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After a little hunting and cramming myself under the decklid I found that the line is loose at the wastegate. I mean, like loose enough that I can twist the accessible end and the line will twist on the wastegate mount. This could be where air is escaping.

While we are on the topic, I found myself asking how this system works. How does the intercooler correlate to the pressure of the wastegate and when it opens? [/QUOTE]

That could be all the problem you have. The WG controls the IC/intake boost pressure; so, diferent spring = diferent pressures. However, with the IC/WG hose disconnected the WG never opens so you're getting full turbo pressure (ways over .8 OEM) W/O any release... and that triggers the switch to shut off the fuel pumps. FYI, Some folks use a manual "control knob" in the cabin to control the boost pressure... big power BUT it's like a monkey with a loaded gun consequences. M2c

Old 10-14-2014, 07:40 AM
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Quote:
Originally Posted by thenewgarage View Post
What is the proper name for this line? Wastegate hose?

any bright ideas on how to get something in there to tighten it without removing the intercooler, etc.?

While we are on the topic, I found myself asking how this system works. How does the intercooler correlate to the pressure of the wastegate and when it opens?
Commonly referred to as the wastegate hose, wastegate "signal" hose, boost "signal" hose.

Really very simple how this works. You floor the gas pedal, exhaust gases spin up the turbine which is connected to the compressor, compressor starts pumping air into the intake, ultimately creating positive pressure within the intake (this will be everywhere after the compressor - i.e. intercooler, intake manifold, and all connected "plumbing"). The wastegate has a diaprahgm which when pressurized via the boost "signal" hose acts against the spring holding the exhaust valve closed. The spring is calibrated to open when the boost pressure reaches a specific level (in stock config = 0.8BAR). When the exhaust valve of the wastegate is open, some of the exhaust gas is allowed to bypass to turbine, so that it doesn't spool up beyond the desired level.

If the hose clamp you want to tighten is not accessible from underneath, you probably should just remove the intercooler. Its easy and if you're going to DIY on this car, you need to learn how to remove it anyway.
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Old 10-14-2014, 08:20 AM
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Thanks jwasbury. Sounds ridiculous but I didn't really think about the pressure throughout the system.

So speaking of pressure ... Shot some more air into the WG. The air I heard is exiting out of the atmosphere opening of the WG. I put a piece of tissue paper by the port way down there in the engine bay and confirmed this assumption.

Thinking about the system ... This would mean the diaphragm in the WG is toast and is there for allowing air to pass through, correct? I did regulate the air pressure.

Another picture for your troubles

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Old 10-14-2014, 03:00 PM
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Quote:
Originally Posted by thenewgarage View Post
So speaking of pressure ... Shot some more air into the WG. The air I heard is exiting out of the atmosphere opening of the WG. I put a piece of tissue paper by the port way down there in the engine bay and confirmed this assumption.

Thinking about the system ... This would mean the diaphragm in the WG is toast and is there for allowing air to pass through, correct?
Good diagnostic procedure there. Based on your description, I'd agree with your diagnosis. The diaphragm is replaceable, could fix your problem entirely, or simply reveal the next weak link in the chain.
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Old 10-14-2014, 04:47 PM
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Dont go buying anything more until youve examined it as a whole

And dont listen to some of these guys ether lol, youll end up spending way tooo much.. theyll have you buying frigging sound mats cos the fan is whistling too loud !
Youll find prob a third of what people say is needed more the case

So Look first And Tissue trick doesnt work unless you silicone the side porthole and cable tie the flux capacitor next to the springy booster knob thing by the shocker nut rocker on the left -portside

But seriously dont buy anything until your sure..
With these cars 99 percent and i mean 99.99 percent of the time the cause of something not working is becvause it is loose and needs tightening, so do that FIRST

No worries

Thankyou
Old 10-14-2014, 07:16 PM
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I had exactly the same issue, but before you carry out all the sound advice given here, you might want to check behind the large vertical IC pipe in the front of your engine bay.

There is a narrow breather pipe that runs behind it. After i'd had a couple of teeth in the dashboard moments, I looked it over and found the breather had come off of one end when I was re-fitting the IC after a service. One hose clamp later.....all sorted
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Old 10-16-2014, 02:39 AM
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Quote:
Originally Posted by dh930turbo View Post
I had exactly the same issue, but before you carry out all the sound advice given here, you might want to check behind the large vertical IC pipe in the front of your engine bay.

