Cold weather and check tire lights - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)

ric80 · 01-25-2013, 07:15 PM

Hi All-- So the temperature drops and I get a big warning that all my tires need air, I shouldn't drive over 50F, etc...

Whats up-- is this normal?

08LMB135i · 01-25-2013, 07:24 PM

Pressures will drop with low temperatures, try upping your pressures just a bit.

ric80 · 01-25-2013, 07:26 PM

I sort of get that-- but why are these things triggered so sensitively? Does anybody else see this?

ShocknAwe · 01-25-2013, 07:26 PM

Cold air is denser, molecules slow down blah blah. Essentially warm air higher pressure, cold air lower pressure. Add more air if it's going to be cold for a while, try to keep it around specs. Your tire pressure rises a little when driving after the rubber heats up too.

If you added warm air, the molecules were spaced out more, when it got cold, they crammed in closer. The colder it gets the lower the pressure goes and the TPMS I believe sense a 10% reduction, which isn't much.

mryakanisachoad · 01-25-2013, 07:32 PM

Normal

ric80 · 01-25-2013, 07:45 PM

You guys all get warnings when it gets cold? I think it is strange.

rking117 · 01-25-2013, 08:35 PM

yes it is likely to happen more when it is cold. Think about it when most things get cold they shrink. same thing happens to the air molecules. When this happens tire pressure goes down. It is easy to see a fluxuation of a few PSI with as little of a variance of 10 or more degress.

Suprgnat · 01-25-2013, 08:57 PM

PV=nRT

http://en.wikipedia.org/wiki/Ideal_gas_law

Sylon · 01-25-2013, 10:16 PM

Quote:

Originally Posted by ShocknAwe

Cold air is denser, molecules slow down blah blah. Essentially warm air higher pressure, cold air lower pressure. Add more air if it's going to be cold for a while, try to keep it around specs. Your tire pressure rises a little when driving after the rubber heats up too.

If you added warm air, the molecules were spaced out more, when it got cold, they crammed in closer. The colder it gets the lower the pressure goes and the TPMS I believe sense a 10% reduction, which isn't much.

Hit it right on the head. Completely normal.

Although my tires are filled with nitrogen, so I'm not expecting to see these low pressure warnings. But we'll see.

rking117 · 01-25-2013, 11:47 PM

nitrogen also expands and contracts. you will see the warning but it might take longer. The gas is more dense if i remember right. Sylon I dont think i could do without you here to keep me straight. Oh and everytime i see your icon I think Girl 1er = cool then only to realize its just Sylon.

RimasRS · 01-26-2013, 03:42 AM

1st I hate TPMS
2nd I have those warning lights when it is cold. But I've read somewhere that it is normal to see warnings when weather gets colder because TPMS sensors measures the temp also when it changes dramatically they give you warning light "check pressure in your tires then reset"

Dackelone · 01-26-2013, 05:34 AM

The TPMS is a "dumb" system. Meaning... when its 80'F out and you set the TPMS target pressure... and then the temp drops.... the TPMS is still looking for that higher (tire)pressure, hence the light come on.

When ever you check your tire pressure... you should ALSO reset the TPMS so it knowns the new "target" pressure. You should be checking your tire pressure every third fill up anyways. But see the problem no one does, and Congress stuck us with this crappy TPMS.

RimasRS · 01-26-2013, 05:39 AM

The funny thing is that I had maybe 100 times warning light and non of them showed the real problem.

I am really thinking to code out that system and activate European TPMS which is w/o stupid sensors

Dackelone · 01-26-2013, 05:52 AM

Quote:

Originally Posted by RimasRS

I am really thinking to code out that system and activate European TPMS which is w/o stupid sensors

Yes, you really should do that. A few of the guys over here have done that.

And IF your car has iDrive/Nav... you should have the european TMC channel activated so you can see real time traffic updates and news thru the iDrive.

