[DistantTea]

Rev the car up fast to about 3200rpms, let off and shift... when you let off you'll hear a *FSHHHIF* sound and maybe a little squeeky squeeky in there.

It has nothing to do with the transmission... accelerate slowly up to 2800rpms and shift and it won't make the sound.

Its either the bypass venting boost back into the lines or its the wastegate. Usually wastegates sound much more chirpy... so I'm thinking its the bypass valve.

I love the sound. It reminds me that even though I'm in break-in I have a turbo under that hood somewhere waiting to be unleashed.

 

[MikeyG_U2]

My car has recently begun making a sound when I shift at moderate to high RPM's (4000+). It's not the bypass valve, which I am very familiar with and can easily identify, it sounds more like a very slight grinding noise. The noise is brief, and doesn't happen when I'm putting the car into gear, but rather as I'm shifting it out gear, by the time I am selecting the next gear, the noise is gone. It's not very high-pitched, at least not to the level of a turbo whine. It's definitely mechanical sounding. My first thought was that maybe it's the synchro's doing some extra work at higher RPM's, but my previous two stick cars (one of which was also a Mazda) have not made this sound.

 

[MikeyG_U2]

Here's another post about somebody hearing transmission sounds as well. A lot of people think it's the bypass valve, but I'm pretty confident that is not what I'm hearing.

http://www.msprotege.com/vbb225/showthread.php?s=&threadid=14609&perpage=20&pagenumber=1

 

[DistantTea]

Ok. For the record...

The turbo makes a "bzzzzrriizzz" sound
The bypass makes a "PHFhhhhiP" sound
The wastegate make a "CHRUiUCK" sound

The wastegate moves exhaust gases around the turbo to stop or retard spooling (to maintain predetermined levels of boost). Its more guteral sounding... much more mechanical than the rushing air sound of the bypass or the faint dentist drill sound of the turbo.

We might be hearing the wastegate opening early in the RPM range to make sure the MSPs don't overboost more than mazda wants. Usually a wastegate won't open until maximum psi has been reached... but since our boost levels are so low its possible the damn thing opens that early because max boost is loaded that early.

Maybe a good way to test is to get a car with a boost guage... rev it up to 3500 and let go, record the sound. Rev it up to 6000 and let go... is it the same sound but louder (which would point to the BPV being both sounds and just scratchier sounding at low rpms) or is the 6000 let go sound completely different.

I don't know. I do know the sound is normal, and that I like it.

 

[AGR]

No squeaks here...all sounds are normal.

 

[nattyboy513]

all i hear is the chimpmunk-like laugh of the by-pass valve/blow-off valve/wastegate

 

[MikeyG_U2]

The sound I have only happens when I shift, not during turbo spin-up, or at any predetermined RPM. I'm hitting a heat wave here in chicago, so I'll drive around with my windows down to see if I can tell anything more after work today.

 

[Draghkar]

Well, at least I'm definitely not the only one hearing sounds. What DistantTea said might be it. I was associating it with depressing the clutch pedal, but it could just be letting off the accelerator. Will have to test that.

 

[MikeyG_U2]

I've tried that, when I simply let off the accelerator, I only hear the bypass valve, not the other grinding-type sound. For me, that only happens when shifting.

 

[brennan]

yea the little "squirral laugh happens when I push the cluch only when I'm accelerating moderatley to fast. It sounds more like a rattle. I was kind a worried but seems it is normal. What do you think?

 

[MikeyG_U2]

It doesn't seem to have any ill-effects, it's just not a sound I'm used to hearing, which makes me uncomfortable.

 

[fhexed]

Uhhh.....sorry, but is it normal?

 

[007Sharky]

Just purchased my MSP last week.
For the record I also have the same noise when shifting.

 

[Ryan]

Ok. For the record...

The turbo makes a "bzzzzrriizzz" sound
The bypass makes a "PHFhhhhiP" sound
The wastegate make a "CHRUiUCK" sound

huh dude, can you make the sound agian pls j/k
My car makes the sound only when shiften hard from first to second. its like a woobly sound almost to me it sounds like the turbo spooling out, and the blow off valve releasing at the same time its kinda a whine with a pfft somewhere in the middle lol.
this reminds me if you guys get a chance download the brian regan full comedy thing off kazaa or whatever you use, there's a part in there where he is describing the sound his car makes to mechanics is Halarious, when you dont know what wrong with your car, ya have to tell the mechanic what kinda sounds its making. what distantea said reminded me of that (hmm)