DIY Coolant drain and flush, RS4/S4 (4.2L)

[frmomiller]

After some searching, and just piecing together a procedure, I thought I'd post a DIY on changing the coolant on an RS4/S4 (with the 4.2L V8).
Parts needed:
- Audi G012 Coolant, 2 gallons. Don't waste your time with Autozone (any cheap car parts), Napa (theirs is more $ money the Audi), or Carquest.
- Distilled water, I used up 6 gallons
- 2 5gallon pales
Tools,
- metric allen wrench and a short phillips screw driver

Procedure.
1. put the car on jack stands (or ramps, but you should have the car level).
2. take off the front underbelly plastic pan
3. on the bottom, near the nose, are 2 bleed drain plugs. One is on the bottom front of the engine, on a metal coolant line. It takes an allen wrench. The other is nearer to the driver side on the coolant thermostat (its black and round and has a flex black coolant line running to it), and is a plastic round drain plug with a phillips head. Take both off (don't loose the gaskets, copper ring on the allen plug, rubber on the phillips plug), and have the 2 pales ready.
4. take off the coolant reservoir cap and watch about 7L of coolant mix come out. Yes, this is a 12L in the 4.2L engines. Therefore, flushing is needed in step 6.
5. put the 2 plugs back on.
6. Flushing: fill reservoir with distilled water. You can try and pump upper reservoir hose with your hand to help it flow some; when it stops gurgling, run car, heat on hi, for few minutes, keeping adding distilled water as needed. I did this with the reservoir cap off. Drain this coolant water mix out (back to step 3). Repeat this 2 times, or as many times as you want. I'd say at least once. Use best judgement at disposal of the old coolant, or water/coolant mix.
7. Filling: now to put the 50/50 mix in (or whatever you need). Just follow the flushing above to fill. Considering more water was added to the system, you could probably go with a slightly higher coolant to distilled water ratio. I'd say use your best judgement.
Hope this helps. If anyone objects or has some other ideas, please feel free to add.

[new2s5]

Are one of the two drains (mentioned above) a block drain? Thanks for the input frmomiller.

[ColtS5]

Yes, the metal is basically draining the block, the plastic the radiator.

[deekim781]

How did you bleed it?


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