(For the short, but boring version, skip to 'quick overview' below, lol....)
Oh my goodness... Well I hope there are a few of you who enjoy a good novel, since I chose to attack the problems with this car in succession (for the most part) as opposed to posting every individual issue. I've dug through CT and guessed as to the on-going vacuum/turbo problem and the end result to date has been to throw time and parts and time at the problem. Here's what I've done, discovered, and where I'm at. I know I'm far from the only one with these issues; most of us have had at least one, so maybe this will help narrow down problems for others. Think of it as an expensive timeline of 'What the H*ll Could it Be'??!?
Background: Bought the car used, bone stock, no major issues (only small ones unrelated to this post). Currently 112k miles on the car. Added AEM intake.
1.) Sooo, 25k miles or so into owning the car I started having 'bucking' issues, where it feels like the boost would bounce around and not provide consistent boost. CT search suggested checking the little check valve on the valve cover. Sure enough, plug the hole, car goes crazy.
- Result: Purchased and installed and it ran fine again.
2.) Well now I got a little turbo beasty in the making, right?!?! After much research I went the high $$$ route in terms of tuning and got a BNR tuner and 3 tunes. Installed the 1st (hi perf tune 91) and tried it out. Wow what a difference. Switched to the 2nd tune (eco) and the car wouldn't start, only crank. OK, back to the 1st. Never tried the 3rd (hi perf 87) and just went about the next few days having fun with the car. After I get back into the tune stuff I'll be glad to write more about my experience with BNR.
- Result: My boring-a$$ fuel-sipping daily driver is pretty darn fun now. My brother wants to buy it off me!
3.) A week after the tune the car flipped out. Wouldn't start, at least not without holding down the key and gas and keeping it to the floor to get some amount of boost. Anything passed 1/4 pedal it'd go bat crap crazy (mechanic jargon, sorry for the specialist speak). Happened at several inopportune times and got stranded. So she was parked for a month while I diligently searched through CT and online. My conclusion is it must be the intake manifold PCV, so I patiently awaited my PCV fix V2 [from XtremeRevolution] that I found here on CT.
- Result: Bummed and gave up on the car for awhile. Tracing down these weird random symptoms has taken weeks, and it sucks right?!?!
4.) Let's remove an Intake! Using [XtremeRevolution] instructions on CT, I took my sweet time and went step by step removing sensors, fuel rail, etc etc until I could get to the manifold. Ooops! Broke off the nipple from the bypass sensor (see one of my previous posts), but got the darn thing off after an hour. Rain and my lack of enthusiasm delays the V2 fix. I finally get around to it, take my time on the install, which went fairly cleanly. Only real 'issue' I had was it seemed I couldn't get the regulator elbow very tight. I ground down the nut on several sides to slowly get it tighter, but whatever, it went in, I didn't feel 'great' about that, but it seemed to seal ok. Glued the broken nipple back on and threw it all back together. Test drove it a couple miles down the street and the CEL lit and got all kinds of errors, yay. Limped it back home and bought a brand new intake manifold.
- Result: At this point I felt like there were a LOT of variables being introduced here: Intake that might still be leaking, BNR custom tune still on the car, bypass nipple may not have sealed properly, that stupid thin hard line to the bypass sensor seemed to not want to seat in super tight. Sometimes the bypass would 'phss phss phss' instead of holding boost. Other times I'd seat it, it'd hold boost, then stammer at mid-hard acceleration.
5.) New GM intake manifold installed. This time 15 minutes for removal, 10 minutes to swap TB, sensors, and clamp holders, and 15 minutes to install. At least I'm a pro at this now and can do it from memory!!!
- Result: Woot! The car ran like it did right after the BNR tune. After 3 miles of testing I came home and told the wife it's finally fixed and she gets her husband back. (Well, except for the '88 Stang project, but that's a different story....)
6.) Drove it to work the next day, started bucking and stammering up a modest hill at 1/2 throttle. By the time I got home it was back to not starting (without holding down the gas and keeping on it to build boost again) and forget rolling the throttle into mid range or higher rpm's. Essentially the car exhibits the same issues as when I started troubleshooting this mess.
- Result: WTF is the problem!?! I'm out of ideas at this point!!!
7.) Back to basics.... As of today, I've decided to do the following: a.) Drive to work in an iffy car because I have to. Still no CEL after the manifold replacement, but no question something is wrong. b.) checked the bypass valve hard vacuum line, all seems good. c.) post here to see if the fine folks on CT have any ideas. d.) When I get home I'll load my stock tune and start from there. The fewer variables the better. I'll also check for passive CEL codes since I'll have 100 miles on it by then.
Phew, So there you have it folks... A few hundred dollars, hours of research, and more hours under the hood and the car seems to be no different than when I started, lol.
Any thoughts would be greatly appreciated!!! (Aside from sell her, she's obviously possessed.)
:: Quick Overview ::
- 2012 Cruze, AEM intake, BNR tune, otherwise stock 112k miles
- New intake and camshaft cover to address vacuum issues. No go, see below
- Won't start without holding down key and accelerator and keeping on it until vacuum builds.
- Occasionally dies at idle/stand still
- Once running, it's *fine* unless I give it a fair amount of gas, at least enough to get the turbo passed a few pounds, then it jerks and bucks horribly.
- Accelerating from idle takes a super long time to build up boost or it'll fall on it's face
Good times!
