Flushing The Cooling System

[Muzzie 0]

What's the best/most effective way of flushing a cooling system out. I've got the pump out of the block and would like to flush it out to get rid of any small bits of metal there may be in there, although i can't see nor feel any. And it probably won't do it any harm.

[OLLIE 26]

with the pump on the block i undo at the pump end the hose that goes from the bottom of the radiator to the pump and aim it to the ground then use a hose and pump water through from the reservior or the reservior hose if you want to take it off and clean it.

there is also a bleed/overflow valve of some kind that has to be undone i cant remember exact details .. but you get the gist.

[Steve K-B 51]

Also, i cant remeber what the e30 water heater hoses are like, but flush out the heater while your at it.

[ducatiss 1]

Tip in some flushing compound into your cooling system and drive around for half an hour or so. make sure you turn your heater up to full to open the valve before turning off the engine. Wait till untill your engine cools a little then undo the bottom hose to your radiator and let it drain. There should also be a drain screw on the block (underneath the exhaust manifold if I remember correctly) thats a complete arse to get at but if you can undo that as well (you may need a new sealing washer). Disconnect your top radiator hose and run a garden hose through it until all the water running out is clear. The do all your hoses up again (being careful not to over tighten the clamps here) Mix up a 50/50 brew of antifreeze and water and fill up the expansion tank. Then you can open up your bleed screw (on top of the thermostat housing where all the hoses joing the at the front of the engine) a few turns. It takes an 8mm spanner. Put some more or your brew in and keep filling until it starts coming out the bleed screw. You may have to give the top hose a bit of a sqeeze to get the water through the system. Close the bleed screw and start the engine and allow it to get up to operating temp. Open the bleed screw again and (keeping the expansion tank at at least the min mark, bleed the system until no more air bubbles come out) Check for leaks round the hoses etc and go for a drive. Once back allow the car to cool then check the collant level and adjust if necessary. - Thats what I did anyway and it worked for me. Hope this helps.

[Muzzie 0]

Well hopefully lol

I've flushed it out and put antifreeze in it, and taken it for a good 120k run and it looks to be fine now with the new pump etc.

Now I just gotta sell it