2007 A8 right side vents blow scolding hot
09-23-2014, 11:37 PM
#1
2007 A8 right side vents blow scolding hot
2007 A8 4.2. Wife complained of a sudden temperature change in her vents (passenger side) which suddenly started blowing hot in the Mojave desert of all places. Meanwhile the driver's side was still blowing cold.
We stopped so that I could take a look and as soon as we stopped it started blowing cold again. So we thought maybe it was just a temporary issue. I go to leave the parking lot and as soon as I give it gas the passenger side vents go hot again and they're not going hot as in they are pulling in outside air; they're going hot like they are on full heat. It was hot enough that it was uncomfortable to hold my hand in front of the vent.
Who wants to play!?
We stopped so that I could take a look and as soon as we stopped it started blowing cold again. So we thought maybe it was just a temporary issue. I go to leave the parking lot and as soon as I give it gas the passenger side vents go hot again and they're not going hot as in they are pulling in outside air; they're going hot like they are on full heat. It was hot enough that it was uncomfortable to hold my hand in front of the vent.
Who wants to play!?
09-24-2014, 05:32 AM
#2
AudiWorld Super User
A diagnostics scan will indicate which flap is sticking. Due to a cracked part or defective stepper motor or control module. Flap/stepper motor replacement is a huge job.
09-24-2014, 08:43 AM
#4
Can you elaborate on the heater coolant valve?
I don't believe it is a flap or a bad stepper motor as it works when you are parked and there is nothing about being parked that should affect the operation of either of those components.
It really seems like something that relies on vacuum suddenly lost it and only gets it during idle.
I don't believe it is a flap or a bad stepper motor as it works when you are parked and there is nothing about being parked that should affect the operation of either of those components.
It really seems like something that relies on vacuum suddenly lost it and only gets it during idle.
09-24-2014, 08:53 AM
#5
AudiWorld Super User
Coolant valve...
is under the plenum cover on the passenger side. Has a bunch of hoses that connect to it, and a few electrical connectors. Fundamentally one set of hoses are for each side of the car. Not much documentation about it. It has solenoids that regulate the hot water flow to the left and right sides. If those fail or stick open, you then have hot water flowing to either the drivers or passenger side heater core. It still needs air blowing over the core, but the water control starts from here.
The valve is not monitored/testable via VAG COM if I remember right, and the solenoids are the pulse/variable type so if you apply normal current to them they get fried. If you suspect the valve, about all you can do is either swap it out, or pull it out and very carefully disassemble to clean. It's a big bucks part--a grand type thing. Found on EBay once in a while, but you have to get the right specific one--used back to the D2 IIRC. I had insufficient interior cooling at one point (never super hot air blowing; just a musty somewhat humid feel) and suspected the valve so pulled it out and successfully took apart. Mine was totally clean. Turned out in my case it was simply the AC refrigerant charge. It unbolts with a few screws, plus on a W12 moving one of the ECU's aside. There was a hidden connector underneath to be careful of and was kind of a blind reach to unfasten.
The valve is not monitored/testable via VAG COM if I remember right, and the solenoids are the pulse/variable type so if you apply normal current to them they get fried. If you suspect the valve, about all you can do is either swap it out, or pull it out and very carefully disassemble to clean. It's a big bucks part--a grand type thing. Found on EBay once in a while, but you have to get the right specific one--used back to the D2 IIRC. I had insufficient interior cooling at one point (never super hot air blowing; just a musty somewhat humid feel) and suspected the valve so pulled it out and successfully took apart. Mine was totally clean. Turned out in my case it was simply the AC refrigerant charge. It unbolts with a few screws, plus on a W12 moving one of the ECU's aside. There was a hidden connector underneath to be careful of and was kind of a blind reach to unfasten.
Last edited by MP4.2+6.0; 09-24-2014 at 08:58 AM.
09-24-2014, 09:54 AM
#6
is under the plenum cover on the passenger side. Has a bunch of hoses that connect to it, and a few electrical connectors. Fundamentally one set of hoses are for each side of the car. Not much documentation about it. It has solenoids that regulate the hot water flow to the left and right sides. If those fail or stick open, you then have hot water flowing to either the drivers or passenger side heater core. It still needs air blowing over the core, but the water control starts from here.
