What is this "zipping" noise my car makes? [Video inside]

[nelliott500]

Had my transmission rebuilt 1.1 by Jack's Transmissions. Just installed it last week. Finished up a bunch of final stuff throughout the week before starting it up. Took quite a few starts and a few breaks to get it running and idling normal. Once I got it running and warmed up a bit, I gave it a rev and around 3k+, I hear this noise:

[ame=http://www.youtube.com/watch?v=U6XpEuQDS-4]Why is my DSM making this noise? - YouTube[/ame]

Any ideas? New 1.1 Jack's Transmissions rebuild, MT-90 trans fluid, new ACT Streetlite flywheel, new Exedy stage 1 clutch, new clutch fork, new OEM TOB, new shimmed pivot ball.

I thought it might be the BOV so I checked and I noticed the hose from BOV to intake was unhooked so I hooked it back up and the noise is still there. I haven't taken the car out yet because the trans won't go into 5th/R. I'm thinking it's either the BOV or maybe compressor surge? The turbo was fine before the car went up on jack stands for a few months.

 

[95DsManiac]

I don't know for sure if both 1g and 2g have the same back up light sensor on the trans, but mine was too tight and it wouldn't allow my tranny to go into 5th/R. Have you checked all your shifter cables? What all exactly was taken off and or put on the car before it made this noise?

Anthony B.

 

[undefined0000]

Whining/whirring really only comes from 2 things. A belt being too tight, or gear teeth pressing up against eachother too hard. Does it do the noise in:

Neutral:Clutch Engaged
or
Neutral and clutch disengaged?
or both?

And yes, check the shift cables, might have something just in the way and never heard of the reverse sensor causing that, definitely a different one.

 

[n0de]

Sounds like a belt

 

[Dsmkauai]

I don't know man really hard to tell from such a short clip. I would think not being able to shift is a major problem, are you sure you aligned the clutch properly, did you install the belts to tight? Check turbo for shaft play just to rule that out! Can you get a better idea of where the sound is coming from? Could be your clutch dragging maybe since its either not adjusted right or something is loose or off causing the shifting problems.

 

[nelliott500]

Ignore the trans not being able to shift into 5th/R. It's strictly a trans problem. Even with the car off, I can't manually move the shift selector/lever into 5th/R.

I don't know for sure if both 1g and 2g have the same back up light sensor on the trans, but mine was too tight and it wouldn't allow my tranny to go into 5th/R. Have you checked all your shifter cables? What all exactly was taken off and or put on the car before it made this noise?

Anthony B.

There is a reverse switch but I can't imagine that would be the issue. There's also the speed sensor.

The trans and everything associated with it was taken off of the car and put back on before this noise happened. I forgot to mention brand new axles too but they shouldn't even be coming in to play since the car hasn't moved.

Whining/whirring really only comes from 2 things. A belt being too tight, or gear teeth pressing up against eachother too hard. Does it do the noise in:

Neutral:Clutch Engaged
or
Neutral and clutch disengaged?
or both?

And yes, check the shift cables, might have something just in the way and never heard of the reverse sensor causing that, definitely a different one.

Shouldn't be any belts. None were removed. I don't know about the whole clutch in/out thing. I'll check that this afternoon. I don't know why I didn't check that.

Sounds like a belt

I agree. I just don't know why since none were removed.

I don't know man really hard to tell from such a short clip. I would think not being able to shift is a major problem, are you sure you aligned the clutch properly, did you install the belts to tight? Check turbo for shaft play just to rule that out! Can you get a better idea of where the sound is coming from? Could be your clutch dragging maybe since its either not adjusted right or something is loose or off causing the shifting problems.

I haven't tried to give the motor throttle while being out of the car so I haven't been able to track down the location of the noise. I haven't adjusted the clutch at all so dragging is a possibility but I think it's unlikely at 3-4k and I have a feeling if it dragging made this much noise, the car would lurch forward but it doesn't.

 

[serviceguy]

The reverse gear switch is a plunger type, if not properly installed it can prevent the tranny to go into reverse and if you force it in reverse it won't come out. The mechanic that replaced the switch on my 1g decided not to install the washer that came with the switch and as a result first I could not put the car in reverse, then I could not take it out. It was an easy diagnosis too since the only thing he changed was the switch due to the original being broken. I never got to try in 5th gear like that but 5th gear and reverse share the same fork.

 

[Colt4G63 also]

The washer missing on the reverse switch is a pretty well documented cause for your shifting problem. As for the whirring noise, it sounds to me like the harmonic balancer is touching the timing cover.

 

[nelliott500]

You guys are the best. I somehow am missing the washer for the reverse switch. I pulled the switch out, noticed the lack of washer, and tried shifting with it out of the car. Went in without any issues. Put all of the linkages back and it shifts no problem. I'll pick up a washer at the dealer tomorrow morning on my way to work.

I did a little more playing around with this "zipping" noise. It does it with the clutch in or out. It only does it when I drop off of the throttle quickly at 3500+ RPM. I took it up to 5k and back down without the noise. I also played around with it while I was under the hood. It sure as shit sounds like it's coming from the BOV. I definitely never had this noise before. I don't mind the noise at all. I just want to make sure it's nothing bad.

 

[nelliott500]

Any other ideas about this noise? It sounds like it's coming from the BOV but it's way too loud to be a stock BOV.

 

[rEclipserGST]

Boost leak, vacuum leak, or something is rubbing. Like mentioned ^ above, check the timing cover & harmonic balancer.

 

[n0de]

Any other ideas about this noise? It sounds like it's coming from the BOV but it's way too loud to be a stock BOV.

Swamp gas from a weather balloon was trapped in a thermal pocket and reflected the light from Venus which resonates at a specific frequency when combined with your engines harmonic frequency at 3k rpm thus causing a zipping noise.

 

[nelliott500]

Could an exhaust leak be the culprit? I did pull my turbo and downpipe off recently. I replaced the gasket for the downpipe but I reused the one for the turbo.

I'll take a look at it again tonight. I picked up the new gasket today for the reverse switch.

I'm ruling out the BOV now. I've pinpointed it to the air filter/MAF. I have what I'm assuming is just a hacked air box that had a K&N filter attached to it, as can be seen in this picture:

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I just want to know if it's anything to worry about though. The car seems to run fine.