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Read the WELCOME ALL BMWFANATICS post.
How to drain Coolant e90
- Thread starter Bmwed
- Start date
Chucky
Active member
This is the process for an e46 but would imagine the process to be very similar on an e90.
To begin the process or draining the radiator, first open the Radiator cap.
Remove Big Blue Drain Plug
Next get underneath the engine / car where the splash shield was removed and locate the big blue drain plug.
How to Remove Blue Drain Plug
Open and remove this drain plug with a similar tool or flat head screw driver and watch for the water that starts pouring out immediately. Also make sure the drain plug does not get lost.
Coolant will be pouring out now.
Loosening The Smaller Blue Drain Plug
Only loosen this second smaller blue drain plug (turn it a couple of times round with a flat head screw driver) and let the remaining water drip out.
Radiator - Draining
NOTE: Coolant is poisonous, if any leaks on to the ground, wash it away with water. As it is sweet, animals tend to drink / lick it.
Radiator - Bleeding
Now to bleed the radiator to enable all the water to come out, turn the black bleed / vent screw a few times to loosen it, with a flat head screw driver.
Radiator - Flushing
Next fit the big blue drain plug back and also the smaller blue drain plug (but not too tight, as you may damage them) and fill the radiator with water. I used tap water myself, but if you prefer, you could use distilled water.
Next close the radiator cap and tighten the black bleed / vent screw and either take the car for a short drive or start the engine and rev it a for a few minutes. This will enable the water to mix with / dilute any remaining old coolant.
NOTE: Do not over tighten the bleed / vent screw, it will / can break in half...as happened to me!
Filling Ionised Water and Coolant
Make sure the radiator isn't too hot, then slowly open the Radiator cap again open and remove the big bottom blue drain plug again, loosen the smaller blue drain plug and then loosen the top bleed / vent screw again. Then wait for all the water to drain out, it may take about 10 minutes.
Next close and tighten the bottom blue drain plugs (not too tight).
Turn the heating on full in the car and pour the required ratio of water to Coolant into the Radiator. This will be written on the Coolant bottle, is 1.5 litre of Collant to 3 litre of water, so to get the total correct, roughly about 1 full bottle of coolant + 250ml from the second bottle and 3.25 litres of water.
Radiator Full
Pour until the orange stick sticks out as below, indicating it is full.
19Heating On Full
Close the Radiator cap and tighten the black bleed / vent screw next to it.
Now turn on the engine and rev it for about 5 minutes, also turn on the car heating to full temperature. All these will bring out any air trapped in the pipes.
Radiator - Bleeding
One you have done that, leave the engine running and open the Radiator cap and loosen the black bleed / vent screw until water starts coming out of the hole. This process gets rid of the trapped air. Now you may need to pour a little more water / coolant in the Radiator again, to fill it up.
Follow this procedure as many times as you like, while revving the car.
Once satisfied, fix the splash shield back to the bottom of the car, tighten the Radiator cap and tighten the bleed / vent screw (again not too tight).
One method to tell if all the trapped air has been released, is to ensure you are getting constant hot air from your air vents inside the car. If it fluctuates, it means there is more to bleed.
Final To pup Water & Coolant
Once the car has completely cooled down, open the radiator cap once again and top up the radiator with water & coolant (till the yellow stick sticks out again), as it will usually be required.
:thumbs:
Edit taken from http://www.impee.co.uk
To begin the process or draining the radiator, first open the Radiator cap.
Remove Big Blue Drain Plug
Next get underneath the engine / car where the splash shield was removed and locate the big blue drain plug.
How to Remove Blue Drain Plug
Open and remove this drain plug with a similar tool or flat head screw driver and watch for the water that starts pouring out immediately. Also make sure the drain plug does not get lost.
Coolant will be pouring out now.
Loosening The Smaller Blue Drain Plug
Only loosen this second smaller blue drain plug (turn it a couple of times round with a flat head screw driver) and let the remaining water drip out.
Radiator - Draining
NOTE: Coolant is poisonous, if any leaks on to the ground, wash it away with water. As it is sweet, animals tend to drink / lick it.
Radiator - Bleeding
Now to bleed the radiator to enable all the water to come out, turn the black bleed / vent screw a few times to loosen it, with a flat head screw driver.
Radiator - Flushing
Next fit the big blue drain plug back and also the smaller blue drain plug (but not too tight, as you may damage them) and fill the radiator with water. I used tap water myself, but if you prefer, you could use distilled water.
Next close the radiator cap and tighten the black bleed / vent screw and either take the car for a short drive or start the engine and rev it a for a few minutes. This will enable the water to mix with / dilute any remaining old coolant.
NOTE: Do not over tighten the bleed / vent screw, it will / can break in half...as happened to me!
Filling Ionised Water and Coolant
Make sure the radiator isn't too hot, then slowly open the Radiator cap again open and remove the big bottom blue drain plug again, loosen the smaller blue drain plug and then loosen the top bleed / vent screw again. Then wait for all the water to drain out, it may take about 10 minutes.
Next close and tighten the bottom blue drain plugs (not too tight).
Turn the heating on full in the car and pour the required ratio of water to Coolant into the Radiator. This will be written on the Coolant bottle, is 1.5 litre of Collant to 3 litre of water, so to get the total correct, roughly about 1 full bottle of coolant + 250ml from the second bottle and 3.25 litres of water.
Radiator Full
Pour until the orange stick sticks out as below, indicating it is full.
19Heating On Full
Close the Radiator cap and tighten the black bleed / vent screw next to it.
Now turn on the engine and rev it for about 5 minutes, also turn on the car heating to full temperature. All these will bring out any air trapped in the pipes.
Radiator - Bleeding
One you have done that, leave the engine running and open the Radiator cap and loosen the black bleed / vent screw until water starts coming out of the hole. This process gets rid of the trapped air. Now you may need to pour a little more water / coolant in the Radiator again, to fill it up.
Follow this procedure as many times as you like, while revving the car.
Once satisfied, fix the splash shield back to the bottom of the car, tighten the Radiator cap and tighten the bleed / vent screw (again not too tight).
One method to tell if all the trapped air has been released, is to ensure you are getting constant hot air from your air vents inside the car. If it fluctuates, it means there is more to bleed.
Final To pup Water & Coolant
Once the car has completely cooled down, open the radiator cap once again and top up the radiator with water & coolant (till the yellow stick sticks out again), as it will usually be required.
:thumbs:
Edit taken from http://www.impee.co.uk
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