A/C Takes 8 Minutes to Cool
Thread Starter
Newbie
Joined: Sep 2023
Posts: 13
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2005 E55 AMG
A/C Takes 8 Minutes to Cool
Hi Everyone,
I have been struggling to figure out what is going on with my A/C on the E55.
If the car sits any longer than overnight, then it will take almost exactly 8 minutes to get cold air from the vents.
The strange thing is it's always 8 minutes.
Parked at idle (no airflow) - 8 minutes.
Hit the highway immediately (max airflow) - 8 minutes.
70* ambient temp - 8 minutes.
100* ambient temp - 8 minutes.
I can understand that when the car has not been driven, that the A/C is fighting the existing heat to build up cold air. The weird thing is that it would take the same amount of time regardless of the ambient temp, or vehicle speed.
I have also never been in a car that takes longer than a minute or so to push cold air out of the vents, even in summer time weather.
Once the 8 minute mark has passed, the air stays cold at all times. I don't have any warmer air at idle or anything like that. It's gets cold and stays there.
I also can get in the car after it has sat for a number of hours and get cold air immediately. There is a certain point where it has sat long enough that we are back to the 8 minute wait time.
Is anyone else in a hotter environment who can advise on what their wait time typically is for cold air? I expect that I am not experiencing a normal functioning A/C.
I have been struggling to figure out what is going on with my A/C on the E55.
If the car sits any longer than overnight, then it will take almost exactly 8 minutes to get cold air from the vents.
The strange thing is it's always 8 minutes.
Parked at idle (no airflow) - 8 minutes.
Hit the highway immediately (max airflow) - 8 minutes.
70* ambient temp - 8 minutes.
100* ambient temp - 8 minutes.
I can understand that when the car has not been driven, that the A/C is fighting the existing heat to build up cold air. The weird thing is that it would take the same amount of time regardless of the ambient temp, or vehicle speed.
I have also never been in a car that takes longer than a minute or so to push cold air out of the vents, even in summer time weather.
Once the 8 minute mark has passed, the air stays cold at all times. I don't have any warmer air at idle or anything like that. It's gets cold and stays there.
I also can get in the car after it has sat for a number of hours and get cold air immediately. There is a certain point where it has sat long enough that we are back to the 8 minute wait time.
Is anyone else in a hotter environment who can advise on what their wait time typically is for cold air? I expect that I am not experiencing a normal functioning A/C.
MBWorld Fanatic!
Joined: Jan 2011
Posts: 2,159
Likes: 160
2006 E55
Try replacing the aux battery - when was the last time you changed it? That was my culprit when I noticed the A/C taking time to build cold air, or simply not blowing cold anymore. Not saying that's your issue , but depending on how old your aux battery, could impact electrical components in the car.
MBWorld God!
Joined: Dec 2019
Posts: 32,222
Likes: 6,278
Hi Everyone,
I have been struggling to figure out what is going on with my A/C on the E55.
If the car sits any longer than overnight, then it will take almost exactly 8 minutes to get cold air from the vents.
The strange thing is it's always 8 minutes.
Parked at idle (no airflow) - 8 minutes.
Hit the highway immediately (max airflow) - 8 minutes.
70* ambient temp - 8 minutes.
100* ambient temp - 8 minutes.
I can understand that when the car has not been driven, that the A/C is fighting the existing heat to build up cold air. The weird thing is that it would take the same amount of time regardless of the ambient temp, or vehicle speed.
I have also never been in a car that takes longer than a minute or so to push cold air out of the vents, even in summer time weather.
Once the 8 minute mark has passed, the air stays cold at all times. I don't have any warmer air at idle or anything like that. It's gets cold and stays there.
I also can get in the car after it has sat for a number of hours and get cold air immediately. There is a certain point where it has sat long enough that we are back to the 8 minute wait time.
Is anyone else in a hotter environment who can advise on what their wait time typically is for cold air? I expect that I am not experiencing a normal functioning A/C.
I have been struggling to figure out what is going on with my A/C on the E55.
If the car sits any longer than overnight, then it will take almost exactly 8 minutes to get cold air from the vents.
The strange thing is it's always 8 minutes.
Parked at idle (no airflow) - 8 minutes.
Hit the highway immediately (max airflow) - 8 minutes.
70* ambient temp - 8 minutes.
100* ambient temp - 8 minutes.
I can understand that when the car has not been driven, that the A/C is fighting the existing heat to build up cold air. The weird thing is that it would take the same amount of time regardless of the ambient temp, or vehicle speed.
I have also never been in a car that takes longer than a minute or so to push cold air out of the vents, even in summer time weather.
Once the 8 minute mark has passed, the air stays cold at all times. I don't have any warmer air at idle or anything like that. It's gets cold and stays there.
I also can get in the car after it has sat for a number of hours and get cold air immediately. There is a certain point where it has sat long enough that we are back to the 8 minute wait time.
Is anyone else in a hotter environment who can advise on what their wait time typically is for cold air? I expect that I am not experiencing a normal functioning A/C.
