Help with radiator refilling...

[maxslomoff]

elo,
so i switched out my water pump and thermostat.

when i pulled the water pump out a bunch off coolant dumped out all over the place. i guess i didn't drain the coolant with the heater on, apparently that lets the coolant flush out of the engine?...

anyway, i read that the e36 takes 10.6 quarts of coolant. i assumed since so much dumped out of the engine block i would have to put in the full amount. i poured in one gallon of distilled water and 1 gallon of radiator fluid concentrate, but by the end i had to pour in bit by bit and wait for it to settle. i thought i would have to turn the engine on to get the coolant to circulate. is that right?

turning the heater on didn't seem to work.

i just want to make sure i get this right -

[witeshark]

I suggest a search on cooling system bleeding; Those systems need very careful bleeding of air during refilling. Have a look in the E36 section.

[johnnyBgood]

witeshark is 100% correct.........follow these directions below carefully, you may have do this a few times.....just be patient...

It really helps to have a friend lend a hand by sitting in the car revving the engine and keeping an eye on the temp gauge. Start off by removing the coolant reservoir cap and the plastic bleeder screw right next to it. Fill the coolant reservoir with a 50/50 mix of coolant and distilled water. Have your friend start the car, turn on the heater to full hot on the vent position and rev the engine to about 2500 RPM, if the temp gauge goes past the 12 o'clock position, shut the engine off, let it cool down and start over again. Watch the coolant reservoir, as the engine warms up the coolant level should drop, refill as the coolant is sucked out of the reservoir. Watch the bleeder screw hole also, when coolant with no air bubbles begins to overflow then you're almost done. It's a good idea to have some paper towels handy to mop up any overflow. Screw the bleeder screw back in (be careful to not break the plastic screw) and continue to rev the engine, you should see a continuous stream of coolant spraying in to the reservoir from the small hole at the top. Continue letting that spray in to the reservoir while your friend revs the engine for a couple of minutes, until the gauge hits the 12 o'clock mark, to ensure any remaining air is gone. If the heater is blowing hot air when you're revving the motor AND when the engine is at idle then your cooling system is properly bled. If your vents are blowing cool air at idle then you still have air in the system, try revving the engine more and/or squeeze the radiator hoses to help dislodge any trapped air. Once your system is fully bled, top off the reservoir and replace the cap. Check the coolant level in a day or two and top off as needed.

How To BMW

johnny,

[cmiulius]

personal and no offense to anybody, the engine bleed himself.at least mine did that

[cmiulius]

that's why u have a coolant level sensor

[SHAHAB323IS]

Originally Posted by cmiulius

that's why u have a coolant level sensor

the coolant level sensor tells you when the coolant level is low in the expansion tank, it has nothing to do with bleeding, and the system is not self bleeding because the fill point is not the highest point in the system, it is very common to have air bubbles form from not using proper bleeding techniques. If you just filled yours and went, well good job, but that's not the proper way but if it works for you, all the better.

[cmiulius]

u are perfectly right,no question but when the air goes out the coolant level goes down so.........................

[94BMW325i]

You have to bleed the cooling system to get the air out, it's not like other cars. It will stay in the system otherwise. When you are filling cars the coolant level will go down a few times before you have the correct level, it needs to circulate, etc.

To the OP: Did you drain the coolant from the engine block by undoing the drain plug that is close to the exhaust manifolds? Wasn't sure if you mentioned that.

[drz]

Originally Posted by 94BMW325i

To the OP: Did you drain the coolant from the engine block by undoing the drain plug that is close to the exhaust manifolds? Wasn't sure if you mentioned that.

Exactly what I was thinking. If you didn't drain the coolant from the engine block, that would explain the big splash you got when you opened the system.

[johnnyBgood]

94325i You have to bleed the cooling system to get the air out,

Exactly......I replaced the waterpump & thermostat both in my e36 & my brother's e46 & both times the engine started to overheat until I had them both fully bled.....
johnny,

[SHAHAB323IS]

Originally Posted by cmiulius

u are perfectly right,no question but when the air goes out the coolant level goes down so.........................

Yeah, but what is your point, the air that gets trapped in the system when you drain the coolant then refill it will not go out by itself so...................