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Discussion Starter · #1 · (Edited)
Here in NYC area it has gotten down to around 33 degrees in the mornings this week and my X3 has exhibited the following behavior.

1. tire pressure warning comes on and stays on at start up. After I go thru the reset button routine about three times it goes away. Yes I check my tires to make sure they arent flat -- tho I havent checked the exact rpessure. I will do that but should I have to when they are obviously at good operational inflation? Car did this a lot last winter too.

2. Coolant level indicator stays on for abuut 90 seconds after warm up. Then goes away. I have not checked the level -- will do so. This happened last year and I just added some water to system and it went away. I dont think there is a leak -- nothing on garage floor and the car was fine during hot weather just two months ago.


So are these just your basic problems related to shifts in the systems due to temperature and expansion/contracion of air in the tires and hoses? car drives great as always and temp gauge stays pegged at half mast.

PS -- just checked the tires. each one is at 30psi (this seems low and makes me wonder if my tire gauge is correct -- checked it on my wife's sienna with run fats and it read 32psi) the tires appear properly inflated with a slight sidewall bulge -- no sidewall touching the ground cdrtainly)

opened the radiator cap with the car stone cold and the indicator bar was down at the bottom -- dont see any fluid in there at all. not sure if thats normal for a stone cold engine.

any thoughts? thx
 

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Tar Heel Faithful
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First of all, the appearance of the tyres is never, and I repeat, never a good indicator of whether the tyre is up to proper spec. Always check the tyre pressure in the morning and correct as needed. If you want to try and prevent a low reading, inflating it a bit higher to 2,3-2,4 bar (33-34 psi) might help. Seeing as how I run 2,6 bar (nearly 38 psi) don't worry about overinflating.

When checking the coolant, follow the instructions on the instruction tab next to the cap. The top of the dipstick should be minimum level with the top of the tube. Maximum is where the second "bubble" in the dipstick is level with the top of the tube.
 

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the warning light on the tires is coming on because the low temperature drops the pressure in your tire. As mentioned above, put another 2 psi in there when measured on a cold day. This will definitally fix the warning problem. Probably that last time you filled the tires was when it was much warmer above 70 degrees, so now that it is 33, the air that was in there is now condensed. Filler up and grab a tire presser tool from advanced auto.
 

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Discussion Starter · #4 ·
thanks - are you saying that a stone cold radiator should be at the levels you mentioned. or after warmup. Mine is very much lower than those levels you mentioned and I dont see any fluid in there. Can I top off with water or get some AF? thanks
 

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You had it right! Cold contracts, heat expands. Since you are under warranty swing by the BMW store and have them check the coolant level and top off (free) if necessary for peace of mind. :thumbup:
 

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Here in NYC area it has gotten down to around 33 degrees in the mornings this week and my X3 has exhibited the following behavior.

1. tire pressure warning comes on and stays on at start up. After I go thru the reset button routine about three times it goes away. Yes I check my tires to make sure they arent flat -- tho I havent checked the exact rpessure. I will do that but should I have to when they are obviously at good operational inflation? Car did this a lot last winter too.
Happens here too. First cold snap. My dealer warned me about that at a New Owners Dinner. Just reset after checking pressure. That should take care of it. It does here until we get to 0 degrees, then it seems to happen again:mad:
 

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Discussion Starter · #7 ·
alrightythen -- gonna put a little water in the radiator and pump up the tires. then... fuhgetabooouutit!
 

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-- gonna put a little water in the radiator
Distilled water is recommended,
and as you topped off with water last year, you might be short of the 50/50 strength now.

As UncleJ said, any BMW shop will probably be happy to quickly top it off with coolant or mix at no charge.
 

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Here's my recent experience... $394 worth.. There is a hose betwen engine and radiator at the lower front passenger side. On this hose is attached a temperture sensor. It is attached by way of some nipple extension on the main hose. When the out side temperture is cold, the nipple binding around the sensor leaked - very, very litttle. When the engine warmed up, it stopped. I would half to add about a pint every 6 months to compensate. After the 3rd refill, I had BMW check it out - naturally I'm out of warranty. The service mechanic said that the nipple had gotten brittle and would thus would leak when the rubber was cold. There wasn't any real trace of leakage to show this, just high pressure test and mechanic that has seen this before.
This is on an 05 X3 with 44K miles. I'm beginning to wonder about BMW and it's legendary superiority.......
 

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Tire pressure monitor system on mine is still coming on when it gets cold. Spoke to the dealer, they checked the pressure and reset it and said I was good to go. Next morning - Hello there light! Still comes on. Another reset took care of it. Something about the sensors does not like freezing temperatures.
 

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Odd about the pressure light. I routinely go from -20 in the winter in CO to +90 in the summer in OH and SC with no problems. Periodically check the pressure with a gage and all is well.

Cheers
 

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This problem used to happen with alarm sensors in cars years ago. It was actually caused by the circuitry contracting because of cold weather and engaging the alarms.

The only way I know to fix it at this type is to give it a quick 2 psi which seems to effectively release the alarm indicator. Almost as if it is a latching relay they gets freed up.

Happened in both my 07 and 08.
 

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Odd about the pressure light. I routinely go from -20 in the winter in CO to +90 in the summer in OH and SC with no problems. Periodically check the pressure with a gage and all is well.

Cheers
That's because we're blessed with the ABS sensors that measure relative tire rotation speed, not actual pressure.
 
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