adobian

Thanks guys, for taking the time to answer. I don't think I want to call Audi of America.

So sad to read about this. And yes the engine is pricy.

So the head can be taken out to machine shop for milling/resurfacing?

adobian

The grill Infront of the radiator is stuck on (open). Autozone scan this code, it says active grill stuck on.

​​​​​​I Inspected and verify the grill is open. My friend told me to buy the motor and he will replace it for me. He said it will solve the problem. I don't believe it.

I tried to tell him and he got mad and said he doesn't want to help anymore.

I said if it's stuck open then the fan blowing through the radiator will do the job.

Coolant level light is red all the time. I think it needs a new reservoir because the coolant level sensor s bad. Correct? Could this sensor problem cause the grill to be stuck on automatically?

I mean right now, driving under 1000 RPM (20 MPH) with the fan on, the temp remains in range. No sign of leaks.

I derived from this.
1/ coolant is still.in the engine block.
2/ coolant may not flow correctly but still connect to the radiator somehow for it to be cooled by the radiator fan.
3/ heater core could be clogged. (Very likely here cause I lost heat all of a sudden on the highway)
4/ Thermostat could be stuck close or open.

What would happen if the thermostat is stuck open? Engine runs rich all the times? And would that cause overheating?

5/ Radiator could be clogged.




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Dtomasi

Why do you keep speculating? Sorry but If the engine overheated multiple times as you say and your mechanic found oil in the coolant there's probably coolant in the oil, the engine is done! Everything else doesn't matter. It's time to replace the engine or part the car out.

adobian

He did a head gasket job.

This is the second time and it's relating to the flow of coolant. Clogging due to stop leak or possibly failed Thermostat

retom

I fully agree with Dtomasi. There's nothing to speculate. It's just a waste of your time, nerves and money. The car cooling system is not difficult to diagnose and repair. From what you write you have several problems there: engine overheating, constantly open radiator shutter and a low fluid level warning.I am assuming that the coolant level is OK. It's possible that the thermostat is stuck intermittently. A constantly open radiator shutter is certainly not the reason for engine overheating.
First of all, check the coolant level in the expansion tank. If it is OK, it means that the level sensor is damaged and should be replaced together with the tank. Coolant level should be between min and max. Also, a faulty coolant level sensor is not the cause of engine overheating.
A damaged radiator shutter motor is a common problem in older Q7s. Search this forum because some people managed to fix it at Audi's expense in cars out of warranty.
My advice if I may: don't speculate, don't experiment and don't take unnecessary risks because you can only make more damages and have much higher costs. Acting blindly, without the proper knowledge and tools with the help of friends may not be also the best solution. With our best good will also our theoretical advices based on your descriptions wont help much. Find a good mechanic who will deal with the problem, diagnose faults, replace damaged elements, flush the entire system and bleed it properly.
A separate story is, as Dtomasi wrote, possible damage of the engine caused by a damaged head gasket. I would not be so fast with the whole engine swap as it is expensive and very complex but for sure your engine after head gasket replacement also deserves a fair and detailed inspection.