How to troubleshoot the Wastgate or N75 valve problem?
07-10-2002, 06:48 AM
#1
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How to troubleshoot the Wastgate or N75 valve problem?
There are two TT's that are exhibiting very similar problem. One happens to be mine.
Symptoms:
Boost is very erratic. Can get up to 21psi and then next shift only boost to 14psi and holds there. I would assume since I can get to 21psi, which would rule out a hose leak.
Whooshing sound: Any throttle, whether WOT on slow acceleration results in a "whooshing" sound emanating from where the turbo area in the engine.
Burning smell: Both cars exhibit burning smell at WOT.
Details: Both cars are 225 running the GIAC X-chip, but had same issues when the regular GIAC chip was in.
Thoughts: My basic thought is this. The wastegate is staying open, hence the whooshing sound. I am still hitting 21psi but the turbo is being overworked to reach the CMD pressure, hence the burning smell. At some point it goes into "limp" mode and holds back boost.
How would I determine this via a VAG or normal troubleshooting? Obviously swapping the wastegate is impossible since it is internal. Would the N75 be the same on a 225 or 180?
TIA
Symptoms:
Boost is very erratic. Can get up to 21psi and then next shift only boost to 14psi and holds there. I would assume since I can get to 21psi, which would rule out a hose leak.
Whooshing sound: Any throttle, whether WOT on slow acceleration results in a "whooshing" sound emanating from where the turbo area in the engine.
Burning smell: Both cars exhibit burning smell at WOT.
Details: Both cars are 225 running the GIAC X-chip, but had same issues when the regular GIAC chip was in.
Thoughts: My basic thought is this. The wastegate is staying open, hence the whooshing sound. I am still hitting 21psi but the turbo is being overworked to reach the CMD pressure, hence the burning smell. At some point it goes into "limp" mode and holds back boost.
How would I determine this via a VAG or normal troubleshooting? Obviously swapping the wastegate is impossible since it is internal. Would the N75 be the same on a 225 or 180?
TIA
07-10-2002, 09:05 AM
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i think a leaky BPV will be more audible, have you looked into that?
also you might have a broken hose or a leak somewhere causing your engine to run lean/rich thats why it smells
07-10-2002, 09:46 AM
#3
My sound is coming from a different local.
Where as I here my DV working through my intake (drivers side on a TT) the "boost leak" is more audible from the pass side. Plus I sawpped BPV from turbo XS back tothe forge 006 no difference.
07-10-2002, 10:06 AM
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Yeah, ran a Forge now a TurboSmart...
I have been speaking with them to see if it is the DV. But just lubricated it and sound is still there.
The smell is not "that" bad. Most of my hoses have been replaced with silicone and checked.
Still, I will swap my DV again to rule it out.
Was just wondering if there was some way to check what some VAG values should be and what are my actuall.
The smell is not "that" bad. Most of my hoses have been replaced with silicone and checked.
Still, I will swap my DV again to rule it out.
Was just wondering if there was some way to check what some VAG values should be and what are my actuall.
07-10-2002, 10:11 AM
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try this..........
i had a soldering problem with a chip & it had the same symptoms as you're describing
are you just switching the chip's on the socket, of are you using a diffrent ECU?
your best bet would be to get a stock ECU that has not been chipped & see if the problem is still there, then you know whether its the chip or car
are you just switching the chip's on the socket, of are you using a diffrent ECU?
your best bet would be to get a stock ECU that has not been chipped & see if the problem is still there, then you know whether its the chip or car
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07-10-2002, 10:23 AM
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Re: try this..........
I know Rob has swapped chips or ECU's.
I had a bad solder once before, sent it bac to PES and they re-solder the whole thing. Since then, I have just changed sockets to the Xchip, but again, the sound was there before.
Hmmm..
I had a bad solder once before, sent it bac to PES and they re-solder the whole thing. Since then, I have just changed sockets to the Xchip, but again, the sound was there before.
Hmmm..
07-10-2002, 11:37 AM
#10
So it sounded like a boost leak when acceleration?
Blueshirtt's and my problem may be the same. I am hearing what sounds like a boost leak under acceleration. I think it is a bad wastegate or one that is opening prematurely. Where syptoms similar.
See you have the T-28 who did the chip A.W.E? Mine was done by PES.
Thanks!
See you have the T-28 who did the chip A.W.E? Mine was done by PES.
Thanks!