The valve is not monitored/testable via VAG COM if I remember right, and the solenoids are the pulse/variable type so if you apply normal current to them they get fried. If you suspect the valve, about all you can do is either swap it out, or pull it out and very carefully disassemble to clean. It's a big bucks part--a grand type thing. Found on EBay once in a while, but you have to get the right specific one--used back to the D2 IIRC. I had insufficient interior cooling at one point (never super hot air blowing; just a musty somewhat humid feel) and suspected the valve so pulled it out and successfully took apart. Mine was totally clean. Turned out in my case it was simply the AC refrigerant charge. It unbolts with a few screws, plus on a W12 moving one of the ECU's aside. There was a hidden connector underneath to be careful of and was kind of a blind reach to unfasten.
The valve is not monitored/testable via VAG COM if I remember right, and the solenoids are the pulse/variable type so if you apply normal current to them they get fried. If you suspect the valve, about all you can do is either swap it out, or pull it out and very carefully disassemble to clean. It's a big bucks part--a grand type thing. Found on EBay once in a while, but you have to get the right specific one--used back to the D2 IIRC. I had insufficient interior cooling at one point (never super hot air blowing; just a musty somewhat humid feel) and suspected the valve so pulled it out and successfully took apart. Mine was totally clean. Turned out in my case it was simply the AC refrigerant charge. It unbolts with a few screws, plus on a W12 moving one of the ECU's aside. There was a hidden connector underneath to be careful of and was kind of a blind reach to unfasten.
Either way that's it. I'm selling the car at a loss. I have absolutely never owned a car this bad. This is my second D3 A8. I can afford the car and it's maintenance and I bought it fully knowing that it would experience the occasional hiccup that would cost me some money. What ensued was worse than I could have ever imagined.
In 9 months of ownership 3 injectors have failed, a low pressure fuel pump, a high pressure fuel pump, oil separator, oil pressure sensor, several vacuum/ PCV hoses have simply broken because Audi chooses to use a hard plastic that turns to dust, it's starts slowly, the AC now blows hot on one side and just a couple weeks ago the flaps in the intake jammed necessitating a $1500 intake manifold. And this is just the stuff I can remember off hand.
I know things break but this is just a choice of poor quality materials and it's beyond frustrating. I've been pining over a D4 to replaced my BMW and despite the issues I've had with my D3 I kept telling myself the D4 would be under warranty but now I just can't bring myself to give this company any of my money. Someone else can roll with this turd. I'll be shopping for a Model S.
Thanks for your help.
09-24-2014, 10:11 AM
#7
AudiWorld Super User
Jut sticking to the valve part (and not the whole Audi experience subject),
I don't know the V8 FSI motors and aux. components that well. But at least on a W12 and I think an S8, there is also an auxiliary electrical water pump that has a dual purpose after run cool down function, but also a low RPM supplementary water flow function. Thus on my W12, if it was low RPM only that was really noticeable, I would also be looking at that auxiliary water pump and how it is switched both electrically and valve wise. There is an obscure one way/check valve or two in those systems that deals with keeping the A/C panel from freezing up when the car is shut down, yet allowing the after run cooling function. Don't know if they carried over a similar set up to the later 4.2 FSI's. I can guess it may be in the D4's given the turbos and likely after run systems.
Trending Topics
09-24-2014, 11:26 AM
#8
AudiWorld Member
Yeah I did a bit of research on it and it certainly seems like that could be it but the fact that it cools when it's stopped is particularly confusing to me unless the valve is just weak and the higher fluid flow from higher rpm is overpowering the valve.
Either way that's it. I'm selling the car at a loss. I have absolutely never owned a car this bad. This is my second D3 A8. I can afford the car and it's maintenance and I bought it fully knowing that it would experience the occasional hiccup that would cost me some money. What ensued was worse than I could have ever imagined.
In 9 months of ownership 3 injectors have failed, a low pressure fuel pump, a high pressure fuel pump, oil separator, oil pressure sensor, several vacuum/ PCV hoses have simply broken because Audi chooses to use a hard plastic that turns to dust, it's starts slowly, the AC now blows hot on one side and just a couple weeks ago the flaps in the intake jammed necessitating a $1500 intake manifold. And this is just the stuff I can remember off hand.
I know things break but this is just a choice of poor quality materials and it's beyond frustrating. I've been pining over a D4 to replaced my BMW and despite the issues I've had with my D3 I kept telling myself the D4 would be under warranty but now I just can't bring myself to give this company any of my money. Someone else can roll with this turd. I'll be shopping for a Model S.
Thanks for your help.
Either way that's it. I'm selling the car at a loss. I have absolutely never owned a car this bad. This is my second D3 A8. I can afford the car and it's maintenance and I bought it fully knowing that it would experience the occasional hiccup that would cost me some money. What ensued was worse than I could have ever imagined.
