Engine revvs up on cold start

D_o_S · 01-27-2012, 02:35 PM

Hi guys,

I've noticed that the engine revvs up after a cold start, to approx 1100 rpm, and decreases slowly, after about a minute its at 650 rpm, and the exhaust flap opens.

If I add gas, the procedure interrupts and the engine settles down to 650 rpm.

The car has always been like this. What is this feature for?

Thanks.

MKR_DmD · 01-27-2012, 02:53 PM

Completly normal. Just helps the car warm up faster.

Syndicategt · 01-27-2012, 02:57 PM

Quote:

Originally Posted by DrivinMissDaisy

Completly normal. Just helps the car warm up faster.

+1 As long as the RPM's are not rapidly bouncing you are good.

Beemw335 · 01-27-2012, 03:07 PM

lol,
yup normal, every car does this, helps engine warm up.

BES335xi · 01-27-2012, 03:07 PM

Yeah mine does the same thing, asked a few mechanics or whatnot, and they all told me it's completely normal and like these guys said above me, as long as it's not jumping around, it's all good..

NiVeDh · 01-27-2012, 03:08 PM

Normal. It brings oil pressure up and heats up the cats.

smack · 01-27-2012, 11:00 PM

Every car does it. My commuter jumps up to 1800 and stays there for a little while then slowly comes down to normal idle. Just takes a bit longer to get where it needs to be than the BMW. Of course the Toyota sits outside over night while the BMW is in the garage.

D_o_S · 01-28-2012, 04:07 AM

Thanks, so is this a performance feature (warm up of engine) or a emissions feature (cats) OR neither or both?

X2Board · 01-28-2012, 06:45 AM

Quote:

Originally Posted by D_o_S

Thanks, so is this a performance feature (warm up of engine) or a emissions feature (cats) OR neither or both?

Primarily emissions. A hot cat works more efficiently than a cold cat.

**335i** · 01-28-2012, 07:20 AM

i noticed that sometimes when u stand in a trafic its bounc to 750 rpm from 650 or so, and stays in one postition not rapidly bouncing

01-27-2012, 02:35 PM	#1
D_o_S LCI'd 257 Rep 819 Posts Drives: 335i LCI Join Date: Feb 2008 Location: Home iTrader: (1)	Engine revvs up on cold start Hi guys, I've noticed that the engine revvs up after a cold start, to approx 1100 rpm, and decreases slowly, after about a minute its at 650 rpm, and the exhaust flap opens. If I add gas, the procedure interrupts and the engine settles down to 650 rpm. The car has always been like this. What is this feature for? Thanks.
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01-27-2012, 02:53 PM	#2
MKR_DmD Lieutenant 6 Rep 494 Posts Drives: 16 Jeep Cherokee Join Date: May 2010 Location: Germany iTrader: (3)	Completly normal. Just helps the car warm up faster.
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01-27-2012, 03:07 PM	#4
Beemw335 Colonel 62 Rep 2,013 Posts Drives: 335i Join Date: Mar 2011 Location: My car is my home iTrader: (2)	lol, yup normal, every car does this, helps engine warm up.
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01-27-2012, 03:07 PM	#5
BES335xi Colonel 83 Rep 2,132 Posts Drives: FBO+ N54xi Join Date: Mar 2008 Location: Queens, NYC iTrader: (4) Garage List 03/07 E90 335xi [1.00]	Yeah mine does the same thing, asked a few mechanics or whatnot, and they all told me it's completely normal and like these guys said above me, as long as it's not jumping around, it's all good.. __________________ JB4+usb \| P3 Vent Boost Gauge v2 \| BMS OCC \| BMS DCI \| AMS FMIC \| AR xi CL DP's \| BT Tool \| Edibias/NCSExpert/INPA BMW Coding \| Cyba Quad Exhaust tips \| M-Tech Rear & M3 Front Bumper \| Red Cyba Air Scoops \| Blacklines \| Vinyl Overlays \| ACS Roof Spoiler \| Matte Black Grilles \| LED Side Mirrors \| Rear Euro Fogs \| etc.. .
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01-27-2012, 03:08 PM	#6
NiVeDh Major General 422 Rep 8,003 Posts Drives: '08 E90 335i, '99 E36 M3 Join Date: Apr 2009 Location: Houston, TX & Atlanta, GA iTrader: (132) Garage List 2008 BMW 335i Sedan [8.66]	Normal. It brings oil pressure up and heats up the cats.
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01-27-2012, 11:00 PM	#7
smack Lieutenant Colonel 34 Rep 1,569 Posts Drives: BMW's/Flex Polishers Join Date: Apr 2007 Location: Spangdahlem Germany iTrader: (0)	Every car does it. My commuter jumps up to 1800 and stays there for a little while then slowly comes down to normal idle. Just takes a bit longer to get where it needs to be than the BMW. Of course the Toyota sits outside over night while the BMW is in the garage.
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01-28-2012, 04:07 AM	#8
D_o_S LCI'd 257 Rep 819 Posts Drives: 335i LCI Join Date: Feb 2008 Location: Home iTrader: (1)	Thanks, so is this a performance feature (warm up of engine) or a emissions feature (cats) OR neither or both?
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01-28-2012, 07:20 AM	#10
335i Colonel 184 Rep 2,320 Posts Drives: TOYOTA & 2008 E92 335i 6MT Join Date: Jul 2007 Location: Swiss iTrader: (4) Garage List 2008 335i [9.00]	i noticed that sometimes when u stand in a trafic its bounc to 750 rpm from 650 or so, and stays in one postition not rapidly bouncing __________________ E92 335i Black Saphire 6MT PROcede V5, BMS DCI, Big Tom IC, AR CL-DP's 3", AR Design OC, Forge DV's, OEM M3 side skirts, BMW Performance Wheels 19 inch 269 Black Gloss+Continental ContiSportContact 5P (400hp and 550nm) https://www.youtube.com/user/aistis7..._as=subscriber
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