[Kingof4rings]

My 2016 with 88k has no heat, not even slightly warm air. I looked at other threads about the same issue and thought the heater control valve may be the culprit so I pulled the fender liner tonight. The valve looked fine but with the car at operating temp there was no coolant going to or from the valve.
There are no visible coolant leaks, no overheating issues, and the coolant reservoir is at the bottom line when hot.
My next step was going to be topping of coolant and seeing if I can get any air bubbles out and if that doesn't yield results maybe flushing the system. Any input would be appreciated!

 

[New2Tregs]

Hello and welcome to the forums.
If the heater control valve for the heater core is stuck in the closed position the coolant might stay cool at both sides due to the coolant not being able to flow.
There was a member on here who realized theirs was stuck closed when they bypassed that valve with a piece of hose and got heat back. I'm not sure how mechanically inclined you are and I'm not saying it's going to fix the problem but it's a good test.
If you do flush the coolant, which VW says should be done every 30K miles or 2 years, it should be refilled using a vacuum type of tool so as to not get any trapped air.

 

[Kingof4rings]

I saw that thread but I thought I misread it. I assumed a blockage at the valve wouldn't affect the coolant flow from the engine but maybe it formed some sort of air pocket?
That's good to know about the vacuum tool to flush, I don't have shop air so I might take it to a shop to do that first.
The car is new to me and the coolant looks fine but I doubt was done every 2 years.

 

[volkswagens-for-life]

Ac work good? Could be blend door

 

[New2Tregs]

Ac work good? Could be blend door

If it were a blend door problem wouldn't the OP still have heated coolant in the hoses on each side of the heater core control valve?

 

[Kingof4rings]

Ac work good? Could be blend door

Yes the AC works no issue.

 

[volkswagens-for-life]

If it were a blend door problem wouldn't the OP still have heated coolant in the hoses on each side of the heater core control valve?

Good catch. You're right

 

[New2Tregs]

I saw that thread but I thought I misread it. I assumed a blockage at the valve wouldn't affect the coolant flow from the engine but maybe it formed some sort of air pocket?
That's good to know about the vacuum tool to flush, I don't have shop air so I might take it to a shop to do that first.
The car is new to me and the coolant looks fine but I doubt was done every 2 years.

I think if there's a blockage or the valve is stuck closed it basically becomes dead headed and the coolant doesn't flow. A stuck air pocket might do that but I thought these vehicles would eventually burp themselves if the heat is turned to max and idle is at 2k for a few minutes. Definitely make sure the coolant in the reservoir is at the max line prior.

 

[volkswagens-for-life]

If the coolant system has been cracked recently I can almost guarantee it needs burped. Huge pita on these

 

[Kingof4rings]

If the coolant system has been cracked recently I can almost guarantee it needs burped. Huge pita on these

Well I had the dealership flush the coolant and still no luck. I am sort of stumped now.

 

[volkswagens-for-life]

Well I had the dealership flush the coolant and still no luck. I am sort of stumped now.

Did they flush before or after these issues started

 

[New2Tregs]

Well I had the dealership flush the coolant and still no luck. I am sort of stumped now.

Something is stopping the coolant flow to/through the heater core. If you're going to diagnose this yourself you're going to have to get the vehicle to temp and check all coolant hoses to see which ones are warm/hot and which ones are not, aside from the two you already know are not.
I know on my '11 there are two other "heater/coolant" control valves. I believe they are vacuum operated. They are #23 in the picture below which is for 2011-2017's. One I know for sure is on the drivers side of the engine towards the back. The other is on the passenger side but I'm not sure where exactly as a shop changed this one and I didn't see it.
You'd have to see if the hoses on each side of them are warm/hot and also verify if there is vacuum on the line attached to them.

 

[SaVAGeSoot]

You're still in warranty. Is this not something covered under warranty?

 

[Klaudio Sharra]

I had the same problem on my '11 Touareg 3.0 TDI and sent my car to the service shop. They only charged me $50 (Services are cheap in Albania) and the reason of that was blocked valves and water hoes( I dont exactly know which ones). Now it blows flaming hot air after that little fix.

 

[Kingof4rings]

So the issue is solved. After the dealer flushed the coolant I had them diagnose it. They came back and said it was the heater control valve. I was quoted just over $1000. So of course I declined that and ate the $140 diagnostic fee. I ordered the part through another dealer for around $150 and got around to installing it tonight. I was pretty worried about dumping coolant everywhere even though it didnt seem like coolant was flowing to the valve. I took off the engine side first and quickly connected to the new valve then heater core side. I probably lost about 3-4oz of coolant in total. I buttoned it back up and the heat works great. My tiny little brain still doesn't understand why a bad valve would cause the hose that goes TO the valve to not heat up. It's an easy job and paying the diag fee to the stealership made me confident that I wasn't just throwing parts that the problem. Thanks to everyone for your input and help!

 

[volkswagens-for-life]

Awesome follow-up thanks !

 

[TommiT]

Well done.

 

[New2Tregs]

So the issue is solved. After the dealer flushed the coolant I had them diagnose it. They came back and said it was the heater control valve. I was quoted just over $1000. So of course I declined that and ate the $140 diagnostic fee. I ordered the part through another dealer for around $150 and got around to installing it tonight. I was pretty worried about dumping coolant everywhere even though it didnt seem like coolant was flowing to the valve. I took off the engine side first and quickly connected to the new valve then heater core side. I probably lost about 3-4oz of coolant in total. I buttoned it back up and the heat works great. My tiny little brain still doesn't understand why a bad valve would cause the hose that goes TO the valve to not heat up. It's an easy job and paying the diag fee to the stealership made me confident that I wasn't just throwing parts that the problem. Thanks to everyone for your input and help!

Awesome! Glad you got it sorted and saved some $$$.
So it was the heater control valve in the fender liner?
As far as why the coolant was not hot on both sides I think it's what I mentioned in post #8. If the valve is closed then there's no coolant flow and the coolant that's there just stays cold. Basically dead headed.

 

[Kingof4rings]

Yes , that's the one.
You were right! I must be picturing it wrong but I was thinking that coolant would be flowing from the motor and stop at the valve when its closed but the valve must send a signal to something else upstream in the coolant system that allows coolant to flow. If I get bored this weekend I'm going to do an autopsy on the old valve to see if I can find out what the issue was.