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man show 04-06-2012 07:54 PM

Occasional boost = dying turbo?
I'm wondering if my turbo might finally be on its last legs. My car currently has 92k on it and everything in my profile is up to date.

In 1st, 2nd, and usually 3rd gear, my car drives like it should - there's plenty of power and nothing feels or sounds unusual. In those gears, both my Prosport Electric boost gauge and my Cobb AccessPORT read boost in the high teens (psi), but in 4th and 5th gear, it feels like I have no power beyond what the engine produces and the boost reads between 0 and 5 psi (+/-) with the gas pedal held to the floor if I'm lucky.

I've visually checked all the connections that I can see in the engine and everything looks ok. I've also listened for any leaks and I didn't hear anything obvious. I reset my ecu with my AP and the same exact symptoms are present. I didn't see any smoke coming from the exhaust, the car doesn't consume an unusual amount of oil, and I didn't smell any unusual smells.

Honestly, I'm just about at the limit of my diagnosis abilities.

Part of me is hoping it's the turbo so I can upgrade that (and I'm not sure exactly what to get yet), but part of me is hoping it might be a simple fix. Anybody have any ideas what it could be based on my description of the symptoms?

bad grocerygetter 04-06-2012 08:49 PM

No cel i assume? Kinda strange. Those two gears should show the highest boost. If not the turbo maybe something in the ecu being stupid? Does it happen at any speed? Or only higher speeds(where one would expect to be using those gears). In other words will it build boost from lower rpm? Say 40mph in 4th up to higher rpm
Not exactly sure where I'm going with that, except maybe something other than turbo. Just seems strange for the turbo to work in some gears and not others. hopefully we can get you helped out.

man show 04-06-2012 09:25 PM

Nope, no CELs and no codes read on the AP.

When the car is in 4th or 5th gear at almost any speed, it won't build boost. It's the weirdest thing. I'll take another look under the hood tomorrow morning and make sure everything's connected like it should be, but if I had a loose connection, I'd expect to not be able to build and hold boost in every gear, not just 4th and 5th.

BLAZE2099 04-06-2012 09:41 PM

I just searched it on Google. and found multiple things leading to it.

To be honest John, It happens to me quite a bit as well...just kinda figured it was cut/or over boosting at the top of fourth resulting in my shitty 5th.

bad grocerygetter 04-06-2012 11:02 PM

Possibly something wrong with the 3port bcs? I don't have a lot of knowledge with them but it seems possible. Is the exhaust you have catless? If not you may Check the cat. That one seems weak to me though because that would effect all gears.

man show 04-07-2012 07:16 AM

My Cobb downpipe has a high flow catalytic converter. It's been on for 4 years, 2 months and almost exactly 80,000 miles. I don't imagine that's the cause, but you never know.

I think I read that you can clean the 3 port with a little bit of electric cleaner, but I just had it installed and had the car tuned for it <10k ago. I don't imagine it got dirty or went bad so fast, but it could have.

To compound the problem, I also noticed some very recent [I]overboosting[/I] like to the low 20's, so maybe that triggered something that's limiting my top end power? But even with the ecu reset, the power is still absent.

Almost 0 boost in 4th and 5th gear, but seemingly full power in 1st-3rd. I'm so puzzled :confused:

turmic 04-07-2012 03:41 PM

That is a odd one. Because even 3rd will give you full spool. If you want...I can ask my tuner and see what he thinks.

This? John are your spark plugs clean? I know those crap plugs you put on the one time gave you some trouble.

pzr2874 04-07-2012 08:58 PM

Your firmware UTD?

Post a log of a 3rd and 4th gear pull. There will be a difference, one of these yahoo's will see it.

Wouldn't hurt.

man show 04-07-2012 10:42 PM

Thanks Kirt, I actually just read that thread before opening this one again. My plugs should be in good shape - I put in a set of NGK Iridiums (stock heat level) at 60k and gapped them all to 0.030".

Yep Paul, my AP firmware is up to date - at least it was several months ago when I got tuned.

The same exact symptoms as yesterday happened today on my way to work: partial boost in 1-3, very little to none in 4-5. Once I got to work, I had no boost in any gear. After work, when I turned on my car and let it idle in the parking lot, I heard a faint metal-on-metal sound, kind of like a heat shield vibration, and I followed the sound and it turns out the wastegate actuator arm is actually contacting my Cobb turbo heatshield again. I had that same problem before: [url][/url]

After I fixed it the first time, there was enough clearance to almost fit my pinky finger between the arm and the heat shield, but now they're almost contacting eachother again. I have a feeling the wastegate arm might have come detatched or something, so I'll try pulling the turbo heat shield off tomorrow morning and see if that's the case. I would imagine not having a properly working wastegate would cause some strange boost readings and then none at all if it's stuck open or closed or just floating.

Another problem arose today too: my car no longer chirps when I hit the lock button on my key fob. I have a feeling I might have a weak connection to one of my horns. That one should hopefully be easy to figure out.

pzr2874 04-07-2012 10:57 PM

Buy a new td. 90+K.... screw it.

man show 04-08-2012 07:38 AM

That's what I'm thinking... I'm about to take a look at it right now.

On a side note, I see you finally got yourself an avatar - nice :)

bad grocerygetter 04-08-2012 10:23 AM

Do you have the stock alarm key fob? If so it tells you how to silence the horn chirp on the back of it. And how to turn it back on. Check that.

man show 04-08-2012 11:53 PM

Thanks, the only instructions I saw on the back of the fob were how to start and stop the car finder function. I did find some instructions online about how to mute/unmute the chirp, so I'll give that a try tomorrow.

I was still unsuccessful at finding a cure to my lack of boost. I think I'm going to hand this one over to the professionals. I shot emails to IAG, Andrewtech, and Element, so we'll see which one can get me in first.

turmic 04-09-2012 09:58 PM

Let us know what you end up finding....or they end up finding.

pzr2874 04-10-2012 05:50 AM

Earlier someone posted about the 3 port. I remember vaguely that GS is sending out replacements from past shipments. Might be worth looking into.

Good luck

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