bcs test

[dakmon]

Sorry if this is too simplistic, but I just got my pocketlogger and need to know what the bcs test is suppossed to do. All the other tests are audible from within the car but I am unable to hear anything when I run the bcs test. Does this in itself mean the unit is "bad"? I do have major boost problems (no leaks via leak test). Also, is the car suppossed to be running to identify if the idle switch is working correctly (darkened circle on pocketlogger)? The TDC sensor and the power steering switch indicate to be working but the idle switch does not.
Thanks in advance for the help.

 

[kpt4321]

The BCS should click when you hit the test button. You might not be able to hear it from inside the car, open the hood and have someone listen for it.

However, why does it matter? Just chuck the BCS and get a MBC.

The idle switch indicator dot should change from when you aren't touching the gas to once you start to press it down. I can't remember which color is which, but all that really matters is that it changes. If it's not working, you have to adjust the switch, it's on the rear of the throttle body (1g).

What are your "major boost problems?" What did this leak test consist of?

....Kyle T.
93 TSi AWD "TURBO4"
14b - 12.8 @ 108

 

[dakmon]

Thanks Kyle. I am able to hear the bcs, so I now assume that it is operating correctly (yes I will get an mbc). The boost problems arose more than a year ago and I am unable to figure it out. I did a leak test and found a leak in the turbo (o-ring gasket). That was fixed but it did not give me the power back that the car originally had. I have the factory boost guage and I do not haer the turbo whining like it should, however there is no shaft play. The pictures below show much discoloration but I am assuming that this is normal?

 

[kpt4321]

That turbine wheel looks fine, athough I can't tell if that is some oil around it?

You can't base stuff on the factory boost gauge and what you can "hear," it's not nearly accurate enough. I would suggest you pressure test it again, and make sure it holds all the boost. I doubt it will.

Also, with the factory boost gauge, it's very difficult to tell if you have a boost problem or not. An inexpensive gauge is, well, inexpensive, and also invaluble.


....Kyle T.

 

[dakmon]

Thanks for the info. Kyle. How do I make sure that the boost is holding? In the past I have only listened for leaks without much concern as to the amount of pressure contained within. Is it o.k. to use a tire guage to measure the pressure? How long should it stay pressurized and at what p.s.i.?

Thanks in advance.

 

[kpt4321]

You need a boost gauge, either connected to the pressure tester (my bike pump has one attached) or, better yet, one in the car (this will rquire a second person, or you running fast ).

I would pressurize it to at least 15, maybe 20 psi, and see how quickly it drops. My car, which hods boost pretty well, takes a couple seconds per psi of boost drop at 16 or so psi.

ANY audible boost leak is a possible problem, except for any leaks from the MBC (they're supposed to leak) and *maybe* the stock boost control system. I can't remember if the soleniod is open or closed when it has no power.


...Kyle T.
93 TSi AWD "TURBO4"

 

[Goblin]

Originally posted by kpt4321
why does it matter? Just chuck the BCS and get a MBC.

word.

PS. Oil on the compressor blades is normal if you still have your PCV dumping into your intake, it will also be on the inside of your IC as well.

 

[steve]

Originally posted by kpt4321

ANY audible boost leak is a possible problem, except for any leaks from the MBC (they're supposed to leak) and *maybe* the stock boost control system. I can't remember if the soleniod is open or closed when it has no power.

The only time a MBC should leak is when the pressure exceeds the setting on the ball, then it will leak slightly from the bleed hold used to release captured pressure between the MBC and WGA allowing the WGA to close. The stock BCS is closed when power is off. That's so it doesn't raise the boost level if the wire is disconnected.

Steve

 

[RipperXX]

hey i just thought of something.. if he has the stock turbo etc. couldn't his internal wastegate be openging to soon?

 

[dakmon]

I do have a stock turbo set-up. How would I test to see if the wastegate is opening too soon? I will install a more efficient guage asap.

 

[kpt4321]

That picture is of the turbine wheel, not the compressor wheel, which is why I mentioned it. Also, the PCV does not dump to anywhere that would allow the oil to get on the turbo, it dumps right to the intake manifold. The valve cover vent and the charcoal cannister dump to the turbo intake pipe. At least, that is how it works on a 1g.

I find that my MBC, even when set to like 16 psi, begins to let air past at something like 5-10 psi of manifold pressure. I think that is because the spring need to be compressed more than a faction of an inch to activate the wastegate, but when the car is off, even the tiniest movement of the spring is audible. Either way, just block it off, and look for other leaks.

What exactly would be defined as "too soon?" In my opinion, even 14 psi is the wastegate opening "too soon." He doesn't even have a real boost gauge, so we have no clue what boost he is running.

