No boost at all :(

[mja]

It's a chronic thing, not acute. Only on boost the crankcase pressurizes without the poppet. Over time it starves bearings and weakens seals, you may not even know its gone until something really bad finally happens. The rupture disk was meant to blow before that point, but I'm aware there was a new design in the 2nd or 3rd year, and the new disks dont blow as much now. It could in theory break just about anything connected to an oil passage.

Also, your main seal blew out and was replaced by dealer, right?

 

[mja]

The only code I ever got after the check valve disappearing was that P0238 code. When I tried to pass the semi. It was a random isolated event which I assume was due to not tightening the intake manifold bolts enough. After I did that I haven't had any more codes. The whole losing power and what I thought was no boost was what Jerry said was likely turbo surge or something like that. Since then he's changed the tune on my car and now it sounds great, but isn't nearly as quick as before. It also hasn't really lost power lately. The only thing that has happened is that the car stalled while not in gear, which it had done while the check valve was missing. I don't know why. But it doesn't happen nearly as often to diagnose it. It just catches me off guard sitting in traffic. Actually it happens while I'm slowing down in traffic and am about to come to a complete stop. It's happened twice, yesterday and I wanna say in September.

Jesus, while you were driving around for a while without the check valve, your motor coated everything in the intake path with oil. Until it's all taken apart and cleaned out, and the sensors are tested, its going to be really hard to pinpoint your problems. Also the BPV solenoid vac tap propably got drenched with oil, that may be a bad thing too. Its probably not as mucb of an issue if you bypassed the BPV solenoid, wouldnt hurt to check for oil in the BPV line.

 

[Llia]

Would oil in the BPV line be a sign of failed PCV then?

 

[mja]

Would oil in the BPV line be a sign of failed PCV then?

Not necessarily. The bpv solenoid* air bladder equilibrates with crankcase gas under low vac, the purpose of the red popper to the air bladder is just a check valve to fill up the bladder. It is normal to have some oil and crud in the crankcasw fumes in the gas. This could fill up the bladder over time and affect the BPV solenoid function. My writeup will give a fix for this also.

But if the orange PCV popper is gone, that bladder may fill with oil at a faster rate.

 

[JesusTheAgnostic]

Hmm, so should I take everything apart? Like everything that goes to the intake manifold?

 

[mja]

Your call, you run the risk of breaking a few things so be careful. Start with charge tubes/intercooler and work your way back, take out sensors and clean everything (tubes, intake, IC, tb, intake mani, etc) with hexane or isopropanol. Clean the sensors with their appropriate cleaners.

 

[JesusTheAgnostic]

I was actually planning on replacing the charge tubed and intercooler with MPFab's kit next, summer. I have actually noticed that occasionally my idle is irregular. Sometimes it's around 700, sometimes it's around 1000. So I think some stuff might be dirty. I know though that that stupid K&N intake is damaged, because that tube is apparently not at all sturdy so when you tighten it, it bends.

 

[mja]

I was actually planning on replacing the charge tubed and intercooler with MPFab's kit next, summer. I have actually noticed that occasionally my idle is irregular. Sometimes it's around 700, sometimes it's around 1000. So I think some stuff might be dirty. I know though that that stupid K&N intake is damaged, because that tube is apparently not at all sturdy so when you tighten it, it bends.

MPFab's kit is sick.

EPYON96R's car also had idle issues, the new intake manifold came with a new throttle body. The old LS motors throttle body's had an idle circuit in them, I haven't looked to closely at ours.

When you get oil spewing everywhere, it may gunk up the idle passage if we have one. Someone could confirm if we have an idle circuit in our TB.

 

[JesusTheAgnostic]

That's what I was thinking, I can't remember what the part is called though and haven't really had time to look it up. Something about idle air control or something like that.

 

[mja]

Ya I had an old junker sitting around.

Maybe this is your idle circuit?

If you want to take it apart to check it out, remove these screws with a T20 and drop out the throttle blade. I made a mistake of stripping one of the bolts, too old to be doing that kind of thing :blankface:

Pop out all these tabs:

And it should be held in with a set of gears inside, my guess is it should just slide out.

That one went in the trash instead of drilling out the screw. lazy.

 

[JesusTheAgnostic]

Well. I have two throttle bodies right, since the intake manifold comes with one. Which makes me wonder as to why it would be dirty since it's new.

 

[mja]

Maybe I misunderstood, did you used to have idle issues or still do?

 

[JesusTheAgnostic]

I do now. I dont remember having them before.

 

[mja]

That is odd. So you had the boost leak issue, then installed the new manifold/TB, and then had idle issues... anything else changed like tune?

Did the new manifold come with MAP sensor and injectors too?

 

[EPYON96R]

I do now. I dont remember having them before.

For my boost issue. (car ran fine under vacuum). I had boost leak and replacing the manifold fixed that because boost was leaking into the pcv system.

For my idle issue, I had okay idle until I tried to clean my maf sensor. After I cleaned it, it ran rough at idle. I switched mine with MJA to see if that fixed the idle and it did. So maybe switch yours with a known good maf sensor and see if that helps. also could be plugs or other things.

 

[JesusTheAgnostic]

Yeah, so basically it's not doing the thing where it just limits power, because I'm on a different tune. So that might be why, but it's still pretty irregular. I don't know where the MAP sensor is o: But yeah. new injectors, new throttle body. The whole deal. So basically if it's connected to the intake manifold then it's new.

 

[JesusTheAgnostic]

It doesn't really run rough. I mean it kinda shakes a little I think, but I might just be tripping. Traffic tends to make the car feel like it's shaking anyway.

 

[RMinNJ]

MAP sensor (??) or MAF sensor (where the air comes in). I'm getting confused but trying to follow the thread.

 

[EPYON96R]

I am not sure where the map sensor is. Maybe on the Intake Manifold? The MAF sensor, however, is located on the air filter intake tube that runs to the turbo.

 

[mja]

MAP sensor, on the top of the intake manifold. I believe it's a 3.3 bar (can read up to 48 psi - *1 atmosphere@15 psi = about 33 psi boost)

Not sure how these 'ECP' tunes work, could take some guesses.

To keep it simple, GM turbo cars use the MAF sensor upstream in relation to the bypass valve. At idle/low speed it'll read off MAF, under boost it'll incorporate MAP data. The MAF/MAP maps will overlap depending on engine conditions, so this is a rudimentary explanation.

Could try swapping MAF like EPYON96R said... but they're expensive :/