chocolate_o_brian

iTrader: (22)

ive done a search and couldnt come up with a method of replacing the engine coolant. i want to do this for piece of mind incase the previous owners have topped up with water not proper coolant. but i dont know how to replace it all. the engine is a 93 wrx one and has the yellow coolant cap and overflow piece on the bottom right of the engine, between the battery and headlight.

can someone explain how i "bleed?" or drain the coolant and then refill with a fresh... oh and whats best to use for my engine.

(wasnt sure whether to post here or gen tech)

thanx in advance guys

The Rig

iTrader: (13)

i usually let the car get slightly warm,enough for thermostat to open, then i remove bottom hose off of rad and let it pour away, i then, for about 10 seconds,sometimes turn engine over or let ti run for 10 seconds to pump remainder of water out of block.

then,replace hose and then start engine again and SLOWLY pour in water/antifreeze of your choice, not sure if a special antifreeze is needed for the block or not,some1 will know.

then walla,done.

but im sure the scoob is so different to any other car thats all wrong and will be condemned !!

cheers......

olliecampbell

iTrader: (3)

Basically as above, the drain plug is bottom left (as your looking at the engine) let it drain. Mine took quite a while to do (it slowly dribbles out but does it for ages).

Not sure i would want to run it for too long without any water, but thats my choice i suppose.

Then fill 50/50 with decent antifreeze. Job done. Fill it slowly though, run it for a bit to get rid of trapped air (a few hours or a day commuting etc) then check the levels again.

rmtypeR

I did mine recently, and the problem I had was that after re-filling it to the brim through the metal tank (the one on the left if stood looking at the engine from in front of the car), the expansion tank (plastic one on the right) wasn't filling, even after about an hour of gently topping up then squeezing the hoses. So I asked about it here, and got a few useful pointers...

http://forums.sidc.co.uk/forums/701188/ShowPost.aspx

In the end, I manually filled the expansion tank so the level was between L and F, and everything seems to be working fine!

The only thing I'd add is that I drained it by removing the lower hose (for at least an hour), but after re-filling it's clear that I didn't get all the old coolant out, as the colour changed where the old and new mixed a bit. So next time I'd try using the drain plug instead (which I didn't know existed back then!)

Shark Man

It's abit **** this, but works and doesn't get air lock. I do it with most cars..except I can usually fill most cars alot quicker than scoobs which take an age.


Run engine until radiator gets hot (thermostat open)
Put heater on full heat (iginition ON and blowers on if it has auto climate control)
Engine OFF
Remove header tank cap SLOWLY with a rag to prevent scalding (by alternator) and drain plug at the bottom left of the radiator (use a rag or gloves if you don't have a resistance to hot water - watch out for the exhaust headers! )...remove it completely otherwise you'll be there 'til winter (don't drop it on the undertray ) Alternatively, remove the bottom rad hose .

If the coolant is gunky and cloudy, remove bottom and top rad hoses, flush rad through with the hose pipe, do the same with the header tank. A further step if it is really bad is to remove the heater matix hoses and flush through these with the hosepipe too (but not needed unless the car has been neglected) and remove and flush out the expansion/overflow tank (yellow lid in the wing by the battery).

Refit all hoses and drain plug,
Pre mix 50:50 water and antifreeze, use any antifreeze as long as says its safe for alloy engines. Can use distilled instaed of tap water if you want to be really ****
FILL SLOWELY and keep header tank half to three quarters full, giving the rad hoses a squeeze every now and again.

Fill enpansion tank (tank with yellow lid by battery to the level and put the lid on)

Leave header cap OFF (tank by alternator), and start engine, run engine add coolant to keep header half to three quarters full. Keep heater on full heat, blowers on 1 or 2.

Run until thermostat opens (radiator gets hot) Don't worry if a little coolant overflows, Give teh engine a few blips to help push any air out. If it starts gushing out put cap on and switch off and let it settle. leave it cool for around 30mins and recheck header tank and top up to full if needed. Recheck the overflow/expansion tank too.

Next time you go for a drive, check before starting journey, and recheck afterwards when the engine has cooled down completely.