NEED AC HELP
Thread Starter
Newbie
Joined: Jun 2025
Posts: 1
Likes: 0
NEED AC HELP
Hi All,
Summer is here and a 3 hour drive with no heat in 80 degree weather has me desperate for cold, cold, AC. I am by no means an expert at AC repair so any help is appreciated, however, I have a good general knowledge on the topic.
The details:
I drive a 2008 ML350, W164 with 272 engine
The A/C went out sometime last summer (2024) and I have slowly been trying to identify the issue at hand.
There is absolutely 0 refrigerant in the system so there is a leak. After pulling a vacuum for around 10 min and pressurizing with a can of r134a, I can hear a slight hissing close to the dash on the driver side while in the engine bay. I am talking about the space between the car body and the rubber seal/firewall that partitions off the engine, near where the AC lines run in towards the evaporator.
I am unable to get the compressor to cycle to completely refill the system.
I am lost on why the compressor won't run and what the leak may be from without tearing the car apart to look at the evaporator.
Thoughts?
Summer is here and a 3 hour drive with no heat in 80 degree weather has me desperate for cold, cold, AC. I am by no means an expert at AC repair so any help is appreciated, however, I have a good general knowledge on the topic.
The details:
I drive a 2008 ML350, W164 with 272 engine
The A/C went out sometime last summer (2024) and I have slowly been trying to identify the issue at hand.
There is absolutely 0 refrigerant in the system so there is a leak. After pulling a vacuum for around 10 min and pressurizing with a can of r134a, I can hear a slight hissing close to the dash on the driver side while in the engine bay. I am talking about the space between the car body and the rubber seal/firewall that partitions off the engine, near where the AC lines run in towards the evaporator.
I am unable to get the compressor to cycle to completely refill the system.
I am lost on why the compressor won't run and what the leak may be from without tearing the car apart to look at the evaporator.
Thoughts?
Junior Member
Joined: Feb 2007
Posts: 19
Likes: 0
From: Fredericksburg Virginia
Mercedes 2010 ML350 4matic
Hi All,
Summer is here and a 3 hour drive with no heat in 80 degree weather has me desperate for cold, cold, AC. I am by no means an expert at AC repair so any help is appreciated, however, I have a good general knowledge on the topic.
The details:
I drive a 2008 ML350, W164 with 272 engine
The A/C went out sometime last summer (2024) and I have slowly been trying to identify the issue at hand.
There is absolutely 0 refrigerant in the system so there is a leak. After pulling a vacuum for around 10 min and pressurizing with a can of r134a, I can hear a slight hissing close to the dash on the driver side while in the engine bay. I am talking about the space between the car body and the rubber seal/firewall that partitions off the engine, near where the AC lines run in towards the evaporator.
I am unable to get the compressor to cycle to completely refill the system.
I am lost on why the compressor won't run and what the leak may be from without tearing the car apart to look at the evaporator.
Thoughts?
Summer is here and a 3 hour drive with no heat in 80 degree weather has me desperate for cold, cold, AC. I am by no means an expert at AC repair so any help is appreciated, however, I have a good general knowledge on the topic.
The details:
I drive a 2008 ML350, W164 with 272 engine
The A/C went out sometime last summer (2024) and I have slowly been trying to identify the issue at hand.
There is absolutely 0 refrigerant in the system so there is a leak. After pulling a vacuum for around 10 min and pressurizing with a can of r134a, I can hear a slight hissing close to the dash on the driver side while in the engine bay. I am talking about the space between the car body and the rubber seal/firewall that partitions off the engine, near where the AC lines run in towards the evaporator.
I am unable to get the compressor to cycle to completely refill the system.
I am lost on why the compressor won't run and what the leak may be from without tearing the car apart to look at the evaporator.
Thoughts?
Newbie
Joined: Sep 2025
Posts: 2
Likes: 0
ML300, GLE350
Hi friend,
I also had AC problem last month. But it was caused by the failure of a certain resistor in the sensor, which led to the AC tripping. It will be okay if you step on the accelerator deeply several times and drive for a certain distance. Now I have taken it to the repair shop and had it fixed. It's a bit different from your problem, but I hope it inspires you.
Best wishes.
I also had AC problem last month. But it was caused by the failure of a certain resistor in the sensor, which led to the AC tripping. It will be okay if you step on the accelerator deeply several times and drive for a certain distance. Now I have taken it to the repair shop and had it fixed. It's a bit different from your problem, but I hope it inspires you.
Best wishes.
