I've put a boost leak detector on to see if I have any leaks but it doesn't pressurize at all. I'm still getting positive boost on the car but I can't really tell if I'm hitting max boost or not cos I've just had a new clutch and flywheel put in and I'm running them in.

 

Can anyone tell me where to start looking and if anyone knows where there is a good diagram of all the pipework so I can trace them all?

 

Thanks

 

Vijay

Andy Duff, never one to hold back!! :D

 

SparkZ;)

Cheers guys for all the comment.

 

Andy, I just wanted to test my system. I thought the point of these are to find any small boost leaks where you might not necessarily be able to hear it with the engine running. As Stuart showed they do work as he found a split pipe. :)

 

Vijay

Vijay,

 

I did ask for a reason m8 - if you really did have running problems then this may help trace it - ie if air was leaking before the turbo you may have a slightly lean running car etc. Wasn't having a dig honest ;)

 

Best test would be to pressurise the IC inlet pipes in the engine bay (the outer two metal pipes) - this would test the whole pressure system (excluding the turbo but thats all) without putting air into places it shouldn't normally go. This would require a fair amount of work compared with the test you have though....

 

CheerZ,

 

Andy

Originally posted by vijay

Cheers guys for all the comment.

 

Andy, I just wanted to test my system. I thought the point of these are to find any small boost leaks where you might not necessarily be able to hear it with the engine running. As Stuart showed they do work as he found a split pipe. :)

 

Vijay

 

One point about Stuarts little split pipe. This would actually have caused the engine to run rich under vacuum conditions, but lean under boost. The line that was split was the fuel pressure regulator line. If you know how these work then this will make sense, if you don't know how these work, just trust me ;) LOL

Hello Andy,

 

I never took it as a dig;)

 

Cheers for the advice,

 

Vijay

Sorry to hijack you thread Vijay - didn't want to add another boost leak thread...

 

I've got a 'schwoosh' noise immediately when going off throttle/boost at low speed - presume I get it at higher speed too but can't hear it - sounds like boost pressure being dumped to atmosphere (no I haven't got dump valves) - does this indicate any particular area for a likely boost leak? seems to be drivers side around front wheel arch - intercooler?? I'm pretty sure that my 'goosehonk' which is more of a 'bottle top blow' is emanating from there too...I know I should just get on my back and have a poke at it but I have very limited work time/space...

 

The pressure's prob escaping while on throttle/boost but not noticeable as it sounds like constant/background engine noise...

 

Any advice appreciated

 

RobH

Has your car been decatted or have you got an aftermarket air filter or exhaust?

 

These will make it so you can hear the recirculating valves working. That is what the goose honk is too. But it may revert back to a whoosh noise.

 

Or your recircs could be leaking.

 

Mine makes the "whoosh" noise too, you can hear it particually when you are driving in a very closed area, like a country lane with bushes along the side of the road, going through tunnels are streets with parked cars either side.

 

Stuart

Hi UK boys, I thought I would drop by because there seems to be alot of confusion with the boost leak technique. I recomend shooting about 20 psi in the system. Some of you may ask why and that is because you might not leak at 9 psi but if you boost at 15 psi or more you might leak. A clamp or bolt might be tight for 9 psi but not tight enough for 15 psi or more thus you well have a boost leak.

 

I have done the boost leak test on a lot of Z's and you really need 2 people to do this one putting air in while the other listens for leaks. Also the Z32 engine seemd to echo sounds in the engine bay. One time when I was working on Zhounds car we heard a leak by the TB but after searching around a little more we found it was coming from the pipe connecting to the turbo.

 

I now use a seperate boost gauge when doing this test and when the psi hits 20 I stop and watch it drop or not. If it drops then you do have a leak somewhere.

 

If I do come upon this situation I wiggle hoses and listen for a change of tone from the hiss. If the tone chgs. then you found the leak. Another way to do it is spraying a water and soap mixture wit ha spray bottle and then look for sudds if sudds develope and that is where the leak is.

 

Remember if you have old hoses you can chg. them to silicon or add silicon glue to the area where the hose attaches to make a tight seal.

 

And yes it's normal the hear the air whoose around in the engine but if you hear a hiss then you got it leak.

 

Here is a write up with pictures on TT.net

 

http://www.twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=618470

 

I hope I was able to answer some of your questions?

Is such a high PSI safe?

So you look at the boost gauge for the pressure of use the one on the pump?

 

Stuart

Originally posted by SRRAE

Is such a high PSI safe?

So you look at the boost gauge for the pressure of use the one on the pump?

 

Stuart

 

At the race track I run 16 to 18 psi so 20 psi is OK. If you put to much PSI in then you well start blowing off vacumme hoses also XS Engineering does this test before any car get dyno tuned and they push 25 psi.

 

As for the Boost gauge I don't use the one in my Z I use one that measures the amount of PSI I pressurize in the system.

 

I hope this answered your question?