Coolant Change

[jamieherd 0]

Guys

Looking to do a full coolant change at the weekend as my coolant is a getting bit dirty.

Was gonna start by letting the engine warm up to normal operating temperature so the stat opens then undo bottom rad hose. Will this release all of the coolant in the block and radiator?

Does anyone know of a better or correct way of doing this?

I was also going to use holts speedflush? Is this any good.

[Guest The Butcher]

Wouldn't bother with the flush mate, tbh...i wouldn't even heat the engine up..take of bottom rad pipe..take of top rad pipe also..will drain rad quicker..

[thegoth 5]

certainly don't heat it. it'll presurize the system and you risk being scalded

[jamieherd 0]

So by unhooking the top and bottom rad hoses will this drain all of the coolant from the system including the block? Or am i gonna have to take stat off to do this?

[Guest The Butcher]

drain it, fill it with water then drain it again..should act as a flush also

[shail 0]

Done it a few times taking rad hoses off. Works ok, but you'll never get all of the coolant out, so fill with water, run, empty, as mentioned above.

There is a drain plug on the underside of the black plastic 'crack pipe' that runs along the front of the engine, which is where officially you should drain from. But its a bit of a pain to see / get to. You may also need a new drain plug & washer (available from VW for a couple of quid)

[Pearsy47 1]

what about air locks cos i changed all my pipes now its sounds like all the water is rushing out of the heater matrix it does that a couple of time when i you switch off and also you the the second water pump which stays on once you turn the motor off that sommetimes goes mad !!!