Strange noise on slight acceleration
A few months ago, i accidentally shifted into second at ~ 65mph - i realized what was going on right away and never fully engaged the clutch, nothing happened
out of paranoia i had a mechanic friend look at, listen to and drive the car a bit - i was worried about valvetrain damage - he told me it seemed fine to him, and damaged valves, bent or otherwise, are generally pretty noticable - he also said over-rev damage usually happens at pretty high engine speeds - in his expierence somewhere around 9K RPMs+, depending on the engine, im pretty sure when that happened i hit maybe like 7K rpms give or take
anyway the car seems fine - except for a very slight noise, in 4th gear @ about 1800 rpm's at say 30/35mph - just driving on residental streets
if i hold the car at that speed, nothing happens, but if i very gently push on the accelerator, say 1/4" i get a little bit of a "creeking" noise, thats the best way i can describe it - to me it sounds like an old wooden rocking chair creeking - it lasts for about a second before it either stops, or the intake drowns it out i cant exactly tell - its pretty quiet and i have to be listening for it
anyone have any ideas?
ive been reading up on it, but haven't found anything conclusive - i thought maybe wastegate flutter (not surge) - but it seems there is a lot of confusion and misinformation on both issues
the other thing that came to mind is possible the fuel pump? ive heard DI fuel pumps can make noise
or possibly the throttle plate moving every so slightly - or just normal noises that are audible now because of the intake (CS SRI + TIP) intercooler and/or Forge BPV
i cant hear it under any other conditions because of the wind, intake noises etc - and theres nothing else wrong with the car - it drives/responds exactly the same - idles fine, doesnt sound funny any other time
its been cold out too - lower 30's around here, any chance that impacts it at all?
also - i was thinking it might just be the actual gas pedal moving/making noise - but its definitley coming from inside the engine bay
thanks in advance for any insight
Last edited by CptMorgan; 03-28-2011 at 11:07 AM.
my car is tuned and i take the car to 7k when i shift at the strip and it holds just fine, and the cars can handle 7500 rpms i just prefer to leave a little breathing room so i doubt you've got any engine damage. i know the motor mounts on our cars are pretty soft, perhaps the sudden jerk when the revs shot up knocked something loose? maybe its just a line or something that popped out of its hanger.
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I'm getting the same exact sound except my sound is constant. Happens all of the time. No solution yet.
Then - 2010 MZ3S 5-door - RIP 2/18/11, ty for keeping me alive.
Now - 2011 Mazdaspeed 3, Tech Package
I just installed the CS SRI+TP and I'm getting a similar noise now. Mainly on partial throttle at lower RPM, say light throttle in 3rd or 4th while cruising.
^ Do what the previous poster said. Check your mounts as well as your silicone hoses (rubbing against something under throttle.
2007 CBM Mazdaspeed 3
CP-e TMIC / COBB SF intake / COBB AP / COBB TIP / SU boost tubes / JBR SSP / CP-e RMM / TRZ tranny mount / TXS Catback / CS Airbox / ITV-22's / SURE phenolics / Tuned by COBB Plano / CS TestPipe / COBB RSB / AWR rear endlinks / Redline hood struts / COBB knob / Enkei FLC-01's / BFG KDW2 235.40.18 / JBR EGR delete /
|acceleration, flutter, noise, slight, strange|