AllroadMatt

So I am losing coolant and I can’t figure out were. Right now I am filling the tank every morning before I drive, switch between coolant and water so that I keep my 50/50 mix. After 30min. to 2hrs. of driving I’ll start getting the warning that my coolant level is low, and the tank will be completely empty. I have run numerous pressure tests and it passes every single time. I have also just had the car sit for about an hour with the engine running and lost no fluid. It only happens when I drive. I have even replaced my tank and cap more then once to make sure it wasn’t either of them.

Any Ideas?

Thanks.

4ringking

Have you performed a visual inspection from the bottom of the vehicle?
If the correct G12 or G13 is being used in the cooling system, you should find some pink crusty build-up where ever the leak is. Green or Dex-Cool is a NO no in these vehicles....

Is you check engine light on?

AllroadMatt

I haven't look under the car in awhile but when the problem first appeared I did, and found nothing. I think I have only driven the car maybe 8 times since January. Ya I'm using g12.

GTA_Driver

Well, you've got to get under and see what's happening. Best to take the underbelly pan off and then see where coolant drips are occurring. Lifting the car and examining the bottom is also a good idea.

Check from the engine bay, look at each side, rear and front of the engine, use a good light to see if there are any caked white powder (coolant deposits).

jhart2.7t

My last coolant leak was a heater core hose that was split near the block. No one could diagnose with a visual. Only leakes while/after it had been driven. Second pressure test showed leak.
The shop had to remove a lot of stuff to replace the dealer only item. I believe I paid less then $400 for the repair.

jhart2.7t

Also, don't rule out the secondary water pump. A very common failure. Mine was bone dry thankfully.

4ringking

I'll twice that!

AllroadMatt

Thanks for all the advice, looks like I have some work to do. I will update when I find out.

09mehashaw

If you do not seat the seal correctly you can easily get a leak at the Engine Coolant Temperature Sensor and at the Afterrun Coolant Pump Switch.
The ECT is on the passenger side of the vehicle, behind the engine. it has a small loom of around 3 wires coming from it.
The After run Switch is in a similar position except on the drivers side.

Kummys

Hi did anyone manage to cure the coolant low problem on the Audi q7 if so what was the issue I've got an Audi q7 2012 and have got same issue losing coolant every few days I've changed the water pump but still the same issue coolant low