'89 325i Coolant Flush

Post Tue Jul 17, 2012 6:09 pm

It's a new buy so thought i'd give it a full service and flush the coolant etc. Drained the old coolant from bottom hose and from the block (19mm bolt). i can run the hose pipe through the expansion tank and let the water run through bottom hose but cant seem to do the same through the drain hole on the block....

Also when i removed the bolt from the block to "fully" drain the the coolant i was expecting liters of water as the system takes upto 10 liters, but it was merely dripping. Is this normal?

I'm a new to all things e30 and mechanics, and this is kinda a project for me. Have managed to fix on oil leak on the engine (oil pressure switch), and give the car a full service and just the coolant part is left, which is a bit confusing!

Any help is appreciated,

Cheers

Post Thu Jul 19, 2012 3:36 pm

Anybody.......

Post Thu Jul 19, 2012 3:38 pm

Moved to tech help: not really an M20/Forced Induction question.
You should get more views here.
Morat

Post Thu Jul 19, 2012 8:10 pm

Hi, if you remove the hose from the lhs of the thermostat housing you'll be able to flush the block through. I suspect it was only dribbling out from the drain plug because the thermostat is closed, sealing off the block from the rest of the system. hth

Post Thu Jul 19, 2012 8:53 pm

You mean remove that pipe and run a hose through it? I can flush the block as i have the rad?

Post Fri Jul 20, 2012 1:19 pm

jus tried it this morning.....still cant manage to flush the coolant from the block. still only a dribble.

And when i put the drain plug back in and bottom hose and go to fill the expansion tank. It takes no wear near 10 litres before it reaches cold level marker !

Post Fri Jul 20, 2012 2:54 pm

Try a bit of wire in the block drain hole. It's probably blocked with sludge.
Heater hose is the best place to flush from.

Post Fri Jul 20, 2012 9:21 pm

thanks i'll try that. Seems to only be a dribble of water coming from the block no matter what pipe i run the water through.

Where is the heater hose ?

Post Fri Jul 20, 2012 10:41 pm

satvir wrote:
Where is the heater hose ?

From the back of the head to the bottom heater stub pipe on the bulkhead.
Disconnect the hose at the bulkhead and connect your garden hose to the hose with a radiator hose off as well.

Post Fri Jul 20, 2012 10:47 pm

thanks mate. didnt know it would of been such an issue to flush the system.

Is the hose your referring any where on this diagram :

http://www.realoem.com/bmw/showparts.do ... g=11&fg=35

Post Fri Jul 20, 2012 10:50 pm

#12, but it doesn't look anything like the diagram in real life.

Post Sun Jul 22, 2012 9:00 pm

Managed to put a wire in the drain block and sure enough lots of shit old old dirty coolant came out!

So a success there and then i continued to flush the system till clear water was running out of the drain.

The next was step was a to add wynns coolant flush fluid (325ml) and top the rest of the system up with water etc. Start the car, let it idle for ten minutes and then to drain the coolant system once again, from rad and block....flush with hose to get rid of everything AND then to renew the coolant as usual!

HOWEVER, i've read online and seen in the bentley manual that the coolant system takes 10.5 liters! i added the 325 ml wynns coolant flush fluid and rougly 6 liters of water and ive gone just above the coolant level.

I pumped the hoses, opened the bleed nipple etc. But it appears to have reached the level for the coolant after 6 liters ? how do i get the other 4 in!?

Almost there, cheers!

Post Mon Jul 23, 2012 8:14 pm

You might find this helpful. http://www.e30zone.net/e30zonewiki/index.php/Cooling