Cooling flush....

[Will16V]

Gonna attempt to flush out the old coolant in my car tommorrow, and replace with some nice new renault stuff. Ive looked in the haynes manual, and seems quite easy, but has anyone done this b4 on their 16v?

Anything to be careful of, or might need replacing at the same time?

Any help much apreciated,

Will.

 

[damianshaker]

I did this a couple of weeks ago and some guy from TorsionTuning or something like that pointed me in the right direction.

In the haynes manual it says there is a coolant bleed screw somewhere on the back of the block but i couldnt find it. Dont know if this is the right way to do it but it worked for me. I disconnected the top hose from the expansion tank (the thinnest hose) and pointed it down behind the manifold to the floor. I then loosened the radiator bleed plug. Start the engine and get it to normal operating temperature and warm water should start to trickle out of the top hose and down the back of the manifold. I then just kept pouring clean warm tapwater into the expansion tank until the water coming out of the top hose was nice and clear. I then topped up with the right amount of anti freeze. To get rid of any trapped air bubbles I covered up the nipple where the top hose was disconnected and blew into the expansion tank to force any air out through the radiator bleed plug. Then re connect the top hose and put the expansion tank lid back on. Let the engine run for a while and all the remaining air bubbles should have returned to the expansion tank. Unscrew the lid and again, and that hissing you hear should be the remaining air bubbles. Check that everything is nice and tight and with no signs of any leaking water and away you go.

 

[steve_rt]

never heard of this mthod before, sounds much easier - do you keep the engine running while you pour the water into the expansion tank?

 

[Will16V]

I never thought of doing it that way either.....anyway, dosent seem 2 hard, i thought you just drained it all out when cold then blast a load of cold water through the system with a hose pipe till its clear....

 

[Flying Scotsman]

damianshaker, never heard of this method before. Sounds a dodgy method to me. On past cars I have normally removed the drain plug or bottom hose on the radiator (engine cold/off!) and let it drain out. Then flush water through with a hose (for several minues) in both directions to try and remove an sediment from the radiator and block. Lastly and more importantly filled it up again with at least 30% Etylene Glycol anti-freeze. Then run the engine with heaters full on and expansioncap off till hot to bleed air out of system (some have bleed valve on top hose). There are also flushing additives on the market you can use in the old water which you run in the engine for a while to loosen crap before you drain the coolant.

If you have any aluminium in contact with the coolant (eg. head, manifold etc) you should use 50% anti-freeze. This helps to stop freezing in winter, improves cooling in Summer and reduces internal corrosion/sediment.

So, how do you get the anti-freeze in the system to the correct concentration with your method?

 

[BenR]

odd.....

Just undo every pipe, let it all fall out and refill...keep tha cap off the rad whist runnig up to normal temp, and any bubbles will tricle out.......fill with a mixture of antifreeze and water....then havea short drive, let it cool and check the level, top up if needed..

 

[Leigh]

Yer its ok to just remove that top pipe from the rad !! Then if you have got a hose pipe insert it into the expansion tank and flush the whole system out. The pressure from the hose pipe will loosen any debris in the whole system. Then just refill with coolant.

I do it about every six months and it works a treat !! Lovely clear flowing coolant.