Try replacing the aux battery - when was the last time you changed it? That was my culprit when I noticed the A/C taking time to build cold air, or simply not blowing cold anymore. Not saying that's your issue , but depending on how old your aux battery, could impact electrical components in the car.
Thread Starter
Newbie
Joined: Sep 2023
Posts: 13
Likes: 0
2005 E55 AMG
Try replacing the aux battery - when was the last time you changed it? That was my culprit when I noticed the A/C taking time to build cold air, or simply not blowing cold anymore. Not saying that's your issue , but depending on how old your aux battery, could impact electrical components in the car.
Refrigerant level is not something you can just check on a car. The system is filled by weight and sealed. You would have to recover the system with an A/C machine to know how much refrigerant was in it.
I do plan on buying some gauges to check the pressures at least before I take it to have the A/C further diagnosed.
MBWorld God!
Joined: Dec 2019
Posts: 32,222
Likes: 6,278
AUX battery shows 100% charge, and tests good. I believe it also is only connected to the SBC system. Not sure why replacing that would solve an A/C problem. The car will as apply a small charge to that battery when needed, then switch the charging back to the main battery.
Refrigerant level is not something you can just check on a car. The system is filled by weight and sealed. You would have to recover the system with an A/C machine to know how much refrigerant was in it.
I do plan on buying some gauges to check the pressures at least before I take it to have the A/C further diagnosed.
I will try this the next time I get in the car. What is the hunch?
Refrigerant level is not something you can just check on a car. The system is filled by weight and sealed. You would have to recover the system with an A/C machine to know how much refrigerant was in it.
I do plan on buying some gauges to check the pressures at least before I take it to have the A/C further diagnosed.
I will try this the next time I get in the car. What is the hunch?
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Thread Starter
Newbie
Joined: Sep 2023
Posts: 13
Likes: 0
2005 E55 AMG
Thread Starter
Newbie
Joined: Sep 2023
Posts: 13
Likes: 0
2005 E55 AMG
So I may have cracked the code.
I need to let the car rest / heat soak again, but I believe it is a sensor issue with the automatic climate control. I am pretty sure if I take it off of auto and just set the A/C to cold...it works right away.
Like I said, I need to test it out after letting it sit a while. Not sure what the sensors and automatic controls are doing for 8 minutes every time before getting cold.
I will be able to update if manual controls work tomorrow.
I need to let the car rest / heat soak again, but I believe it is a sensor issue with the automatic climate control. I am pretty sure if I take it off of auto and just set the A/C to cold...it works right away.
Like I said, I need to test it out after letting it sit a while. Not sure what the sensors and automatic controls are doing for 8 minutes every time before getting cold.
I will be able to update if manual controls work tomorrow.
MBWorld God!
Joined: Dec 2019
Posts: 32,222
Likes: 6,278
So I may have cracked the code.
I need to let the car rest / heat soak again, but I believe it is a sensor issue with the automatic climate control. I am pretty sure if I take it off of auto and just set the A/C to cold...it works right away.
Like I said, I need to test it out after letting it sit a while. Not sure what the sensors and automatic controls are doing for 8 minutes every time before getting cold.
I will be able to update if manual controls work tomorrow.
I need to let the car rest / heat soak again, but I believe it is a sensor issue with the automatic climate control. I am pretty sure if I take it off of auto and just set the A/C to cold...it works right away.
Like I said, I need to test it out after letting it sit a while. Not sure what the sensors and automatic controls are doing for 8 minutes every time before getting cold.
I will be able to update if manual controls work tomorrow.
Super Member
Joined: Nov 2017
Posts: 920
Likes: 163
From: Virginia
N/A
So I may have cracked the code.
I need to let the car rest / heat soak again, but I believe it is a sensor issue with the automatic climate control. I am pretty sure if I take it off of auto and just set the A/C to cold...it works right away.
Like I said, I need to test it out after letting it sit a while. Not sure what the sensors and automatic controls are doing for 8 minutes every time before getting cold.
I will be able to update if manual controls work tomorrow.
I need to let the car rest / heat soak again, but I believe it is a sensor issue with the automatic climate control. I am pretty sure if I take it off of auto and just set the A/C to cold...it works right away.
Like I said, I need to test it out after letting it sit a while. Not sure what the sensors and automatic controls are doing for 8 minutes every time before getting cold.
I will be able to update if manual controls work tomorrow.
I'll try max A/C auto and see what it does today.
Thread Starter
Newbie
Joined: Sep 2023
Posts: 13
Likes: 0
2005 E55 AMG
So the first time I put it in manual mode was at around 6-7 minutes of driving.
That's why I wanted to try again after a good heat soak. The car sat at the airport while I was out of town. Got in and had it on manual mode and set to 67* everywhere. Took 6-7 minutes to get cool.
The search continues. I haven't tried turning A/C off and on multiple times like the last user suggested. I'm out of town again. Will play with it when I get back.
That's why I wanted to try again after a good heat soak. The car sat at the airport while I was out of town. Got in and had it on manual mode and set to 67* everywhere. Took 6-7 minutes to get cool.
The search continues. I haven't tried turning A/C off and on multiple times like the last user suggested. I'm out of town again. Will play with it when I get back.
