Noise after changing intercooler hoses

[TKW#13]

I bought this 1998 gst about a week ago and the hoses on the intercooler pipes were cracking. It has a side mount intercooler and I replaced the hoses w/2.5 in and now there is a different whining type of noise. I checked on some past threads on intercooler piping and the majority was to go with 2.5 in. Oh yeah the noise only happens when I am driving the car hard and the boost kicks in, if I am at a stand still and rev it does not make the noise. Any help is greatly appreciated thank you.

 

[deletrius]

Does it do anything else besides the noise? any stutter? maybe you are just hearing the turbo for the first time...

 

[calcifer]

maybe you are just hearing the turbo for the first time...

That's what I was thinking as well.

 

[TKW#13]

It has a Greddy blow off valve and it was not making this noise until I changed the hoses. If anything it should be better than it was because the other hoses were cracking and most likely losing pressure. Sometimes at about 5k-6k it will sputter a little.

 

[TKW#13]

I also just changed the water pump, all belts, spark plugs, wires, and oil.

 

[calcifer]

Yeah, but what we're saying is the noise might actually be your turbo, which you should be able to hear, although my turbo sounds more like a whistle than a whine I think. It makes sense with what you say though, you won't really build boost free revving, but as soon as the boost hits you hear it. You should only hear the BOV when you let off the gas/shift.

 

[TKW#13]

It makes sense with what you say though, you won't really build boost free revving, but as soon as the boost hits you hear it. You should only hear the BOV when you let off the gas/shift.

Ok I see what you are saying I was not sure. I have friends with turbo cars but I have always had n/a. Thank you for the help.

 

[calcifer]

No problem. It could also be that your turbo has started to die, mine got alot louder about 2 weeks before it started smoking. The timing of changing your IC pipes could just be a coincidence. But let's hope that's not the case!

 

[kmoore]

These "hoses" that you are talking about, are they the couplers that you changed or are they the actual pipes? If you changed your stock plastic PIPES to metal ones then you will definately hear the spooling of the turbo more. Have you done a boost leak test to make sure you don't have any leaks?

 

[TKW#13]

The pipes are metal and there are 5 hard blue rubber pieces about 4in in length to connect all the metal pipes together and to the intercool.

 

[TKW#13]

How or where can you get the pressure test done?

 

[Cs4g63]

This should help. Just go to the intake section.

http://www.vfaq.com/index-main.html

 

[romeen]

How or where can you get the pressure test done?

Make your own:

http://www.dsmtuners.com/forums/showthread.php?t=201554

This is the one I use, works very well. However, you need access to an air compressor. An air/boost leak at one of the blue couplers you describe could cause noise. Even if that is not the cause, occasional boost leaks tests are a good idea. They are the cause of many driveability issues.

Let us know if you need any help with the boost leak test.

 

[kmoore]

Is it a high pitched sucking sound that you are hearing or is it really a whining sound? If its the high pitched sucking sound, you probably already know, it the spooling of your turbo. Also, on the boost leak test make sure you have a boost gauge or have a gauge installed on the tester itself.

 

[TKW#13]

Make your own:

http://www.dsmtuners.com/forums/showthread.php?t=201554

This is the one I use, works very well. However, you need access to an air compressor. An air/boost leak at one of the blue couplers you describe could cause noise. Even if that is not the cause, occasional boost leaks tests are a good idea. They are the cause of many driveability issues.

Let us know if you need any help with the boost leak test.

Thank you, I will try this.

 

[TKW#13]

Is it a high pitched sucking sound that you are hearing or is it really a whining sound? If its the high pitched sucking sound, you probably already know, it the spooling of your turbo. Also, on the boost leak test make sure you have a boost gauge or have a gauge installed on the tester itself.

I did notice on my way to work today that I was only hitting about 9lbs. on my boost gauge isn't stock around 12lbs.?

 

[calcifer]

I did notice on my way to work today that I was only hitting about 9lbs. on my boost gauge isn't stock around 12lbs.?

Stock boost gauge means nothing, get a real boost gauge and see where it's at.

 

[DSMLaser90]

is your couplers loose

 

[EvolvingGST]

No problem. It could also be that your turbo has started to die, mine got alot louder about 2 weeks before it started smoking. The timing of changing your IC pipes could just be a coincidence. But let's hope that's not the case!

would be my guess... whining turbos normally mean they are gonna kick the bucket

 

[TKW#13]

would be my guess... whining turbos normally mean they are gonna kick the bucket

It has a new turbo and it has a boost gauge on the pillar, but it is not a good brand.

 

[deletrius]

yea stock boost pressure is around 12-13 psi. if yours is only pushing 9psi then something is definitely wrong.

 

[TKW#13]

This forum is rad I found a leak, fixed it, now I am running about 12lbs. boost and that wierd noise is gone. Thank you for all the help.

 

[deletrius]

woo hoo! see, we can be helpful sometimes