330itis 15 Report post Posted July 10, 2008 My 330ci has some cooling problems. On open roads the temp needle goes down slowly. (sometimes all the way into the blue) as soon as I slow down and hit suburban areas its fine It warms up quickly from first start up, and it has plenty of water with no air lock. Havent really investigated it very deeply yet, just thought Id ask the BMW brains on here to see if this is a common fault. My theory is that coz its so cold and its an auto and cruises at about 2000rpm its just being over cooled? Where I was driving it it was about 3 degrees celsius. is this common? Quote Share this post Link to post Share on other sites
jochen 4 Report post Posted July 10, 2008 (edited) My 330ci has some cooling problems. On open roads the temp needle goes down slowly. (sometimes all the way into the blue) as soon as I slow down and hit suburban areas its fine It warms up quickly from first start up, and it has plenty of water with no air lock. Havent really investigated it very deeply yet, just thought Id ask the BMW brains on here to see if this is a common fault. My theory is that coz its so cold and its an auto and cruises at about 2000rpm its just being over cooled? Where I was driving it it was about 3 degrees celsius. is this common? There is only one device that can allow over-cooling on open roads to occur: the thermostat. Replace it, it will be stuck open. Over-cooling due to a stuck thermostat is common and very easy and cheap to fix. Do it ASAP as an engine running below operational temperature will use more fuel and will wear out faster. Edited July 10, 2008 by jochen Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted July 10, 2008 Thermostat is faulty. Its a plastic housing and one of the supports for the thermostat will be broken allowing it to stay open all the time. It comes as one piece, thermostat & housing. Check the water pump too and the transmission thermostat if its an auto...they break too. The expansion tanks on these also explode, so get it checked properly by someone who knows what they are doing. You dont want this vehicle to get overheated. You must be very vigilant with these vehicles regarding there cooling systems. The plastic cooling system components start deteriorating on all the late model cars when they get to around 5 years old. All the plastic is recycled plastic and doesnt last long. Same for Audi VW and most other cars produced in europe. Japanese manufacturers are still allowed to use virgin plastic in there manufacturing and the jap components normally last 12-15 years. I'd get your car checked pronto....other components may not be up to standard either Cheers Glenn Quote Share this post Link to post Share on other sites
330itis 15 Report post Posted July 11, 2008 I guessed the thermostat aswell. Only thing that made me think twice is the fact that it warms up quick. I will replace it asap tho Thanks for the info! Quote Share this post Link to post Share on other sites