Sylon · 01-26-2013, 07:55 AM

Quote:

Originally Posted by rking117

nitrogen also expands and contracts. you will see the warning but it might take longer. The gas is more dense if i remember right. Sylon I dont think i could do without you here to keep me straight. Oh and everytime i see your icon I think Girl 1er = cool then only to realize its just Sylon.

Yeah, I'm not Alessandra Ambrosio. Sorry to disappoint, lol.

ric80 · 01-26-2013, 11:35 AM

how do you reset?

Suprgnat · 01-26-2013, 11:54 AM

Quote:

Originally Posted by Sylon

Hit it right on the head. Completely normal.

Although my tires are filled with nitrogen, so I'm not expecting to see these low pressure warnings. But we'll see.

Given that PV=nRT, if the only change is temperature then the pressure change will be the same regardless of the type of gas filling the tire.

Dackelone · 01-26-2013, 12:03 PM

Quote:

Originally Posted by ric80

how do you reset?

While the engine is running, scroll thru the BC using the turn signal stalk (or use the iDrive). When you scroll over to the tire TPMS icon, hit the reset button on the end of the turn signal stalk, then DRIVE the car until the reset light goes off.

You can not reset the TPMS while the car is in motion. The car must be stopped. Reset then DRIVE the car for a mile or two.

Sylon · 01-26-2013, 12:29 PM

Quote:

Originally Posted by Suprgnat

Given that PV=nRT, if the only change is temperature then the pressure change will be the same regardless of the type of gas filling the tire.

All I know is, I haven't had any issues since, and temps here have been as low as 6F. Maybe things will be different if we go into the negatives.

Plus, it was free, so what do I care?

PUREPHAZED · 01-26-2013, 01:05 PM

Quote:

Originally Posted by Dackelone

And IF your car has iDrive/Nav... you should have the european TMC channel activated so you can see real time traffic updates and news thru the iDrive.

??? How? Where? That would be AMAZING!

Best,

M

Dackelone · 01-26-2013, 01:38 PM

Quote:

Originally Posted by PUREPHAZED

??? How? Where? That would be AMAZING!

Best,

M

Are you coming to the Welt 4.0 car show? (see the sticky in the European sub forum) There will be someone there to code your car.

There are lots of coder's over here who can do this for you if you can't make the show.

Suprgnat · 01-26-2013, 01:50 PM

Quote:

Originally Posted by Sylon

All I know is, I haven't had any issues since, and temps here have been as low as 6F. Maybe things will be different if we go into the negatives.

Plus, it was free, so what do I care?

Nitrogen is a better choice for a several of reasons. Just commenting on pressure.

01-25-2013, 07:15 PM	#1
ric80 New Member Drives: 128 convertible Join Date: Sep 2012 Location: annapolis, md Posts: 17 iTrader: (0)	Cold weather and check tire lights Hi All-- So the temperature drops and I get a big warning that all my tires need air, I shouldn't drive over 50F, etc... Whats up-- is this normal?
	Tweet

01-25-2013, 07:26 PM	#4
ShocknAwe Lieutenant Drives: 2010 135i Join Date: Jul 2012 Location: Charleston, SC Posts: 452 iTrader: (3)	Cold air is denser, molecules slow down blah blah. Essentially warm air higher pressure, cold air lower pressure. Add more air if it's going to be cold for a while, try to keep it around specs. Your tire pressure rises a little when driving after the rubber heats up too. If you added warm air, the molecules were spaced out more, when it got cold, they crammed in closer. The colder it gets the lower the pressure goes and the TPMS I believe sense a 10% reduction, which isn't much. __________________ 2010 135i M-Sport 6MT Jet Black N54

01-25-2013, 08:35 PM	#7
rking117 Lieutenant Drives: Z4 3.0i & 128i Join Date: Aug 2012 Location: Central Florida Posts: 501 iTrader: (0)	yes it is likely to happen more when it is cold. Think about it when most things get cold they shrink. same thing happens to the air molecules. When this happens tire pressure goes down. It is easy to see a fluxuation of a few PSI with as little of a variance of 10 or more degress. __________________ Enjoying an E89 Z4, E82 128i and Fiat Pop 500 / Missing my E85 Z4 (sold)

