ibkevin

should it hold vacuum?

UK952

Well we tested mine and a friends the other week and they dont hold pressure, I guess so that they can bleed some air to open (not sure if it was the side or top, but one port did and one didn't)
Tony

ibkevin

I just read in the install instructions that the boost pressure line is supposed to be attached to the side port, that means that it should not leak off pressure. Right?

KuHL 951

Along the same topic. Is any Hi-temp thread sealant required or recommended on the tapered threads of the barbs for the Tial?

ibkevin

Ok, this problem is starting to get a little old.

As suggested I ported the banjo bolt directly to the side port, boost is still aobut 1 bar on the dash gage.
Boost control lines to the tial are tight, but a vac test on the side port line does not hold for squat.
There's NO evidence of leakage around any of the mounting plates.

Obviously changing ebc settings will have no effect, I had suspected a bad servomotor, and boost peak recording on the ebc is now bypassed.

Anyone hear of a Tial diaphram rupturing?

Coolant is new and looks good.
Oil is new and looks good.

I can shoot a Quicktime if that helps.

Thanks

ibkevin

136 views with only one input and one question???

KuHL 951

Kevin I just tested a brand new one. The side port holds vacuum briefly (2-3 sec) with the top port open then bleeds. With the top port plugged, it holds but don't plug that it for normal use. I can move the diaphram by sucking on the hose but then it bleeds off. FWIW the allens on mine were loose and one was completely off when mine shipped. Make sure all of them are very tight. Are you sure the WG is your problem with 1 bar?

ibkevin

Thanks Steve.

That's the thing. Turbo makes boost starting at ~ .5 bar, at ~ .8 bar the leak is very noticeable, at ~1.1 bar the noise is the loudest it get's no louder no matter how much throttle I give it. Acts like a leak, sounds like a leak, gotta be a leak.

Here's the ??? What can pass a bar's worth of air that didn't leak while pressing up the charge circuit? The only things we found leaking while pressing the charge circuit were the AOS seals and the top of the evap temp control switch, but those are not under boost!

I've had most of the stuff off the top and drivers side of the engine in the past month, even did a lower balance shaft front seal that the old seal's ID was way expanded, and the dis-assembly inspection looked good. That's why I started questioning items I hadn't inspected, EBC circuit and the Tial. That's also when I started suspecting in internal failure of the newly rebuilt turbo.

I recon' I'll PM a few of the remaining technical minds.

KuHL 951

Are you saying your OE boost gauge says 1.1 bar or you hear the noise loudest at 16 psi of actual boost? If it's a hiss at 16psi I had a noisy leak from my HVAC in the cab after doing a venturi delete; turned out the check valve for the brakes was no longer in line with the AC/heater controls causing boost to get into a device made only for vacuum. You might trace down that small black tube to the heater entering through the firewall near the battery. It has to be after the check valve. Just a thought

ibkevin

Peak boost recorder on the Profec has been a max of 5 psi, and I want to avoid road time diagnosing this to prevent any real damage.

I'll go vac test the check valve/vac res/hvac circuit.

This thing is way bigger than a hiss, if the turbo is running correctly, I figure I'm venting about a bar's worth at around 3500-4000 rpm's. Maybe a second set of ears in the car will triangulate this.

jacklet

check for exh leaks make sure your lines vac and pressure are all good and secure-i had a small split in a boost line once opened up under pressure-by-pass the ebc and see what pressure the tial dumps at should be spring pressure remove the diverter valve and make sure it's functioning properly don't just pull a vac on it-pull a vac on it and make sure it's opening and closing properly

toddk911

"Anyone hear of a Tial diaphram rupturing?"

No, but also was told if a WG diaphram does then would have TONS of boost.

Usually if boost is made and then at higher levels a leak is noticable, it is a small very small leak that allows mild pressure up to a "breaking point" and then acts as a bleed for the boost.

I had that before. Was running 18psi and and then started to run up to and hold only 15psi. Turned out to be a small leak in the IC pipe/hose connector. So the leak was ok till 15, then would start to open up/stretch I guess.

ibkevin

Vac circuit, tested from the brake booster side of the check valve holds a steady 15" for over a minute.

BOV dia travels correctly and does not leak by with puny lung pressure.

Seems to me that if the crossover tube were providing pressure to the valve face of the Tial, and the diaphram had failed, the pressure port (side) of the Tial could not maintain pressure to actuate the valve. Creating a stall in the turbine hot side???

Maybe pressing isolated sections of the charging circuit are required.

ibkevin

I agree, this rules out the WG.

E-man930

the slow leak you are experiencing is normal on the tial. they are like that brand new...