Also, keep in mind that the stock boost control system is a bleed system, so the WGA sees pressure any time you are in boost, which raises the boost threshold.


.....Kyle T.

 

[Goblin]

Originally posted by kpt4321
The valve cover vent and the charcoal cannister dump to the turbo intake pipe. At least, that is how it works on a 1g.

1)That is the PCV

2)No matter what you call it, it still dumps oil into your intake.

3)I said compressor.

4)Have a nice day.

 

[kpt4321]

There are TWO crankcase vents, both located on the valve cover. One, the PCV, is located on the back of the valve cover and feeds to the intake manifold. The other is located on the side of the valve cover, feeds the turbo intake pipe, and is called the valve cover vent.

You said, and I quote:

"Oil on the compressor blades is normal if you still have your PCV dumping into your intake"

I was merely correcting the fact that you called it the PCV when it is not. The PCV goes to the intake manifold, it is the VC vent that can get oil in the turbo and intercooler.

Yes, it "still dumps oil into your intake," I agree. But I wanted to make sure the right information (VC Vent, not PCV) was represented.

I realize that you said compressor. The question is, why? Nobody said anything about oil or the compressor wheel, let alone oil on the compressor wheel. Were you just kind enough to give us a little bit of DSM trivia?

I think you just made a mistake and thought we were talking about the compressor wheel, when we were talking about the turbine wheel. Not a big deal.

...Kyle T.

 

[dsmturboawd]

guys, you cannot "chuck" the bcs. weather it works or not is not a problem, but it needs to be plugged in. (not vaccum line plugged in)

 

[Goblin]

RTFM, it says PCV. If you go into any parts store and say you need a new PCV nipple they are going to give you the one that goes to the valve cover. I'm not going to get into an "I'm smarter than you" argument over semantics.

The reason I said "Compressor wheel" when I was aware the topic was the exducer wheel was to clear up any confusion about what wheel would tend to have oil on it. A lot of people asking basic questions tend to have partial understandings about what they are asking, they could be aware that oil on one of the wheels is common place just not sure which one it was for the benefit of the unaware. So as to why you feel smart for pointing out that you already knew that and then felt you had to "remind" me the context of the original question is beyond me.

I don't appreciate your condescending tone either it's rather childish.

 

[kpt4321]

That nipple is PART OF THE VALVE COVER, and as such you could not walk into a parts store to order a new piece.

PCV, as I am sure you know, stands for pressure control valve (at least, if I recall correctly . There is no reason to put a "valve" on the vent that goes to the intake pipe, since the intake pipe is at atmospheric pressure. However, a valve is needed on the vent that goes to the intake manifold, so that boost cannot fill the crankcase.

Do not lecture me about a condescending tone. You are using the same tone that I am, and while I agree that it is condescending, the fact that you are participating as well negates your right to critisize me. In fact, I would say that you were the one who started down that road with your numbered post there.

And, speaking of partial understandings, you are using the wrong terminology to describe the turbine wheel. It is not called the exducer wheel, at least not commonly. The primary meaning of exducer is the total overall diameter of either the turbine OR the compressor wheel, it can apply to both the hot and the cold side. Inducer diameter is the distance across top of the blades. Thus, both sides of the turbo have an "exducer."

I did manage to find some obsure Australian site where they seemed to be calling the turbine wheel the exdfucer wheel, but this was one out of over a hundred responses to a search, so I would believe the former definition is the correct one.

I wasn't trying to be an ass, I thought you has simply misread my question and thought I was talkng about the compressor wheel. You are 100% correct that it is normal for the compressor wheel to have oil on it (although, not from the PCV.


...Kyle T.

 

[Defiant]

Originally posted by kpt4321
PCV, as I am sure you know, stands for pressure control valve (at least, if I recall correctly .

Positive Crankcase Ventilation

http://www.hastingsfilter.com/engineering/tsb_94-2r.html

 

[Goblin]

w/e dude, what the hell are we even arguing about?

I don't have any communication problems with my buds when we talk cars and thier parts (and some of them have been working on DSMs for almost a decade) and I don't have problems at work when I'm working on cars. Obviously you and I do but is it really worth arguing about what we call the same parts?

Anyhow, I wasen't being condesending on my numbered post, I was on my way out the door to go up to the lake and poped in to kill five minutes while my friends finished loading the car, you know, brevity.

Anyhow Kyle, this is pointless and we aren't even really arguing about anything valid nor is this productive, so I'm willing to just drop it so we can both contribute to the thread rather than bicker over stupid sh][t.

Peace out.

 

[kpt4321]

Agreed, I logged on with a notion of sending you a PM apoligizing for letting this get out of hand.

Let's just agree that one of those "thingers" on the valve cover is what gets oil into the intake tract.

....Kyle T.