There is a narrow breather pipe that runs behind it. After i'd had a couple of teeth in the dashboard moments, I looked it over and found the breather had come off of one end when I was re-fitting the IC after a service. One hose clamp later.....all sorted
dh930,

I am double checking all the hoses. Are you speaking of the waste gate hose?
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Old 10-16-2014, 03:17 PM
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I have pretty much the same issue with my car. My FID (Face In Dash) usually only happens when the car is up to operating temp but the first full boost pull of the day in 2nd and sometime 3rd. If the car is hot or its hot outside the issue is very hard to replicate. For instance it did not occur while on the dyno and that was a full 3rd gear pull.

My thinking is that when the intercooler is cold the air is just dense enough that it creates enough boost to hit the cutoff switch. I am running a bigger B&B intercooler, headers, muffler and TiAL WG which supposedly has a 1 bar spring in it.

The overboost switch in my car looked new when I bought it but I replaced it anyway, same issue (though less frequent).

I replaced both my fuel pumps with 044s and upgraded the wiring, no change in FID.

I have a lug that I can ground the overboost circuit to and test but.....I am seriously to chick***** to test it.

Questions:
1. The overboost switch is supposed to kick in at 1.2bar correct?
2. For those folks running 1bar springs or even more boost, are you just grounding the switch and running bareback with no protection?
3. There are two lines to the WG, one is a signal line from the intercooler and the other is a vent line. The vent line is just open to atmosphere in my car, the thinking being it just needs to be open to allow the underside of the diaphragm to move down correct?
4. I have a small regulated air supply, in theory I should be able to dial in 14psi to the WG signal line off the intercooler and should feel air exit the WG exhaust pipe correct?

If I feel air escaping the vent line we know that the diaphragm is torn thus the WG is not opening creating an overboost condition correct?
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Old 10-16-2014, 04:00 PM
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Quote:
Originally Posted by 16Volt View Post
Questions:
1. The overboost switch is supposed to kick in at 1.2bar correct?
2. For those folks running 1bar springs or even more boost, are you just grounding the switch and running bareback with no protection?
3. There are two lines to the WG, one is a signal line from the intercooler and the other is a vent line. The vent line is just open to atmosphere in my car, the thinking being it just needs to be open to allow the underside of the diaphragm to move down correct?
4. I have a small regulated air supply, in theory I should be able to dial in 14psi to the WG signal line off the intercooler and should feel air exit the WG exhaust pipe correct?

If I feel air escaping the vent line we know that the diaphragm is torn thus the WG is not opening creating an overboost condition correct?
1. Approximately, yes
2. I'll let high boosters answer. I keep mine below 1 bar
3. Yes, line off the top of the WG is vent. Some aftermarket electronic boost controllers use a solenoid valve on the vent hose to hold the wastegate shut until a preset boost level
4. Pressure applied to the wastegate signal line should open the exhaust valve in the wastegate. You should not hear the air you're feeding into the WG escaping from the WG dump pipe. If you do this test with the engine running, you should feel engine exhaust coming out of the WG dump pipe.

Agree that air coming from the WG vent hose during this test is a sign of a failed diaphragm.

As to your overboost problem, it could be "boost creep" where your max boost is spiking above the desired level. Boost creep can occur if the wastegate circuit of the exhaust is not efficient. Keep in mind that the WG spring is calibrated to open at a specific air pressure, but when the wastegate opens it is not bleeding off manifold pressure, it's allowing some of the exhaust gases to bypass the turbine which in turn should reduce the air being pumped into the engine by the compressor. Bottom line is that a 1 bar spring might actually not control boost to that level depending on the efficiency of the wastegate circuit of the exhaust, the turbocharger setup, engine config, etc.
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Old 10-16-2014, 04:50 PM
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16volt,

Very similar symptoms here. Mostly 3rd, sometimes 2nd.

Your last question is exactly what I want to know. If this is correct then this really narrows down the hunt down to the WG!
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Old 10-16-2014, 04:52 PM
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Thanks for the fact check Jacob. I had a Greddy ProfecB boost controller on my Scirocco, cool device. I loved that you could dial in how hard the boost came on with it. I however am totally not mature enough run one on the 930, I would just crank the boost till I hit BEW (BOOM Empty Wallet).

