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Problems With A Massive Boost Leak...


PorBleemo

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Okay, with the purchase of these intercooler hoses from StylinMotors (which besides the initial hurdle, I like a lot) my stage zero is complete. With the sole exception of the fuel pump.

Here is my problem, as soon as the car starts developing boost (gets to 0) you can hear a hissing noise from the engine compartment. As you build RPMs, by 2700RPM or so (the turbo is very slow because of this leak) it becomes very loud. I am extremely confused by what this is because:

  • Whatever it is must be rubber and continously tears, every time I have fixed my wastegate actuator arm and these intercoolers hoses my boost has grown to about 7Psi. But then fallen back to a peak of 4-5Psi. In my mind this eliminates a hole in the intercooler.
  • The only thing left that I know about is the Compressor Bypass Valve, which should not make noise under constant acceleration and the sound does not make a fluttering noise.
I'm stumped, do you guys have any ideas? I have double checked my vacuum hoses and intercooler hoses and they are all on nice and snug.

Thanks in advance!

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I have seen the throttle body screws come loose. The car funs fine because of the vacuum is holding it in place but when the boost starts it blows it off the mounting surface. Just a thought…

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Guest AlvinL

Bump, hopefully someone has an idea for me.

How about disconnecting the BCS to the wastegate and testing out the boost then. Be careful about overboosting as it will set the check engine light. If that seems OK, ask a helper to hold with the brakes in the car as he throttles it while you listen for leaks. Stand off to the side for safety.

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Okay, today I finished installing the intercooler hoses but I couldn't get the remaining vacuum hose that goes under the hose (fresh air I think).

I tried the suggestion about pulling the hose off of the wastegate actuator but that didn't change a thing. The car still builds boost slowly and at very low rates (still about 5Psi @ 2800RPM in 3rd, 1st and 2nd don't do anything). Does this mean that the actuator might have a tear? How hard is it to take this apart?

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Check all the hoses under the throttle body cover. There are several that aren't part of any replacement "kit" but they can still tear and cause big problems. Does the car idle fine? Pull 18hg of vacuum?

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Car idles fine but vacuum is usually between 14 and 16 inches. I am going to spray soap on the TB tree tommorow because several hoses do look old. They don't seem really complex so I think I could replace a lot of them with 4mm silicon.

One problem is the cap with the hole for the boost gauge, it appears to be cheaper and it is breaking down very badly. Unfortunately I'm at a loss of a better solution that will hold better.

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One problem is the cap with the hole for the boost gauge, it appears to be cheaper and it is breaking down very badly. Unfortunately I'm at a loss of a better solution that will hold better.

explain this better please.

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Car idles fine but vacuum is usually between 14 and 16 inches. I am going to spray soap on the TB tree tommorow because several hoses do look old. They don't seem really complex so I think I could replace a lot of them with 4mm silicon.

One problem is the cap with the hole for the boost gauge, it appears to be cheaper and it is breaking down very badly. Unfortunately I'm at a loss of a better solution that will hold better.

You should be using an adapter, not a cap with a hole in it. You can pick them up at O'Reilly in their vacuum assortment section.

I'm not talking about 4mm silicon hoses, I'm talking about the big ones going to the IAC.

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