BMW E90 E92 E93 2006-2011 325i 328i 330i Radiator Replacement

Make sure the engine is completely cooled off prior to working on the cooling system.  Safely jack up the front end of the car and support it on jack stands.  For this project I used a Nissens brand radiator.  The quality and fit was outstanding and it is the cheapest out of the three different brands that we sell. This project was done on a 2007 BMW 328xi, other models may have slight variations to the procedure but most E90, E91, E92, E93 cars 2006-2012 should be pretty much the same.  Radiator replacement on E90-E93 BMW 3-seires is fairly simple and can be done by almost anyone with basic mechanical knowledge and simple hand tools. 

1. Remove the under panel and drain the coolant.

2. Once you unscrew the radiator drain plug, unscrew the expansion tank cap to let the air into the cooling system and increase the coolant flow out of the drain.

3.  Unscrew the two screws that hold the air duct to the radiator support.

4.  Unscrew the two 10mm bolts for the air filter box.

5.  Loosen the air intake boot clamp and unplug the air mass sensor.  Be careful not to damage the air mass sensor connector.  To unplug it use something sharp to lift up the clip and pull off the plug.  Remove the air box.  Now is a good time to check the condition of your air filter.

6.  Next you need to remove the fan.  Unscrew the torx screw on the passenger side of the car.

7.  Unplug the electrical connector.

8.  Remove the torx screw at the bottom of the fan that holds the oil cooler to the fan housing.

9.  On the driver's side of the fan shroud unclip the fan from the radiator while pulling up on the fan.

10.  Unclip the coolant overflow hose from the fan housing.

11.  Remove the fan from the car.

12.  Start disconnecting all of the hoses that are attached to the radiator.  My advice is to order new upper and lower radiator hoses.  Old hoses are so hard to get off that there is a chance you'll damage them while trying to disconnect them.  If you do end up getting the old hoses off without damage feel free to return the new hoses you didn't use.  By the way, Nissens radiator comes with new upper and lower radiator hose o-rings but it does not come with o-rings for the two smaller hoses so you might want to order those.

Disconnect the upper radiator hose by removing the metal clip and pulling the hose off the radiator neck.  It will definitely take some force to get it off.

13.  Disconnect the lower radiator hose.

14.  Disconnect the small coolant hose at the bottom of the radiator on the passenger side.

15.  Disconnect the small coolant hose on the driver's side of the car by removing the torx screw.

16.  We are almost ready to remove the radiator.  The radiator is held on to the car with two torx screws at the top and two clip on mounts at the bottom.  Remove the driver's side screw.

17.  Remove the screw on the passenger side.

18.  Unclip the lower mounts and remove the radiator.  You can ether drop it down if you have enough clearance or remove it from the top.

 

19.  Reinstall everything in reverse order.  When installing the hoses, replace the o-rings and lube the o-rings with fresh coolant prior to installation.

Once everything is installed you will need to fill and bleed the cooling system.  Be sure to only use coolant recommended for BMW.  Original BMW coolant is blue so if you got some other color in the cooling system be sure to flush the coolant out completely.  Most modern coolants are make specific and are not mixable.  My car had some unknown green/brown coolant, probably a mix of a bunch of different types of coolant.  I ended up filling and draining the cooling system with water about 5 times until there was nothing but clean water draining out.  

Because the car is equipped with an electric water pump you will have to follow specific procedure to bleed the cooling system prior to starting the engine.  Here is how you bleed the cooling system on an E90-E93 BMW:

• Open the bleeder valve on the coolant expansion tank.
• Fill the expansion tank with coolant until a steady stream of coolant is coming out of the bleeder screw.
• Close the bleeder screw, fill the coolant to the lower edge of the filler neck and close the expansion tank cap.
• Turn on the ignition without starting the car.  
• Set the heater to the maximum temperature and set the fan speed to the lowest setting.
• Depress the accelerator pedal to the floor for at least 10 seconds.  You should hear the water pump turn on and start circulating the coolant.
• It is recommended to have a battery charger hooked up to the car.  Bleeding procedure takes about 12 minutes and can drain the battery.  If you don't have a battery charger at least be sure to turn off the headlights and the radio.
• Once the car is done doing its thing, unscrew the expansion tank cap and add some more coolant until the level indicator is 6mm above the max mark.
• Start the car, let it warm up and check for leaks.