-DD
Oh my goodness... Well I hope there are a few of you who enjoy a good novel, since I chose to attack the problems with this car in succession (for the most part) as opposed to posting every individual issue. I've dug through CT and guessed as to the on-going vacuum/turbo problem and the end result to date has been to throw time and parts and time at the problem. Here's what I've done, discovered, and where I'm at. I know I'm far from the only one with these issues; most of us have had at least one, so maybe this will help narrow down problems for others. Think of it as an expensive timeline of 'What the H*ll Could it Be'??!?
Background: Bought the car used, bone stock, no major issues (only small ones unrelated to this post). Currently 112k miles on the car. Added AEM intake.
1.) Sooo, 25k miles or so into owning the car I started having 'bucking' issues, where it feels like the boost would bounce around and not provide consistent boost. CT search suggested checking the little check valve on the valve cover. Sure enough, plug the hole, car goes crazy.
- Result: Purchased and installed and it ran fine again.
2.) Well now I got a little turbo beasty in the making, right?!?! After much research I went the high $$$ route in terms of tuning and got a BNR tuner and 3 tunes. Installed the 1st (hi perf tune 91) and tried it out. Wow what a difference. Switched to the 2nd tune (eco) and the car wouldn't start, only crank. OK, back to the 1st. Never tried the 3rd (hi perf 87) and just went about the next few days having fun with the car. After I get back into the tune stuff I'll be glad to write more about my experience with BNR.
- Result: My boring-a$$ fuel-sipping daily driver is pretty darn fun now. My brother wants to buy it off me!
3.) A week after the tune the car flipped out. Wouldn't start, at least not without holding down the key and gas and keeping it to the floor to get some amount of boost. Anything passed 1/4 pedal it'd go bat crap crazy (mechanic jargon, sorry for the specialist speak). Happened at several inopportune times and got stranded. So she was parked for a month while I diligently searched through CT and online. My conclusion is it must be the intake manifold PCV, so I patiently awaited my PCV fix V2 [from XtremeRevolution] that I found here on CT.
- Result: Bummed and gave up on the car for awhile. Tracing down these weird random symptoms has taken weeks, and it sucks right?!?!
4.) Let's remove an Intake! Using [XtremeRevolution] instructions on CT, I took my sweet time and went step by step removing sensors, fuel rail, etc etc until I could get to the manifold. Ooops! Broke off the nipple from the bypass sensor (see one of my previous posts), but got the darn thing off after an hour. Rain and my lack of enthusiasm delays the V2 fix. I finally get around to it, take my time on the install, which went fairly cleanly. Only real 'issue' I had was it seemed I couldn't get the regulator elbow very tight. I ground down the nut on several sides to slowly get it tighter, but whatever, it went in, I didn't feel 'great' about that, but it seemed to seal ok. Glued the broken nipple back on and threw it all back together. Test drove it a couple miles down the street and the CEL lit and got all kinds of errors, yay. Limped it back home and bought a brand new intake manifold.
- Result: At this point I felt like there were a LOT of variables being introduced here: Intake that might still be leaking, BNR custom tune still on the car, bypass nipple may not have sealed properly, that stupid thin hard line to the bypass sensor seemed to not want to seat in super tight. Sometimes the bypass would 'phss phss phss' instead of holding boost. Other times I'd seat it, it'd hold boost, then stammer at mid-hard acceleration.
5.) New GM intake manifold installed. This time 15 minutes for removal, 10 minutes to swap TB, sensors, and clamp holders, and 15 minutes to install. At least I'm a pro at this now and can do it from memory!!!
- Result: Woot! The car ran like it did right after the BNR tune. After 3 miles of testing I came home and told the wife it's finally fixed and she gets her husband back. (Well, except for the '88 Stang project, but that's a different story....)
6.) Drove it to work the next day, started bucking and stammering up a modest hill at 1/2 throttle. By the time I got home it was back to not starting (without holding down the gas and keeping on it to build boost again) and forget rolling the throttle into mid range or higher rpm's. Essentially the car exhibits the same issues as when I started troubleshooting this mess.
- Result: WTF is the problem!?! I'm out of ideas at this point!!!
7.) Back to basics.... As of today, I've decided to do the following: a.) Drive to work in an iffy car because I have to. Still no CEL after the manifold replacement, but no question something is wrong. b.) checked the bypass valve hard vacuum line, all seems good. c.) post here to see if the fine folks on CT have any ideas. d.) When I get home I'll load my stock tune and start from there. The fewer variables the better. I'll also check for passive CEL codes since I'll have 100 miles on it by then.
Phew, So there you have it folks... A few hundred dollars, hours of research, and more hours under the hood and the car seems to be no different than when I started, lol.
Any thoughts would be greatly appreciated!!! (Aside from sell her, she's obviously possessed.)
:: Quick Overview ::
- 2012 Cruze, AEM intake, BNR tune, otherwise stock 112k miles
- New intake and camshaft cover to address vacuum issues. No go, see below
- Won't start without holding down key and accelerator and keeping on it until vacuum builds.
- Occasionally dies at idle/stand still
- Once running, it's *fine* unless I give it a fair amount of gas, at least enough to get the turbo passed a few pounds, then it jerks and bucks horribly.
- Accelerating from idle takes a super long time to build up boost or it'll fall on it's face
Good times!
-DD