[Danny.B.]

Hi Folks

Whats the best way to do a full coolant drain as im changing the stats and figured i might as well put fresh coolant in too!

Id rather not get under neath the car if possible as this isnt something i can do easily at home!!

I was thinking of one of those Pela 6000 Syphons? which i was going to use for my oil change anyway? WOuld this work? Drain header tank, and then stick that syphon on the end of the hose that goes to the rad?

[parapaul]

A *full* coolant change is a bit of a pig. You essentially need to open the drain tap at the bottom of the rad (if there is one) or pop off the bottom hose, then run the engine up to temp so the 'stats open and allow a full drain - all the while topping up the header tank so it doesn't run dry.

Then you've got to add enough coolant to make it back up to the right concentration.

[Danny.B.]

Problem is the car has some pink coolant in, which may be fine, but id rather the bmw stuff in there.

So if i drain the coolant on a stone cold car im likely to have some old fluid in the system still?

But as my car isnt going any higher than 79c will warming the car up make any difference?

[Dr Dave]

It was all so easy when we had cylinder block drain plugs and radiator drains.

[mistryn]

The only way I can think of is to loosen a radiator hose, let coolant drain out, and pure fresh water in continously until it flush's it all out

[makkan00]

I have done it last year. Few things to cosider;
1- Remove the under engine tray, or loose the front screws of under engine tray.
2- There is a second tray, which you may need to loose from one side.
3- If I am not wrong, the coolant drain is on passenger side.
4- There is white outer body with blue screw in it. DO NOT rotate the white body. Stabilize the white outer body and only undo the blue screw.
5- When blue screw is slightly loose, you'd ideally run the car. Turning on the heater with compressor will open all the passages. mm
6- Once the car reaches at running temp, with all the caution (gloves and etc etc), undo the blue screw and let the coolant drain.mm
7- Once it is flashed, add some distilled water to remove any traces of old coolant.
8- When you are satisfied that only distill water is coming, let it completely drain.
9- Put the blue screw back in.
10- Rear the method of opening all the passaged by TIS (I cannot remember it now).
11- Start adding the coolant. When it is full, run the car for few minutes.
12- Bleed the air bubles from the bleeding valves.
13- Let the car cool down and put all the screws back.

Check the coolant for next 2-3 days.

OEM BMW coolant is £20 on ebay but stealers sell them for approx £12 including VAT. You'd require ionized to make the coolant 50% diluted. Ionized water gives you max rust free coolant.

HTH.

[Danny.B.]

thanks for that mate! but as i was saying is there any point me turning engine on to heat up and open passages if my temp isnt getting high enough anyway?

[makkan00]

Originally Posted by Danny.B.

thanks for that mate! but as i was saying is there any point me turning engine on to heat up and open passages if my temp isnt getting high enough anyway?

In that case, do it on the max temp which your car can do.

[Danny.B.]

As im changing my main stat i assume anything thats left in the system will piss out when i remove that anyway?

[Dr Dave]

Yes, definitely so. Thats how I did it, made sense to do it at the same time as it was due.

[coopersim]

I just used tap water

[makkan00]

Originally Posted by coopersim

I just used tap water

That should do, but for best results de-ionized water is recommended. (not the distilled water for battery top-ups in old days)

[Dr Dave]

Tap water with proper BMW antifreeze or a good quality OAT Based antifreeze will be just fine - I'd like to know what premix BMW use at the factory.

[Phil325i]

Originally Posted by Dr Dave

I'd like to know what premix BMW use at the factory.

Surely the mix strength will depend on the destination market of the car. AFAIR a 50/50 mix covers you down to -40.

[2007NC335i]

First, please allow me to apologize, as I realize there are a number of posts on this general topic, but I have had a hard time finding a specific one for my application... 2007 335i US Manual Transmission, non-sport package.

I am looking to flush the coolant and it appears that this is not a trivial task, as to get to the radiator drain plug, you have to remove the FMIC (Front Mounted Intercooler).

My questions are as follows...

1) What is the easiest way to drain the coolant... I don't need to get every drop out - I just want to get the majority of the fluid?

2) I've been told to remove the lower radiator hose.... is this the way to go or is there another method for my specific car? I've got an 81 Corvette that I work on and would have no problem doing this on that vehicle, but does anyone have a very specific picture with a very specific procedure for removing the hose where it attaches to the radiator. I didn't see any simple 80's era screw clamps. :-)

3) I do not have access to a lift and consequently I usually just jack up the right side of my Corvette, put a car ramp under the right front and right rear tires and then do the same on the left. Is there a safe way to do this on my 335i? If not, what is the prescribed method for getting all 4 wheels into the air?

Again, please accept my apologies for this admittedly novice post - I just joined the forum and this is my first.

Any and all information would be greatly appreciated and pictures are worth a 1000 words, as I am not intimately familiar with the car yet.