DIY Radiator Flush

I've been busy all afternoon doing this, then spent nearly all evening put it on a webpage...my hands are very tired!!!

I hope some will find my DIY Radiator Flush helpful.

http://www.impee.co.uk/radiator_flush.htm

impee.

I stuck a hose in every hole I could find until everything ran clear.

Edit: Your DIY is close but you are supposed to fill it with the heat on full blast.

done that last week.....what a MESS!!!!

willsbma, thanks for the tip, I will change my notes.

one thing i wanted to ask is that, once i finished, i parked my car and went in. 1 hour later a kid from outside rang the bell and told me that my car is making noises. i ran out and heard the radiator fan on full...i took the car for a spin, incase it needed settling down or water needed to flow through all the pipes for it to stop, but it still didn't.

the only way it stopped is when i unplugged the fan cable and then put it back. since then every 30mins i go out and check the car and its fine...very paranoid now!

does anyone have any idea what that was???????

thanks.

you should also drain from the other blue plug, the one just to the right on the one you did losen... another thing you didnt point out in your DYI is the block drain, to drain the coolant from the block.

http://www.bmw325i.net/maint_coolant_change.shtml

Originally Posted by dakkon

you should also drain from the other blue plug, the one just to the right on the one you did losen... another thing you didnt point out in your DYI is the block drain, to drain the coolant from the block.

http://www.bmw325i.net/maint_coolant_change.shtml

damn...It looks like I missed a couple of other things too...its becuase I couldnt log into e46fanatics on the day to search for a DIY for this!!!

If I haven't drained the block, does it make a big difference? or can I leave it till 2 years later when I flush it again?

impee.

The pictures with your DIY are excellent.

As mentioned above, you left out the engine block draining. Without draining it, you still have old coolant mixed with the new.

Also, I think I would change the name from "Radiator Flush" to Engine Coolant drain and refill.

Originally Posted by impee

willsbma, thanks for the tip, I will change my notes.

one thing i wanted to ask is that, once i finished, i parked my car and went in. 1 hour later a kid from outside rang the bell and told me that my car is making noises. i ran out and heard the radiator fan on full...i took the car for a spin, incase it needed settling down or water needed to flow through all the pipes for it to stop, but it still didn't.

the only way it stopped is when i unplugged the fan cable and then put it back. since then every 30mins i go out and check the car and its fine...very paranoid now!

does anyone have any idea what that was???????

thanks.

My fan was staying on when the car was off. I had to un-plug when stopped and then plug it in when I drove. PITA. One time I went to the store and it did shut off by itself, I expected it to be on when I came back out but it was still off. I thought I got lucky for a minute but then when I got home and shut the car the fan stayed on again. So it was a fluke and I still had to buy the fan. Just watch it carefully. Either you kill the battery or kill the engine.

First of all, thank you impee for the DIY.

Second, anyone know why the fan is staying on? Is there a way to prevent this from happening?

You meant deionized water, not ionized.
You want low ion concentration in this water - ideally only the water's own H3O+ and OH- ions. Some contaminating metals, carbonate, organic ions etc. will negatively affect the engine's aluminum alloy and/or precipitate with coolant's buffer or preservative.
This is why the engine grade water is either purified by distillation or depleted by passing through ion exchangers.

that sounded so cool. haha i wish i could talk like that.

Dakkon made a great point above. If you follow this DIY you only swap a little over half the coolant. I appreciate the OP taking the time to put this together but I had to refer back to the Bentley as I was expecting to see 8.4 liters drain and I ended up getting about 4.5 liters.

If you read the linked DIY the OP replaces the drained coolant with 2.5 L of coolant and the same amount of distilled water. He puts in a total of 5 liters coolant.

The m54 and m52 (E46 2.5 & 3.0) engines have a coolant capacity of 8.4 liters.

You need to drain the engine block to get the remaining 3.5 liters out. It is a 13mm hex bolt on the exhaust side of the lower block below cylinder #2. (see photo). You will get another 3.5 L of coolant once you remove this drain plug. Put this plug back first, torquing to 25Nm (18ft/lbs) then follow the rest of the OP's DIY. Remember now that you will need an additional 3.5 L of coolant mixture.

Can anyone tell me if its a good idea or not to power flush my 2002 325ci coolant system?

No need to.
Drain block. Drain radiator and your good.

Would this by any chance solve an issue of my cars heat AND A/C only working while the car is in motion? When idling the heat and ac does not work

Originally Posted by aphhpa

Would this by any chance solve an issue of my cars heat AND A/C only working while the car is in motion? When idling the heat and ac does not work

That sounds like a bad thermostat.

Negative cause ive had my therm replaced and it still doesn't work unless moving

nice job on the DIY and I won't knock you for making it. I know they take a lot of work.

But I will mention that it's not necessarily the approved method to vent the cooling system which is why you may have experienced the cooling fan issue you mentioned.

When you drain the radiator, the coolant inside the engine block (3.5 Lt approx) does not come out of the radiator drain plug.
I think you should not flush it if you re not draining engine block.
If you flush it with water without draining the engine block, what happens is that the water you pour in will displace the coolant inside the engine block and when you add new coolant into the system with the 50/50 mix, that will become 25/75 mix (75% water and 25% coolant) when it mixes with the water sitting in the engine block.

That may have caused the fan to blow even when the engine is off because the higher proportion of water in the coolant system makes it to vaporize faster which creates high presure inside.

BMW Antifreeze/Coolant (50/50):
1 Gallon (3.78 Lt) of concentrated coolant, when you mix it with distilled water becomes 2 Gallons (7.56 Lt). BMW Service Manual says the exact volume to cover engine block and radiator is 8.4 Lt (for most models), so I guess it's good to have an extra bottle of coolant.

Engine-Block Drain Plug Location:


Radiator Drain Plug Location:

So would you need more than one bottle (gallon) of BMW concentrated coolant?