half boost
 

the other day I went to go work when I turned my 99 gst on the sevice engine light came on. Then when I started to drive it the booste would only get up to half on the gauge. And I hear a whistling noise. I checked the turbo and It's fine. any help would be good.

RE: half boost
 

how did you check the turbo? cause thats what it sounds like it is. mine and friends did the same thing.

RE: half boost
 

I took off the intake off and the turbine isn't loose and they move freely but not overly loose. could it be a leaky bov or something?

RE: half boost
 

sounds like you have a vacuum leak somewhere. checked all lines leading to ur IC piping or the IC piping itself?...I've had problems in the past with a hole somehow mysteriously appearing on my upper piping...

RE: half boost
 

the wheel will spin freely even if the turbgo is gone. take the intake back off and take a pair of pliers grab the end of the wheel by the little nut. and wiggle it in and out if it moves in and out more then just very very little then it has shaft play and is gone. the winning sounds kinda like a old fire truck or something right.

RE: half boost
 

does the car spit and sputter like is out of timming. every time i have had a vacuum leak my car would run like crap. so if its just winning i would check the turbo again, if thats good then do a boost leak test.

RE: half boost
 

I'm with Spyderman on this one. I think it may just be a leak in the system, possibly the intercooler piping or even the intercooler if you're un-lucky enough. You can do a pressure test from the upper IC pipe to the lower IC pipe to be certain. Since the Problem came all at once, then i'd say it's most likely a hole in the system somewhere, or even the BOV. Just gotta try pressure test everything....Spyderman's got it.

RE: half boost
 

haha work on DSM's long enough and you realize the same stuff happens to all of them.....there is always room for something new though...lol

RE: half boost
 

I took off the intercooler piping ad cleaned it up and wrapped it in to good old Duct tape. It seems to have fixed the problem I get full boost again. But my check engine light says I need an o2 sensor. Only pro is thre are two diffrent ones. anyone know what one wears out more fequently.

Thanks all of you for you help

RE: half boost
 

go get the codes read....if it says bank 1 then its the one in your oxygen housing on the turbo.....if its bank 2 then its the one in the midpipe...

RE: half boost
 

If you were running half boost and the check engine light came on, then you may have been running rich. Running rich will most likely cause the manifold o2 sensor to get covered in unburned fuel. That will throw a code, but it doesn't mean the sensor is bad just malfunctioning. You can usually just clean off the sensor, and it will work perfectly. But hey, now's as good a time as any to move to a wideband!

RE: half boost
 

what is a good way to clean the sensor?

RE: half boost
 

I dont know if youve fixed this yet or not since its been awhile but gauranteed its your intake manifold gasket

RE: half boost
 

What I did to try and fix the problem is I got all metal ic piping. going from te turbo all the way to the intake. I also put in a Greddy type s bov and booste gauge. It kinid of fixed the problem. After I had the pro shop put the bov and guage in I could get up 15psi everynow and then. now I cant get higher then 11 or 12psi. my question now is that when I have it at 11psi or so and keep the gas down it feels like the car is pulsing. is this normal or shoud I start to look for a new turbo( that I dont have the money for)?

RE: half boost
 

It may not be your turbo. Do you have an air compressor? If so you should do a leak test. What you have to do for that is go to like Home Depot or Lowes or something like that and get a hard rubber coupler about 3-4 inches long which has the inner diameter equal to that of your turbos outside diameter inlet. Follow me? Now you need a pvc cap piece to fit inside that hard rubber coupler. Then clamp it in. Now you need to put a schrader valve, like your car tire valve, in the middle of that pvc cap. Drill a hole in the middle of the cap and thread it in. Do you have a mental picture of what im talking about??? Now put the open end of the coupler onto the inlet of your turbo. Clamp that on. now hook up a compressor to that schrader valve to pressurize the system. Only hold it on there for about 8 seconds then take it off. Now squirt a little soapy water on all of the intake system, if the leak is big enough you will hear air escaping. Now just track down the leak. Do you know all of this allready?????