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12-15-2017, 08:50 AM | #1 |
Scooby Newbie
Member#: 477013
Join Date: Nov 2017
Location: Massachusetts
Vehicle:2019 STI Limited Ice Silver Metallic |
2018 loud on start up
Hey guys just bought a new 2018 wrx premium with the 6speed manual back in September . Just wondering why on start up the engine sounds very loud almost like theres no oil in it for about 10 seconds then goes away. The noise is also heard in the exhaust. Not sure if this is done on purpose for an agressive tone at start up. Anyone know if this is normal? Also while in gear, 4th gear is the only one i feel vibration in the shifter. Thanks for the help
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12-15-2017, 09:18 AM | #2 | |
Scooby Newbie
Member#: 411992
Join Date: Jan 2015
Chapter/Region:
Tri-State
Vehicle:2018 WRX STi ISM |
Quote:
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12-15-2017, 11:50 AM | #3 |
Scooby Newbie
Member#: 461037
Join Date: Jan 2017
Chapter/Region:
SCIC
Location: SoCal
Vehicle:2016 Subaru World Rally Blue |
You are describing the cold start cycle. As said above it idles higher and the result is a louder and more aggressive sound from the exhaust. Completely normal. I have the 4th gear vibration too sometimes and I am pretty sure it’s normal. I don’t think any manual car ever made has zero vibration in the shifter.
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12-15-2017, 12:02 PM | #4 |
Scooby Newbie
Member#: 452695
Join Date: Aug 2016
Chapter/Region:
BAIC
Location: San Francisco, CA
Vehicle:2017 WRX Limited DGM |
everything you mentioned is normal
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12-16-2017, 07:16 AM | #5 |
Scooby Specialist
Member#: 283429
Join Date: May 2011
Chapter/Region:
South East
Location: Down yonder.
Vehicle:2016 Fuji Sunfire 03 Silver |
Yup, perfectly normal - just one of the "fun" things engineers can do with direct injection...
The actual purpose as mentioned is to heat the cat up faster. The ECM is injecting fuel late in the compression cycle which then finishes burning in the exhaust after the exhaust valves open. |
12-16-2017, 09:07 PM | #6 |
Scooby Newbie
Member#: 477013
Join Date: Nov 2017
Location: Massachusetts
Vehicle:2019 STI Limited Ice Silver Metallic |
Thanks for the info guys it all makes sense.
Is it also normal to hear some slight clanking noises from the front suspension when hitting bumps? almost sounds like bad strut mounts that i used to have in an older car. But I'm sure this is something normal due to the sport riding nature of this car. Thanks again |
12-16-2017, 09:16 PM | #7 |
Scooby Newbie
Member#: 465695
Join Date: Apr 2017
Chapter/Region:
MAIC
Location: Lancaster, PA
Vehicle:2017 WRX Premium Black Silica |
It's pretty normal for a cold startup.
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12-18-2017, 09:45 AM | #8 | |
Scooby Newbie
Member#: 461037
Join Date: Jan 2017
Chapter/Region:
SCIC
Location: SoCal
Vehicle:2016 Subaru World Rally Blue |
Quote:
Do you have a video? |
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12-18-2017, 09:09 PM | #9 | |
Scooby Newbie
Member#: 465423
Join Date: Apr 2017
Location: Chicago, IL
Vehicle:2018 WRX Premium DGM |
Quote:
THIS...I also feel vibration after shifting to fourth. And NO I am not resting my hand on the shifter. It can be felt immediately after shifting into 4th! Thought there was something wrong with mine. |
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12-19-2017, 03:55 AM | #10 |
Scooby Newbie
Member#: 219009
Join Date: Jul 2009
Chapter/Region:
Tri-State
Location: NJ
Vehicle:2018 LBP WRX Ltd. 2005 PSM WRX - St.2 (rip) |
it will always be loud on a cold startup. kind of standard for wrxs. enjoy the car.
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12-21-2017, 03:25 PM | #11 |
Scooby Specialist
Member#: 472037
Join Date: Jul 2017
Chapter/Region:
MWSOC
Vehicle:2018 WRX Limited CWP |
It's loud also there is an air pump that's pumping fresh air into the exhaust to heat up the cat. It's pretty normal. Some cars sound like a vacuum when you start it.
