Radiator flush & fill

[NORTY]

A friend of mine drove to Texas in July this year. His car overheated in Arizona. He drives a 2006 A6. (Non-Z51.)

The A/C disabled until the engine recoverd. He never uses "S" Mode or the paddles. He just puts it in "D" and drives! Anyway, he asked me where the radiator drain valve is. I told him to remove the bottom hose, but had concerns about the trans cooler line. So, here's my question~

1. Is there a transmission line conected to the radiator in a NON Z51 car?

2. Is removing the bottom coolant hose the proper procedure to drain the coolant?

3. I presume the system can be refilled with DEXCOOL product?

4. Would one refill the system via the over flow tank?

5. Is there a air bleed valve on the water pump housing? Or, do we need to "prime" the H2O pump?

I don't have an automatic in my Z or I'd go look myself. Thanks to anyone who can help

Also, is there a "tutorial" on this site somewhere? I looked but found nothing for C6.

[froggy47]

I need to do this on my c5z also. Any tips?

[LLC5]

C5 has a drain on the bottom right of the radiator that you turn to open and close about 1/2 of a turn, I haven't done a C6 to be sure on that model. I would definately use dexcool for coolant unless someone else has switched the coolant to a different type. C5 you do fill through the surge tank, run it to get it hot let it cool multiple times checking the level cold on the surge tank making sure the vehicle is on a flat level surface. I do not know of any bleed valve by the water pump as I have never needed one. Good luck with it.

[froggy47]

Originally Posted by LLC5

C5 has a drain on the bottom right of the radiator that you turn to open and close about 1/2 of a turn, I haven't done a C6 to be sure on that model. I would definately use dexcool for coolant unless someone else has switched the coolant to a different type. C5 you do fill through the surge tank, run it to get it hot let it cool multiple times checking the level cold on the surge tank making sure the vehicle is on a flat level surface. I do not know of any bleed valve by the water pump as I have never needed one. Good luck with it.

Thanks!

:)

[NORTY]

So, nobody has ever changed the coolant in their C6? Anyone?

[ToolGuy]

Sounds like the issue is not just the coolant to cause it to overheat while driving, I presume a far distance too... The fans must be sure they are turning on, the radiator fins are not clogged and all the proper shields and air dams are in place. Water pump and any exterior leaks checked for too.

Once you open the system to drain the coolant, I would put a new GM thermostat in and check the hoses. There could be another issue besides the thermostat, which it may not be at all, that caused it to overheat.

On my C5:

There is no bleeder screw, you take off the throttle body coolant hose and air bleeds out of it. re-attach when coolant start to come out of the hose.
You refill through the overflow bottle as there's no cap on the radiator. I assume C6 to be the same, but you know what happens when you assume. Your friend shouls be able to look under the hood for this.