BMW 3 Series Thermostat replacement?

Question

My 2003 BMW 325i has not been heating up properly for a few weeks now. The temperature gauge starts to move towards warm, but then falls back down to cold, and no matter what temperature I set the heat to, it continues to blow cold air. I had an oil change today, and had my coolant topped up, but the problem remains. Will I need to replace my thermostat, and if so how expensive is it?

Answer 1

If your thermostat is stuck open your car will almost never warm up. My buddy has this problem so for now he covers his radiator (about 2/3) with a cardboard. It doesn't completely solve his problem but it get his car (a) going (b) slightly warmer for heating

If this works for you then you definitely have stuck thermostat.
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Usually thermostat can be done in 1 hour labor.

You have a BMW and the cost is probably more (more stuff to remove and re-install). I know everything cost more on my audi.

If you go to your dealer, don't say "I want my thermostat replaced". They will replace it whether you need it or not. Tell them what is wrong and let them decide if it is the thermostat.

Good Luck

P.S. NEVER top off with water. It will freeze and crack your engine block. At best, it will freeze inside your heater core (the part that warms up your cab) and will never blow warm air.

Answer 2

It depends if the 2003 325i has an electric fan or a viscous coupling fan (ie; engine powered fan).

My 2000 323ci has a viscous coupling fan and that has to be removed in order to access the thermostat. I had to get some loaner tools from Autozone to undo the fan.

If your car has an electric fan, then it's a lot easier.

bavauto.com has the parts. The thermostat runs for about $60 I believe (just check it out at www.bavauto.com).

You might as well also do a complete coolant (antifreeze) change as well since removing the thermostat will cause some loss of coolant anyway. So instead of just topping it up, drain it (plastic drain valve located bottom corner of radiator), stick a garden hose into the system (with thermostat removed) and finally install new thermostat and refill it.

You may use either distilled water with BMW coolant or try the "waterless" coolant from bavauto.

If you want the dealer to fix this, they will most likely charge you 1 to 1.5 hour of labor for this job. But everything will be marked up considerably - including parts and supplies...etc.

Answer 3

2000 Bmw 323i Thermostat

Answer 4

This most certainly sounds like your thermostat. Not only is it an easy fix with basic tools, it is cheap as well. Perhaps one of the least expensive things to fix on a BMW. Try Autohaus AZ for OEM replacement parts and do the job yourself! They have helped me many times and now have the satisfaction of doing service on my car for much less than taking it to the shop. Visit their website here: http://www.autohausaz.com
Your thermostat is located on the top right side of the engine block, just below the valve cover. If you follow the intake hose from your radiator, it will go to a metal housing on the engine block. It is in that housing that you will find the thermostat. Should be a 13 or 15 mm allen bolt (two of them). Make sure to scrape the housing clear of any remaining gasket material and don't forget to install the new gasket. One should come with the thermostat kit. All in all you will probably only spend $30 to replace this. Your car will actually run better and your heater will now work. Sure beats spending over $200 for the repair at a BMW shop.
Hope this info helps and good luck servicing your car.
Just love the BMW in-line 6..... easy to work on and lasts FOREVER!

Answer 5

you will need to see a mechanic it is a common fault on one of the bmw models , the thermostat is electriclal and water gets in the connections [design fault]