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12-23-2017, 07:51 PM | #12 |
Scooby Newbie
Member#: 167150
Join Date: Dec 2007
Location: Palatine, Illinois
Vehicle:2006 WRX OBP |
put me in for 4th gear shifter vibrations...
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12-24-2017, 09:26 AM | #13 | |
Scooby Specialist
Member#: 283429
Join Date: May 2011
Chapter/Region:
South East
Location: Down yonder.
Vehicle:2016 Fuji Sunfire 03 Silver |
Quote:
There is no secondary air pump on 2018 WRX. Nor 2017, 2016, 2015... Last edited by Elbert Bass; 12-25-2017 at 10:21 AM. |
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12-25-2017, 06:25 PM | #14 |
Scooby Newbie
Member#: 422693
Join Date: Jun 2015
Chapter/Region:
Tri-State
Location: Buffalo,NY
Vehicle:2016 WRX Premium Lapis Blue Pearl |
I believe the loudness is the ignition timing retard that is on the OTS tunes to heat the cat up. I have an etune and noticed that my car no longer does this, but still have close to 2k rpm idle on a cold start. Have a catted grimmspeed jpipe.
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12-26-2017, 10:29 AM | #15 |
Scooby Specialist
Member#: 283429
Join Date: May 2011
Chapter/Region:
South East
Location: Down yonder.
Vehicle:2016 Fuji Sunfire 03 Silver |
Nope, it's injection timing. Subaru calls it "Stratified Mode". It injects a lean pulse of fuel on the intake stroke and then a rich pulse during compression. The result is the fuel/air mixture is still burning as the exhaust valves open creating that noise.
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12-27-2017, 08:07 PM | #16 |
Scooby Newbie
Member#: 468884
Join Date: Jun 2017
Chapter/Region:
MWSOC
Location: Elkhart
Vehicle:2008 Impreza WRX STi Aspen White |
Mine drones until it settles @ 850
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12-27-2017, 08:42 PM | #17 |
Scooby Specialist
Member#: 472037
Join Date: Jul 2017
Chapter/Region:
MWSOC
Vehicle:2018 WRX Limited CWP |
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12-27-2017, 08:49 PM | #18 |
Scooby Newbie
Member#: 471388
Join Date: Jul 2017
Location: Omaha/Council bluffs
Vehicle:2017 WRX black |
sounds like a normal cold start to me.
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12-28-2017, 06:38 AM | #19 | |
Scooby Guru
Member#: 428511
Join Date: Aug 2015
Location: philadelphia
Vehicle:2016 STI |
Quote:
My STI sounds the same way due to ultra retarded timing when cold. I'm pretty sure my STI isn't injecting a rich pulse during the compression stroke considering the intake valve is closed. The spark timing is what affects 'when' the majority of the burn takes place. |
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12-28-2017, 07:18 AM | #20 | |
Scooby Specialist
Member#: 283429
Join Date: May 2011
Chapter/Region:
South East
Location: Down yonder.
Vehicle:2016 Fuji Sunfire 03 Silver |
Quote:
Since 2015 WRX has had an FA20 with Direct injection Turbo and it can (and does) inject fuel at different times and multiple times during intake and compression strokes depending on conditions. |
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12-28-2017, 08:25 AM | #21 | |
Scooby Guru
Member#: 428511
Join Date: Aug 2015
Location: philadelphia
Vehicle:2016 STI |
Quote:
The louder, deeper, later ignition timing exhaust sound on cold start ups is from a later ignition timing. That's why it's the same louder, deeper, later ignition timing sound in my STI. |
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12-28-2017, 04:31 PM | #22 | |
Scooby Specialist
Member#: 372777
Join Date: Nov 2013
Chapter/Region:
SCIC
Location: Compton, CA
Vehicle:2014 WRX Sedan Lmtd WRB |
Quote:
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12-30-2017, 07:47 AM | #23 | |
Scooby Specialist
Member#: 283429
Join Date: May 2011
Chapter/Region:
South East
Location: Down yonder.
Vehicle:2016 Fuji Sunfire 03 Silver |
Quote:
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12-31-2017, 05:40 PM | #24 | |
Scooby Guru
Member#: 428511
Join Date: Aug 2015
Location: philadelphia
Vehicle:2016 STI |
Quote:
are you serious man? What am I missing about cold start operation? serious question too. why is my sti no different if it's the direct injection fundamentals causing this? |
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