Author Topic: Quick BMW antifreeze/coolant question (Read 6715 times)

iamthatis · « **on:** April 10, 2012, 06:59:15 PM »

My newly bought 318i showed me today that when idling, it will make the temperature rise untill i freak out near red and turn the car off, or turn off to an open road and drive untill it moves back to normal operating temp.
After some searching it seems like a poorly bled cooling system.

Either way, i've been planning to work on the cooling system anyway. I'm buying new water pump, thermostat, belts, and some BMW coolant from Pelican Parts.

it says our cars need a 50/50 mix. Now, my question, is the BMW antifreeze already premixed? So i just need to get 2 1-gallon jugs of this stuff and fill it up? OR is it pure antifreeze and i need to get some distilled water and make a half-n-half solution?

Also, how hard is it to Do this? I never messed with the cooling system of a car.

DesktopDave · « **Reply #1 on:** April 10, 2012, 08:12:18 PM »

Does your aux cooling fan ever turn on? How well does the engine-driven fan work? Those are more likely culprits than a bubble in the system.

Cooling system is fairly easy, though the pump flanges can crack, as well as the thermostat housing. Just take your time, it'll all work out. Also beware that the bleeder screw is very fragile, only use a flat-bladed screwdriver to turn it. Maybe order a spare & replace that as well. I cracked one myself and it put the car out of action until I could go to the dealer and get another one. Stupid $3 part...or just a dumb owner, same difference, eh?

I thought the BMW stuff comes full strength. I use Prestone and Water Wetter myself...with a big bucket and a funnel. I tend to make it watery to improve cooling efficiency...like 2g dist water to 1g coolant. Most other people will do 1gal of both.

Then I pour the extra back into the coolant jug & take it along with me. It stays in the car all the time now.

keflaman · « **Reply #2 on:** April 10, 2012, 09:01:34 PM »

I started using these in every BMW I own: http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=17-11-1-712-788-M230&catalog_description=Bleeder%20Screw%20for%20Expansion%20Tank%20%28Brass%2C%20includes%20one%20O%2DRing%29%2C%20E%33%30%20%33%31%38i%20M%34%32%2C%20%33%31%38iC%2C%20Each%09%20%20

iamthatis · « **Reply #3 on:** April 10, 2012, 09:17:15 PM »

The engine driven fan seems to work well. It spins well, it's not missing blades or broken. Not sure how to tell a poorly working one.
I'll check the aux fan tomorrow.

That screw is in my shopping cart.

anything else i should look for?

The radiator doesnt appear to be cracked anywhere. Actually doesn't look original, doesnt look like a 22 year old radiator. Nothing is leaking. The hoses seems fine.

monty23psk · « **Reply #4 on:** April 10, 2012, 10:39:04 PM »

BMW coolant is not pre-mixed, you need to supply water, distilled is prefered. But the m42 has a low capacity. You just need one gallon on each.

iamthatis · « **Reply #5 on:** April 11, 2012, 10:37:53 AM »

Quote from: monty23psk;111780

BMW coolant is not pre-mixed, you need to supply water, distilled is prefered. But the m42 has a low capacity. You just need one gallon on each.

Excellent, just what i wanted to know. Thank you.

deansweet · « **Reply #6 on:** April 11, 2012, 06:26:28 PM »

You really only need to buy a single gallon of OEM coolant and a gallon of distilled water. Our cars hold ~1.7gals ttl. I bought two as well from local BMW dealer for $26/gal because you never know when you might need extra for future use?

Chart from Bentley guide I used:
Coolant Capacity
M42 - 6.5l (6.9US Qt.) = 1.72500 Gallons