Topic: I have a noise when on boost with P0236; Won't start after filling the gas tank

[kennysabarese]

Ok so I popped that tube on the track, but everything was fine after I put it back. Drove home all good.

Went out to log a few days later. When slamming it, I got some noises that I'd heard before under full boost but they were pretty really loud.

Canned the logging event. Went on vacation

Came back from vacation, went out to log try to record audio of that noise because It's probably something loose, but I can't find anything loose. I've checked all my tbolts and other connectors.

Now I'm stuck in limp mode, not even one full boost pull, just putting down the street I could tell. In my past experiences with the car going into limp mode when first getting my tunes from Lyndon, it would run fine when I started it, I'd push it, it would go to limp, then I'd stop the engine, and when I start again it would be fine again. Not the case this time. I can't build more than 5PSI. No CEL but there is a code in HPT

"[ECM] P0236 -  (Pending) (Old) (Current) (Immature)"

Not sure what all the crap after means, it's kinda contradictory, but it stands for P0236 Turbocharger Boost System Performance.

Someone on another forum said they had a similar code and re-crimping the connectors to GMPP fixed it. But their limp mode was intermittent and my car has had GMPP for a lot of miles with no problems, so it's not my first guess.

I have a gut feeling something is leaking because of the noise, but I have no idea what the noise is, and I can't capture the noise now because I can't build boost when I drive the car! It's definitely sounding like some metal clanking but not hard like bang bang.

I figured I would do a boost leak test eventually, but it's easier to just have the car to it for me

Any ideas? The only pipes I haven't really touched are intercooler connections. I tried to inspect the IC but it's tough without taking the bumper off. Does a busted IC or loose IC connections make a unique noise?

Will clearing the code make the car get out of limp mode at least so I can attempt to get some boost to recreate the problem? I ran out of time tonight to try that

[Uranium-238]

First place I'd check would be the vacuum line-type lines that run to that one solenoid. on the driver's side of the engine.

What you really need to do is find some way to pressurize the system with an air compressor or something and listen for leaks.

[kennysabarese]

Didn't think about the little vacuum lines.

I got the boost test stuff ready to go. Just gotta do it.

[youtube]http://www.youtube.com/watch?v=fdjadhUP1u4[/youtube]

[Arabas]

is the noise coming from the turbo? could it be the wheel from the turbo?
there have been some cases where the turbo wheel died and of coursed caused some noise because the wheel was rubbing on the housing (sorry for the terms...do not know them- but i guess u can understand what i mean). one more thing to check if you heard noises, is the exhaust manifold. in some cases the screws come loose.

[kennysabarese]

i guess i won't know these things until i do the pressure test... though the pressure test doesn't test the exhaust manifold. i'll take a look into that one.

[Arabas]

i guess i won't know these things until i do the pressure test... though the pressure test doesn't test the exhaust manifold. i'll take a look into that one.

the top 4 screws are easy, the 4 on the down side are PITA (from what i've been told).
Pls be sure to check these screws, only after 24hrs the car is turned off and cooled down. otherwise, if the manifold is even slightly hot, it can be damaged .

[shabby]

Post a log when the car goes into limp mode.

[kennysabarese]

Pulled the car out of the garage, shut it down. 5 min later, cleared the code, then started it... when it dropped from the higher RPM idle to the lower RPM idle, it almost stalled.

so far idling in the driveway for a few minutes, no codes.

You can tell limp mode is gone just by revving it in neutral. revs climb much faster. in limp mode it's like the throttle never goes past 50 no matter how far you push it.

going to go make it break. and log it.

[kennysabarese]

Ok. got it to make the noise. recorded audio, it's distorted, but I think you'll get the idea.

Can't attach video to the post so here is a link to the video.

http://gallery.me.com/kennysabarese#100413/WTFNoiseFinal&bgcolor=black

Also took pics of the IC pipes. They are a little loose but I don't think so bad that they are leaking.

Going to do the pressure test Sunday.

[shabby]

May i suggest youtube for videos, don't feel like installing quicktime.

[kennysabarese]

Yeah I put it on youtube originally but it takes sometime to go public...

here you go

The "chuff" characteristic of the noise is just the distortion. It is not turbo surge.

EDIT: got a better recording of the noise on page 5

[shabby]

Inspect the bypass valve diaphragm and put the stock spring back in.

[HAMMER DOWN]

That's was the 1st thing that came to mind. That could make that flapping sound. Good luck.

Mike 

[kennysabarese]

Ok. Gotta find the stock spring!

[kennysabarese]

Ok got a [ECM] P2187 - System Too Lean at Idle Bank 1 (Old) (Current) (Immature)

WTF!!! is this related?

Gunna look at the turbo soon.

[shabby]

How do your fuel trims look?

[kennysabarese]

while driving around trying to duplicate the noise on friday:

LTFT -3.1% the whole time driving

STFT from 15% to -9%

I am using your config file so I see some of the histograms showing STFT and LTFT but not sure which one has the correct max and min.

My KR his really high as well. Sometimes hitting 10. Shit

[kennysabarese]

After driving home the car sat for two hours, went to start it up and it barely started.... It's never been that rough of a start before. Nothing close to that...

I know it's really hot outside. like 98 degrees and the car was sitting in the sun for 2 hours, but that was strange

Idling in the driveway right now LTFT and STFT are 0 and it's idling rough. It smoothes out and STFT is now hovering at around 22% then over the next two minutes decreasing and stabling around -1.6 to 0%

The P0236 comes up while the car is idling. I cleared it, and it came right back. When I clear it the STFT changes to flat, then, then climbs and the code happens. Right away. Scratch that. I think it was just stuck in the history. When I cleared codes It definitely changed the idle, but the code didn't come back again while idling for 5 minutes. So maybe stuck in the history or something? 

[kennysabarese]

Just did some reading that a P1287 can be caused by an exhaust leak. I did put in a catless DP lately.... When things cool down I'll check how tight things are at the turbo.

Also something about the purge valve (dunno what that is) and bad gas (too much ethanol)

http://www.solsticeforum.com/forum/f63/gmpp-tune-p0101-code-56557/index5.html#post880003

I am thinking this issue has nothing at all to do with the boost issue?

[kennysabarese]

One more thing to add to the pile of evidence. My Shift Light has been freaking out like crazy while driving lately, just randomly flashing all over the place. It's wired to the cylinder closest to the cabin. (cyl 4 I guess)

[Uranium-238]

Mine was doing that as well. I know I've got something haywire with the evap system, going to be getting that fixed soon.

I should point out that since my car came out of the shop I have NOT hooked the shift light back up, so if what the dealer did fixed it I wouldn't know.

[kennysabarese]

So your cylinder wire is still tapped but the light is not hooked up? Maybe I should cut the rev wire and cap it just to be sure?

[Uranium-238]

Yes, to disable the gauge in order to please the dealer I simply disconnected the ground wire.

[kennysabarese]

I guess i should disconnect power before cutting any wires. DUH.

[Uranium-238]

No no, I meant I disconnected the gauge's ground wire...honestly I don't think I remember to pull the battery cable first...