What is best way to flush oil from coolant system please

[tmmv1]

Hi
I recently had a head gasket change because there was oil getting into my coolant but now i have oil left in my coolant system.
What is the best way to flush the remaining oil residue from the coolant system please?

[Stickyfinger]

Do NOT use Dishwashing detergent, they have high salt levels and the alkalinity attacks Aluminium.

Many recommend bleach (1/4 pint) and two hot drain/refils then New Coolant mix. Take care of the pressure cap as you do not want it going "Old Faithful" on you.

[white exec]

No DIY brews for this job. Too great a risk of contamination and/or damage.

Get hold of a can (or two) of this, which is designed to do just that job:
LiquiMoly - Radiator Cleaner
300ml can
Art-Nr. 2506

Removes calc, oil, grease, etc from complete cooling system.
Follow the instructions.
Afterwards, flush out copiously with water, and then use ONLY distilled/demineralised water if any is needed.

Have used this successfully on my 2.5 XM after the entire cooling system was filled with engine oil. Leaves system spotless.

[Lighty]

Forte sell a cooling system bio degreaser, it's specifically for this job, always keep a couple of bottles in stock.

[elma]

I'd use a hose and some of that flush already recommended. I've had a lot of success flushing out engine blocks and radiators with a hosepipe.
My method is to remove all the hoses then flush the radiator and block for a long time in both directions. I tend to take the hoses indoors and clean them in the sink with a bottle brush and degreaser. Then reassemble, refill with the radiator degreaser, run until hot. Change the coolant a few times with just water and get it hot between changes. Then put fresh coolant on the last change. The heaters seem to gain 20 degrees after a good flush on my old cars, does them a lot of good I think.

[white exec]

The LiquiMoly product above makes light of the need for repeated flushing. It really does work well, and avoids having to dismantle.
From memory, 1 x 300ml can treats 10 litres of system - but check this out on their website.