Team MightyBoy

A bizarre question, but hopefully one that will get you reading and helping me out. So I'm trying to diagnose my turbo spooling (or lack of spool) issues, and was going through replacing some vacuum lines tonight. I got to the intake manifold and was fitting a couple of new lines when I thought I make sure none of them were blocked or anything like that. What I did find was that the red nipple that goes into the intake manifold (and which you can see pictured below, after I shamelessly took a pic found on the Club Cappuccino site).



Question is this: should I be able to blow into this nipple and into the intake manifold? As I can definitely do that. I kind of expect you should be able to, as this line is T'd off to go to my boost gauge, but rather hope you might tell me, "No! That's going to cause you a huge boost leak if you can blow through there!"

If your boost gauge is hooked up to that line then yes you should be able to blow through it and into the intake manifold.

if everything looks ok vacuum wise, check the turbine wheel for any missing fins.

If you boost gauge also reads vac, you should have a look at the idle vac & see what it is - then compare that with a manual to see if your ok in that regards. If so, you won't have any leaks at vac or low boost pressure......

Cheers

ToranaGuy

Mate that's only true if the leak is after the TB. A leak anywhere beween the turbo and TB (including intercooler) won't have any effect on vacuum readings.

ToranaGuy wrote:If you boost gauge also reads vac, you should have a look at the idle vac & see what it is - then compare that with a manual to see if your ok in that regards. If so, you won't have any leaks at vac or low boost pressure......

Cheers

ToranaGuy

Idle vacuum is just under -0.5bar, which is right where it should be.

Brayden wrote:Mate that's only true if the leak is after the TB. A leak anywhere beween the turbo and TB (including intercooler) won't have any effect on vacuum readings.

Yes, i probably should have written a little more detail. But it can narrow down the places to look for leaks considerably!

Soldave advises idle vac is where it should be. So it looks like the issue could be found between the turbo & the TB. It would be great if the gauge could be hooked up between the turbo & the TB, see what readings you get there.

Cheers

ToranaGuy

ToranaGuy wrote:It would be great if the gauge could be hooked up between the turbo & the TB, see what readings you get there.

No reading of any use, I can tell you that much!

Brayden wrote:

ToranaGuy wrote:It would be great if the gauge could be hooked up between the turbo & the TB, see what readings you get there.

No reading of any use, I can tell you that much!

What about when the turbo spools up? Wouldn't you see some boost pressure, if the turbo is spooling up? You wouldn't be looking for an accurate figure as much as just the fact that as the rev's pick up & the turbo spools up you start to see the gauge swing from 0 to some sort of positive pressure? Unless there is a leak or the turbo isn't spooling up enough to make boost?

Wouldn't the gauge sit on 0 at idle?

Cheers

ToranaGuy

My point was that a gauge hooked up before the TB would tell you less than one connected after the TB, so it would be an exercise in futility.