01-25-2013, 08:57 PM	#8
Suprgnat Private First Class Drives: 2013 128i Le Mans Blue/Oyster Join Date: Jan 2013 Location: California Posts: 123 iTrader: (0) Garage List 1964 Austin Healey ... [0.00] 2003 Honda CRF230F [0.00] 1995 BMW R1100RSL [0.00] 2013 128i [0.00]	Ideal Gas Law PV=nRT http://en.wikipedia.org/wiki/Ideal_gas_law

01-25-2013, 11:47 PM	#10
rking117 Lieutenant Drives: Z4 3.0i & 128i Join Date: Aug 2012 Location: Central Florida Posts: 501 iTrader: (0)	nitrogen also expands and contracts. you will see the warning but it might take longer. The gas is more dense if i remember right. Sylon I dont think i could do without you here to keep me straight. Oh and everytime i see your icon I think Girl 1er = cool then only to realize its just Sylon. __________________ Enjoying an E89 Z4, E82 128i and Fiat Pop 500 / Missing my E85 Z4 (sold) Last edited by rking117; 01-25-2013 at 11:53 PM.

01-25-2013, 07:24 PM	#2
08LMB135i Private First Class Drives: 2008 Lemans Blue 135i M Sport Join Date: Aug 2012 Location: Calgary Alberta Posts: 123 iTrader: (0)	Pressures will drop with low temperatures, try upping your pressures just a bit.

01-25-2013, 07:32 PM	#5
mryakanisachoad Lieutenant Drives: '13 550xi + '09 M5 + '10 135i Join Date: Jun 2010 Location: Brooklyn, NY Posts: 527 iTrader: (0)	Normal

01-25-2013, 07:45 PM	#6
ric80 New Member Drives: 128 convertible Join Date: Sep 2012 Location: annapolis, md Posts: 17 iTrader: (0)	You guys all get warnings when it gets cold? I think it is strange.

01-26-2013, 03:42 AM	#11
RimasRS Lieutenant Colonel Drives: 135i MT 2009 AW Join Date: Sep 2010 Location: Europe Posts: 1,752 iTrader: (0)	1st I hate TPMS 2nd I have those warning lights when it is cold. But I've read somewhere that it is normal to see warnings when weather gets colder because TPMS sensors measures the temp also when it changes dramatically they give you warning light "check pressure in your tires then reset"

01-26-2013, 05:34 AM	#12
Dackelone Moderator Drives: 135i Silber mit/Rot 6MT N54 Join Date: Feb 2010 Location: Bayern, Germany Posts: 13,335 iTrader: (0)	The TPMS is a "dumb" system. Meaning... when its 80'F out and you set the TPMS target pressure... and then the temp drops.... the TPMS is still looking for that higher (tire)pressure, hence the light come on. When ever you check your tire pressure... you should ALSO reset the TPMS so it knowns the new "target" pressure. You should be checking your tire pressure every third fill up anyways. But see the problem no one does, and Congress stuck us with this crappy TPMS. __________________ Dackel's European Delivery Museum Guide 1addicts at Stelv1oPass 1addicts at Stelv1oPass 2.0 July 20th & 21th, 2013

01-26-2013, 05:39 AM	#13
RimasRS Lieutenant Colonel Drives: 135i MT 2009 AW Join Date: Sep 2010 Location: Europe Posts: 1,752 iTrader: (0)	The funny thing is that I had maybe 100 times warning light and non of them showed the real problem. I am really thinking to code out that system and activate European TPMS which is w/o stupid sensors

01-26-2013, 11:35 AM	#16
ric80 New Member Drives: 128 convertible Join Date: Sep 2012 Location: annapolis, md Posts: 17 iTrader: (0)	how do you reset?

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