Take the thermostat out?

Want to flush though the block or not :p to be fair I may have mis-read the original message as was having a cheeky look at work (phones are banned in workshop) I thought he meant the HG had gone and got oil/water mix. Either way if you wanted to flush though the engine correctly is easier to remove the stat or housing which is easy on the ZS than it is to remove the water pump :thumbsup:

Its worth noting catch the coolant and dispose of it properly.

Its toxic to cats and dogs and cats will lick it beacuse to them it smells and tastes sweet

The conversation has lead to a suggestion to empty the system and refill with clean water, and drive the car to run it through to get the thermostat to open and fully flush the system and then do this several times.

Popping the thermostat out on the K4 is reasonably straight forward and the option I would take.

I agree this is the best option but if you are not to good with cars it is a bit tricky to do the stat with the intake on. Plus bear in mind you might find any of the o rings split or expand with you remove it all if you don't have spares might run into trouble

Personally, I go for the 'drain it and fill with water' approach - and add some rad flush too.
Run it for 10-15 miles, then drop it all back out and fill with proper coolant. :)