Turbo "phhsssss" or "whoosh" sound--Normal? Silenceable? Help!

[Memark]

So-- Just bought an '05 Touring Convertible, it's both my first experience with PT Cruisers and also with Turbos. That sound it makes, most noticeably when letting off the gas, which I know is desirable for some people, is just not for me. I removed the Mopar BOV, but that didn't make too much difference. I took it to Chrysler, & the head mechanic said, well, that's just the sound turbos make. There is the K & N filter/intake system on there, and the Chrysler guy recommended removing it & going back to the OEM box, said it would make it much quieter -- but that even then, the sound will still be there to some extent. But -- and here's my ray of hope & doubt -- I had test-driven another PT turbo, same year & everything, and it didn't have that sound, or any unusual sounds. So what gives?

I really hope that if there is a fix, that it doesn't make a huge impact on performance or mpg. And I greatly hope that those of you out there who know about this stuff are willing to take the time to share your knowledge here, and I thank you profusely in advance. Because I really like the car but the sound's getting on my nerves. like finding out that a great new girlfriend gnashes her teeth.

Mark

[Chromenut]

Mark, if you're running a "hot air" intake (some think it's a cold air intake but it's just sucking in heat from the engine) then you will definitely hear you turbo when you let off the gas. The BOV is the louder of the two, you take it off and the loud whoosh sound goes away, but with the typhoon intake you get a loud sucking sound when you accelerate and can hear the back pressure on the turbo when you decelerate. Some don't find it that noticeable.

I had the Typhoon for a long time until I started running trace recordings on the car when I was at the track. I saw my first 300' times improve but my overall quarter mile times started to hurt the warmer the engine and/or the weather was. So I took out the typhoon and modified the stock box instead. Was a pretty simple procedure, but sounds like you might not have a stock box? Might be able to find one in a you-pull-it yard...

Here's what it sounds like with both on:

http://www.youtube.com/watch?v=gxMhjcIwnjE

[wwpptc]

"what gives" is obvious. Since the turbo PT without the K&N didn't make the "bad" sounds then you need to get and install a factory air box. They can be found from your dealer, Salvage yard, e-bay, Craigs list ,at times here on this site in the "for sale" section, over at "The Crew", etc.

You may also have a boost leak (or more than one). Thoroughly Check ALL of the hoses (large and small) that you can see that are related to the turbo. Tighten them all as you find them just to be on the safe side. on the small ones, simply put plastis ties on them. This will help your overall performance as well as ensure that you don't have a boost leak.

By the way, if the situation ever really comes up, I would keep the car and get rid of the girlfriend.

Jerry

[wwpptc]

By the way, just exactlly how did you "remove" the bov? Also, you do realize that by doing that you're putting a lot of stress on the turbo everytime you let off the gas. I have a sneaking feeling that since you have a K&N that someone put on before you became the owner, they may have also put an aftermarket or Chrysler "blue plate special" bov on because they wanted the sound and performance of the replacement bov. The bov is there to reduce the "shock load" that feeds back and hits the turbine blades when you let off the gas and the throttle body plate shuts. In other words, the factory "quieter one" is there for a good reason. It's completely up to you at this point.

Jerry

[Chromenut]

I agree with Jerry, especially on searching for any boost leaks. You'll lose some power with those...

[05silverGT]

Hi,

Not sure if you would be interested but I would be willing to trade you my intake box (stock) with filter plus some $ your way for your itnake setup if you do not want it? With the stock intake setup the turbo sound is not very noticable...

I will send you a PM with my info.

Thanks

[Memark]

To Jerry & to Chromenut: thanks very much for the response & info. I sent you guys private messages--did you get them?--Mark

[Chromenut]

Originally Posted by Memark

To Jerry & to Chromenut: thanks very much for the response & info. I sent you guys private messages--did you get them?--Mark

I don't see one in my box...

[Memark]

Dear Chromenut (as I said in the 1st missing email, somehow I have a gut hunch that's not your real name): Wow! That's quite a tutorial you took the time to tap out, thank you so much! I think Chrysler owes you more than a few favors--and maybe me too.

So, in line with getting to the bottom of this: it's an auto tranny, the bothersome sound happens pretty much only, and whenever, I let up on the gas, it varies in loudness & duration in proportion to how hard it was gunned, and yeah it only lasts a second, sounding like the sound on your clip at 0:45 & 1:00--maybe it's the same sound? When I took off the bov I simply put the "cover" back on which I believe is what you refer to as the block-off plate, but there was no gasket, the only gasket there was was the one from the bov. Maybe something's missing there?

Thanks also for the offer of the link to the service manuals etc, that would be great. By the way, what's a fair asking price for the bov?

Thanks again, and looking forward to your response--Mark

memark3@juno.com

[Kawizx9r]

I posted this in another thread but just a headsup, I have a stock airbox that I was giving away. About to throw it away honestly. I've got a drop in K&N filter for the stock airbox too (less than 350 miles, costs 38-45 brand new), where are you located?