Is this a vacuum leak?
05-21-2006, 09:49 PM
#1
Racer
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Is this a vacuum leak?
I can hear a sucking sound under the hood. I think it's around the AFM area. As I apply a little throttle (by hand) it makes a sound a bit like sucking through a straw at the end of your milkshake. Kind of a 'sfett, sfett' type of noise (sorry onomatopoeia is note one of my strong points). Anyway as this is my fist turbo I am not sure if this is normal in 951's or if there is a leak there?
My stock boost guage is only making 1bar which is why I am looking around under the hood in the first place.
Thanks for any input,
Simon.
My stock boost guage is only making 1bar which is why I am looking around under the hood in the first place.
Thanks for any input,
Simon.
05-21-2006, 10:16 PM
#2
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You probably have an intercooler hose, throttle body hose or j-boot crack. Your stock gauge should make about 1.8 bar, as the 1 bar is just atmosphere - you have a pretty good leak.
check all the large hose connections, check the j-boot AFM to turbo, check the BOV that hooks into the side of the j-boot(you can pull this off and suck on the top - if you can, it's toast), and check all the little vacuum line connections. good luck.
check all the large hose connections, check the j-boot AFM to turbo, check the BOV that hooks into the side of the j-boot(you can pull this off and suck on the top - if you can, it's toast), and check all the little vacuum line connections. good luck.
05-21-2006, 11:26 PM
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Hey Bret you were spot on with your advice there. I went over every hose and connector I could get easy access too and found that the intercooler hose from the manifold was very loose. Tightened the sucker up, went for a test drive and got my boost back! Just about 1.8 according to the guage. I can't believe I was driving around for a couple of weeks like this. Needless to say the difference is well, remarkable!
The shop that changed out my cam/balance belts obviously had an amateur on the job (very worrying) as the air box was also not even screwed down properly. Now I will go over everything I can to make sure there is nothing else those bozo's missed. It's no wonder so many of us resort to working on our own cars!
Thanks for the help!
Simon.
PS The sucking sound I described is still there, could this be yet another leak or is that normal?
The shop that changed out my cam/balance belts obviously had an amateur on the job (very worrying) as the air box was also not even screwed down properly. Now I will go over everything I can to make sure there is nothing else those bozo's missed. It's no wonder so many of us resort to working on our own cars!
Thanks for the help!
Simon.
PS The sucking sound I described is still there, could this be yet another leak or is that normal?
05-22-2006, 11:49 AM
#4
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This could be several things: o-ring below TB screw, all the little connections on the j-boot, BOV having a small leak. This is where a good boost/vac gauge comes in. Most stock cam cars in good shape, no vac leaks, will have about 17-19" of vacuum at warm idle, idle being +/- 850-950rpm