Preamble:
Upgraded clutch to Southbend when replacing leaky rear main seal.
Installed Cobb intake & CTS downpipe.
Tuned to Stage 2+ (preloaded Cobb tune map).
Driving happily for 2-3 weeks.... very happily
The issue:
Drove down to the shore (form north NJ - 1.5 hr drive) and got a MAF CEL on the way there. Car was drivable and parked with no issues overnight.
Went to drive home next day and car could barely hold an idle, revs dropped and stalled.
Could keep car alive by blipping the throttle, if letting the revs drop from the height of the blip, revs would drop straight to zero (hard stall).
Couldn't drive car, stalled under engine load.
Eventually tried disconnecting the MAF (after remembering CEL code) and the engine runs steadily/smoothly. As my daily driver, I must continue driving it for work and it drives smoothly with MAF disconnected.
My thoughts:
Initially thought bad MAF sensor: replaced it, no luck.
Initially thought change in engine feel was due to engine running in some kind of limp mode due to disconnected MAF... now convinced it is unmetered air in the intake.
Thinking engine feel change is lack of boost pressure making it to intake. Accelerating thru the range where you'd typically feel boost, I hear a ‘woosh’ that I’m fairly sure is not my new intake sound (assuming air leak).
I know I'm making about twice the boost now, so would understand a weak hose/connection/anything in the intake chain that gets pressurized by the turbo easily blowing.
What I’ve done so far:
Investigated all air flow channels from air filter to turbo, turbo to intercooler, and intercooler to intake manifold (and stupid noise generator) that are visible/reachable. Did so with minimal disassembly, so feeling around all pipes & molded plastic.
Ran the engine and listened for any leaks, had my dad rev the engine so I could listen for leaks.
Can anyone suggest any other locations to look for the leak or what other issues my symptoms could be?? I want my drivability back! TIA!
Upgraded clutch to Southbend when replacing leaky rear main seal.
Installed Cobb intake & CTS downpipe.
Tuned to Stage 2+ (preloaded Cobb tune map).
Driving happily for 2-3 weeks.... very happily
The issue:
Drove down to the shore (form north NJ - 1.5 hr drive) and got a MAF CEL on the way there. Car was drivable and parked with no issues overnight.
Went to drive home next day and car could barely hold an idle, revs dropped and stalled.
Could keep car alive by blipping the throttle, if letting the revs drop from the height of the blip, revs would drop straight to zero (hard stall).
Couldn't drive car, stalled under engine load.
Eventually tried disconnecting the MAF (after remembering CEL code) and the engine runs steadily/smoothly. As my daily driver, I must continue driving it for work and it drives smoothly with MAF disconnected.
My thoughts:
Initially thought bad MAF sensor: replaced it, no luck.
Initially thought change in engine feel was due to engine running in some kind of limp mode due to disconnected MAF... now convinced it is unmetered air in the intake.
Thinking engine feel change is lack of boost pressure making it to intake. Accelerating thru the range where you'd typically feel boost, I hear a ‘woosh’ that I’m fairly sure is not my new intake sound (assuming air leak).
I know I'm making about twice the boost now, so would understand a weak hose/connection/anything in the intake chain that gets pressurized by the turbo easily blowing.
What I’ve done so far:
Investigated all air flow channels from air filter to turbo, turbo to intercooler, and intercooler to intake manifold (and stupid noise generator) that are visible/reachable. Did so with minimal disassembly, so feeling around all pipes & molded plastic.
Ran the engine and listened for any leaks, had my dad rev the engine so I could listen for leaks.
Passenger side: I believe the accessory belt make a constant hiss as it runs around the pullies that had my attention for a bit.
Driver side: In front of bumper, I could easily hear my new intake sucking wind, but couldn’t confirm there wasn’t an additional sound from below (intercooler). Combined with the following, I’m concerned the intercooler end tank could be damaged, possibly around the mount it hangs on:
Driver side: In front of bumper, I could easily hear my new intake sucking wind, but couldn’t confirm there wasn’t an additional sound from below (intercooler). Combined with the following, I’m concerned the intercooler end tank could be damaged, possibly around the mount it hangs on:
*noticed that pushing up from the underside of the radiator/intercooler had a lot more flexibility/movement when pushing up from the driver side of it, rather than the passenger side. The driver side was basically sitting fully in the bushing at the bottom, while the passenger side seemed like it was supported from above somehow. Is this normal?
Can anyone suggest any other locations to look for the leak or what other issues my symptoms could be?? I want my drivability back! TIA!