In 9 months of ownership 3 injectors have failed, a low pressure fuel pump, a high pressure fuel pump, oil separator, oil pressure sensor, several vacuum/ PCV hoses have simply broken because Audi chooses to use a hard plastic that turns to dust, it's starts slowly, the AC now blows hot on one side and just a couple weeks ago the flaps in the intake jammed necessitating a $1500 intake manifold. And this is just the stuff I can remember off hand.
I know things break but this is just a choice of poor quality materials and it's beyond frustrating. I've been pining over a D4 to replaced my BMW and despite the issues I've had with my D3 I kept telling myself the D4 would be under warranty but now I just can't bring myself to give this company any of my money. Someone else can roll with this turd. I'll be shopping for a Model S.
Thanks for your help.
09-24-2014, 07:44 PM
#9
AudiWorld Senior Member
Also sorry to hear
Yeah I did a bit of research on it and it certainly seems like that could be it but the fact that it cools when it's stopped is particularly confusing to me unless the valve is just weak and the higher fluid flow from higher rpm is overpowering the valve.
Either way that's it. I'm selling the car at a loss. I have absolutely never owned a car this bad. This is my second D3 A8. I can afford the car and it's maintenance and I bought it fully knowing that it would experience the occasional hiccup that would cost me some money. What ensued was worse than I could have ever imagined.
In 9 months of ownership 3 injectors have failed, a low pressure fuel pump, a high pressure fuel pump, oil separator, oil pressure sensor, several vacuum/ PCV hoses have simply broken because Audi chooses to use a hard plastic that turns to dust, it's starts slowly, the AC now blows hot on one side and just a couple weeks ago the flaps in the intake jammed necessitating a $1500 intake manifold. And this is just the stuff I can remember off hand.
I know things break but this is just a choice of poor quality materials and it's beyond frustrating. I've been pining over a D4 to replaced my BMW and despite the issues I've had with my D3 I kept telling myself the D4 would be under warranty but now I just can't bring myself to give this company any of my money. Someone else can roll with this turd. I'll be shopping for a Model S.
Thanks for your help.
Either way that's it. I'm selling the car at a loss. I have absolutely never owned a car this bad. This is my second D3 A8. I can afford the car and it's maintenance and I bought it fully knowing that it would experience the occasional hiccup that would cost me some money. What ensued was worse than I could have ever imagined.
In 9 months of ownership 3 injectors have failed, a low pressure fuel pump, a high pressure fuel pump, oil separator, oil pressure sensor, several vacuum/ PCV hoses have simply broken because Audi chooses to use a hard plastic that turns to dust, it's starts slowly, the AC now blows hot on one side and just a couple weeks ago the flaps in the intake jammed necessitating a $1500 intake manifold. And this is just the stuff I can remember off hand.
I know things break but this is just a choice of poor quality materials and it's beyond frustrating. I've been pining over a D4 to replaced my BMW and despite the issues I've had with my D3 I kept telling myself the D4 would be under warranty but now I just can't bring myself to give this company any of my money. Someone else can roll with this turd. I'll be shopping for a Model S.
Thanks for your help.
I feel your pain. Mine has required more maintenance than my last 10 cars put together. I have as many miles on my 2013 ES300H and my wife's cars are almost as old. None seem to need anything. Just oil changes and gas.
This last weekend the MMI screen stopped opening all the way. Back to the stereo shop to pull the dash to see what screwed up. Extremely poor design.
I am keeping it, but am learning way too much about small issues. Only owned it for 7 months and 6,000 miles. The list of items fixed and/or serviced is LONG. But like the car.
My wife laughs when she sees me working on it. She gets in her Toyota or BMW and drives off. I must be a glutton for punishment.
09-24-2014, 10:00 PM
#10
AudiWorld Super User
When I said "walking wounded" I do mean stay away from
those cars... When they're abused, or born defective just like children, they're never be as good as the pampered and healthy ones.
I can understand the feelings of having a bad cars, but I have never experienced one yet. Yes, cut the loss and move on, but all cars have "walking wounded" ones floating around, the question is how to spot these "walking wounded" cars, it doesn't matter it's Audi, BMW, Lexus, Mercedes or even Toyota or Honda, because if you can't spot them, you may end up with the new brand "walking wounded" one... the horrible story will begin again... insidious... scary
Cheers,
Louis
I can understand the feelings of having a bad cars, but I have never experienced one yet. Yes, cut the loss and move on, but all cars have "walking wounded" ones floating around, the question is how to spot these "walking wounded" cars, it doesn't matter it's Audi, BMW, Lexus, Mercedes or even Toyota or Honda, because if you can't spot them, you may end up with the new brand "walking wounded" one... the horrible story will begin again... insidious... scary
Cheers,
Louis