I guess I will finally drag out the compressor and test this weekend. You really shouldnt need the engine engine running though since the spring holds the WG closed and not actual engine vacuum right?
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Old 10-16-2014, 05:32 PM
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You really shouldnt need the engine engine running though since the spring holds the WG closed and not actual engine vacuum right?
I suggested to have the engine running because you can verify if/when the wastegate opens by feeling the exhaust coming from the dump pipe. If the engine is not running, how will you know that the wastegate is open? I don't know your set up. I don't know that you can actually see the wastegate exhaust valve on the factory set up with the wastegate in situ. If you have a stubby after market dump pipe (like this) on your WG, maybe you can get a visual on the valve.

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Old 10-16-2014, 06:26 PM
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Ah, yeah makes sense, no exhaust to bypass. Hmm...guess I will just have to try both or pull the gate entirely.

And yes, mine is just a short dump tube.
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Old 10-16-2014, 11:12 PM
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Quote:
Originally Posted by thenewgarage View Post
dh930,

I am double checking all the hoses. Are you speaking of the waste gate hose?
Hi,

No this is a narrow rubber breather that runs vertically and was obscured by the large oil IC pipe at the front (rear of the car) of the engine bay.

I'm pretty sure it goes to the underside of the IC rad?? I'll check it at the weekend and get a picture.

It could be that the pipe has a split or is losing vacuum under boost conditions?

As I said, mine was not actually connected at the top (I forgot to reconnect it when I re-fitted the IC).

I secured it in place, made sure the hose clamp was nice and tight then tested it.....no more scary risks to my dental work!!
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Old 10-17-2014, 04:09 AM
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So its a little clearer -



In the above diagram the port labeled "Boost Controller" is left open to atmosphere for folks not running an aftermarket boost controller and the "Compressor Reference" port is what connect to the intercooler.

DH930 - think the line you are talking about is the top line. Not sure why or where you would have it plugged into.

Here is the TiAL installation diagram for reference.

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Old 10-17-2014, 01:04 PM
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So here is a little update our 930 that spawned these questions.

After swapping out the over boost switch and testing the WG, Todd (OSI930) helped me determine it is the actual WG diaphragm.

I was nervous about breaking the studs ... but one ruined t shirt with PB Blaster (I went kind of crazy with it) and a can of confidence later I got the waste gate off with no issues. The muffler would not budge though so that stayed on. Negotiated the WG and muffler out of the car and into a box to Todd. He popped it open and found three holes in the diaphragm.

The previous owner of the car did not exercise the WG as it should be. Stuck valve or busted diaphragm, it needed to be replaced.

Todd sent out a rebuilt WG with a dump pipe, which I am pretty excited about, and I should have it installed once it arrives. Now I need to start training my body to handle the forces of acceleration I hope to feel.

As required, more pictures will be on posted once the ol' girl finishes taking her nap.

Big thanks to everyone who has helped so far and to Todd for answering all my questions and concerns!
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Old 10-28-2014, 08:48 AM
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Update?

I havent bothered to test my TiAL gate yet.
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Old 11-04-2014, 04:09 PM
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Todd rules - he's helped me out a number of times off radar

too cool

great to hear it's enroute

report back, preferably with the WOT selfie as the nose lifts to the horizon and yer sphincter puckers to oblivion (sphincter selfie not required)
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Old 11-04-2014, 07:26 PM
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Quote:
Originally Posted by thenewgarage View Post
One more with a ton of glare
Where is this? Porsche City, USA ?
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Old 11-04-2014, 07:40 PM
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Spent some time the garage last night. I found that my compressors regulator isnt really setup for pressures below 25psi. I was able to get what I thought to be 14psi dialed in and hooked into the WG reference line. When I applied pressure I could hear the WG click open, there did not seem to be any leakage anywhere as the WG held pressure.

I snipped the end of the line to get back to good rubber as the hose was looking worn. Buttoned it back up and did a test drive this morning, no change. Hard into the boost and whammo, face in the dash. Ugh.

I guess the next step is either remove the WG and do a closer inspection or wait till I get a real boost gauge in the car.

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Old 11-08-2014, 09:12 AM
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