<RANT>
OH noes!

The dreaded 'look for boost leaks' answer, which is ALWAYS given when someone has boost issues...

1) You can't see air.
2) There is no methodology for 'looking' @ boost leaks that is effective, yes I searched!
3) Unless it's 100% obvious you can't tell defective couplers.

It's no wonder theres so many badly boosting FD's on this forum (mine included).

The system isn't that complex, the testing methods are too VAGUE!!

</RANT>

 

Soapy water works wonders

 

vacuum leaks are easy to spot with propane. boost leaks are sort of a experience required deal to spot. ive used some...interesting methods to find boost leaks. from using single ply toliet paper secured around a suspect (sometimes mositened), which will tear from the air if its escaping, to looking for oil (when i had a blown turbo...) getting passed a connection.

 

DUDE!

I've never heard of the toilet paper trick! It's never been mentioned in the 100767765 threads that say, 'LOOK for a boost leak.'

See, thats something definite I can try. What else?

How do you use propane to check for vacuum leaks?

 

the vacuum leak will draw in propane. propane burns faster than gasoline. so you will hear your motor jump (rev a little higher). you basically take a propane torch, open the valve and let the gas out and aim in around suspect areas.

 

Tried that. It just runs off the sides/bottom of anyplace 'round.'

Also, it's tough to apply soapy water, produce boost and look for bubbles in an already bubbly area.

What happens if you car doesn't make the usual 4PSI @ WOT in neutral?

 

Cool, I use starter spray, but same idea.

Now if boost leaks were so easy to spot.

 

1. Agree
2&3. Pull off each of the boost couplers and carefully inspect each one. These are where the great majority of boost leaks happen, and a defective one can, as you said, be REALLY hard to spot while in place.

Dave

 

Sorry, that answer isn't going to cut it. I need to know exactly what makes a good coupler and what doesn't.

The obvious stuff like 'cracks/splits etc etc' are fine. But what about things like couplers that only fail when they're warm, or pressure is applied (how do you apply this heat/pressure?)

I need definite answers, not the same vague 'check/look/inspect' answers. WHAT am I looking for. WHAT am I inspecting for.

HOW do I check?

 

one way to help PREVENT them is too make a bead on the end of the pipe. This can be welded or rolled with a machine. Then slide the hose over it then clamp down past the bead.



-Bead |*| <- clamp
__**_|_|___
**********
*
***********


if that makes sense

 

You can use doctor's stethoscope, or simply a hollow piece of pipe if it will fit in the area, to isolate a coupler and listen for the pressurized air escaping. If you need to get an idea of what this will sound like, create your own boost leak by partially disconnecting a coupler.


-s-
PS, noobs aren't allowed rants, but you're not exactly a newb anymore. I learned the soapy water trick in junior high school, when fixing a flat bike tire.

Edit: Low Impedence, your text diagrams will look a lot better if you use the ['code'] feature of the forums, it's just like the ['quote'] or ['img'] features. Unfortuneately, I can't see what you're trying to show us...

 

It's good or it isn't! If it isn't split, the coupler is fine. It doesn't magically start leaking just because it gets hot. If it slips out of the clamp while hot, it isn't going to magically slip back in the clamp when cold.

Looking for a boost leak is just that. 90+% of boost leaks are due to a split coupler, a popped off or split vacuum line, or a split/failed check valve. These are all checkable with no special tools or skills, even if it's a PITA.

 

^rynberg has it. This isnt rocket science. You just gotta get down and get dirty and take off all the couplers, move them around a bunch, and thats that.

You just dont wanna dig around and get that Y-Pipe coupler off, do ya?

 

Ehos, It is a pain in the ***, just like a lot of things on this car. If you can't deal with it, pay a mechanic, or get another car. Everyone has to deal with a leak from time to time.

 

Guys, Like I posted before I've removed everything at least 4 times (IC install, new duct, when I took off the airpump, and the first time).

So they've been off and on many times. I think I might have a leak in the 'hard' lines (ie the turbo inlet that is at the back side of the engine, theres 2 10mm nuts that hold it on?)

 

It sounds like you've only looked at the path from the turbos to the throttle body. What about the pressure chamber and rat's nest?

Believe me, I know this is a PITA. The two times I have had a boost control problem and couldn't immediately see the cause, I just had my mechanic look at it. It was worth paying an hour of labor each time to avoid me having to spend MORE than an hour of labor trying to figure it out. The other times I've had boost leaks, it was due to a) bad coupler/loose coupler, b) untightened AWS hose blown off, and c) bov hose blew off y-pipe. Those were easy to find and fix.

 

Did it boost fine before you installed the ebay intercooler? If so then you screwed up or ripped something during your install. If it didn't work before then its time to take things apart and investigate the problem. I wish I could just tell you to replace hose "x" on rat nest solinoid"y" and you will have full boost but with these cars its not that simple. If you still can't find it then I would suggest getting a power fc and deleting 90% of the vacuum hoses under your intake plenum hoping that it solves your problem or the cheaper route is ordering new couplers and good ones. Throw out the cheap couplers that came with the intercooler and get the proper silicon ones.

R.K.

 

Hey Rad!

It didn't boost properly before. I thought it was the old couplers (they were pretty grimy), but nope. I ordered some new solenoids and I want to redo the vacuum hoses and go through the car myself again.

Installing the new IC/Duct/intakes/dp helped to make more boost. I was a bit delusional and thought the downpipe would fix everything.

It was making almost 0 boost before 4500 before...I thought my main cat might be plugged (but the 11 PSI run makes me rule that out now..)

jp

 

how about trying smoke machines, maybe you can have a shop do it, mostly used to find leaks in the evap system on vehicles, so if you have a tiny or big leak you'll find it or at least point out the area where the leak is... good luck on fixing the power leak.

 

The primary turbo must make at least 7psi for the sequential system to work. My guess is that it doesn't even transition to the secondary turbo at 4500rpm, correct? If thats the case then I would suspect that one of the solinoids in the rats nest is hooped.

R.K.

 

The easyest/chearest way to find boost leaks.....

Custom tools

 

That's what I USED to think. I don't know what to think now. My car makes 4 PSI before 4500, then all of a sudden, 7.5-8 PSI @ transition all the way to redline.

With the WG line off it goes to 11PSI @ 4500 (almost all the way to redline).

My hoses arrived today so I'll be going indepth today

 

PERFECT!! That's what I need to make!! What did you make them from? (And what fittings?)


/runs to the garage..

 

Try this for not being vague, if you have a coupler that's worth a **** when you turn it inside out it won't split, crack or deteriorate (I.E. you have to use the best tools you have (your eyes and feel) I would say common sense but if sense were common everyone would have it. When they say take it off and look at it they mean move it around, flex it pull on it, feel for cracks if the rubber is hard it will crack (when warm seperate) when cold hold enough boost to appear to work. Don't be afraid to damage it because if you can it's no good. Your inspecting for bad hoses and if there bad you'll know it. Hope this helps. Jack

 

You don't generate boost from this pipe you speak of it's the secondary turbo inlet pipe.....you'll notice it connects to the air filter box....so no boost from there.