2005 E320 CDI AC issues

[Bigdaddybenz]

Hey guys!!..... I'm gonna be all over the place on this one because it's simply not coming together in my mind and formulating an opinion based upon facts, so bear with me, please.

I have a 2005 E320 CDI and until yesterday the air conditioning worked flawlessly.

I noticed that when I parked with the AC on it got warmer. Now being an old school mechanic from the past I instantly thought that I must have a freon leak and it's low on freon. Once I began to drive the AC became cold again.

I decided to keep an eye on my on-dash engine temperature gauge throughout my driving all day yesterday. It remained between 90 and 100 degrees which looked like normal.

I came out of the store, started the car and a burst of smoke came from under the hood immediately. I shut the car down and by the time that I got the hood up it was already dissipating. I looked at everything and my wife stated that she saw it coming from the drivers side middle of the hood edge where it meets the fender. So, I assumed that maybe the overflow tank burped and let out a burst.... Just out of curiosity, I felt the high pressure (smaller pipe) line that goes to the evaporator right where a service valve is located on the driver's side fender well and it was really hot, almost as if it would burn my fingers.

I've felt the suction lines for coldness and high pressure lines many times on other vehicles when I recharged the freon in the past and have never felt a high pressure line feel so hot before.

I drove without the AC on the rest of the day.

I got home and was looking at the owners manual and it stated that if the coolant is low the compressor will disengage as a safety feature to minimize and damage.

I checked my coolant level and the overflow tank and the tank was empty, so I topped it off with the proper mix and anti-freeze, moved a few hoses to try to burp out any air pockets. All together it only took about 20 ounces of anti-freeze. Drove the car with the AC on and it worked flawlessly..

My concern is that the AC high pressure line and the condenser still feel extremely hot to me. I also was concerned because the electric fan never engaged so I'm wondering how can the condenser be cooling when the vehicle is not moving?. I checked the fan fuse in the trunk and it is good (continuity test out of circuit) and my engine temperature never seems to go up enough to engage the fan.

I will say that according to my on dash temperature gauge the car is running more around 75 - 80 degrees which is about 10 -15 degrees lower than it ran prior to me adding the anti freeze.

I'm very uncomfortable with what appears to be an excessively high temperature of the high pressure AC pipe and condenser. Maybe for a CDI it's normal, I had never checked it before.

In the past on other vehicles the only time that I've seen the high pressure line really heat up was if the expansion valve was blocked.

Anyone have experience with this or might be able to point me in the right direction?

Thank you all

[ROLLGUY]

I believe the cooling fan should come on when the A/C is engaged. Be sure it is operating properly. You might want to pressure check your cooling system, since you had to add coolant. A leaking water pump is common for these. Also, it should have warned you that the coolant level was low. An exhaustive check of all systems with a good scan tool (Icarsoft MB II or better) might also reveal the source of your problem.......Rich

[Bigdaddybenz]

Thanks Roll Guy, I suspect I will need to invest in a Icarsoft MB II or better

[Bigdaddybenz]

It's the electronic cooling fan!!!...... VERY expensive part!

[ROLLGUY]

Originally Posted by Bigdaddybenz

It's the electronic cooling fan!!!...... VERY expensive part!

I have a motor for one of these, but not the plastic fan blade or shroud. If your fan motor is the only thing bad, this will fix it. PM for details

[Bigdaddybenz]

Hi Roll Guy, I had already ordered a replacement fan assembly from ebay but it was incorrect, though the seller stated that it would fit an E320 CDI....

The CDI plugs in on the driver's side and a gas E320 fan plugs in on the passenger's side.

Also, I discovered that the E320 CDI man has a built in module with silver cooling fins, that module supposedly determines the fan speed when a signal is sent.

I had my Indy diagnose the fan as being faulty but he states that the module could be faulted as well and so it would be wiser to get the assembly.

If I knew it was just the fan motor, I'd simply replace the motor but my Indy states that there is no way to determine if it's just the motor or if it's the module failing as when he sent signals the fan never responded

If you have any ideas, I'm more than open to them

Thanks

[ROLLGUY]

The fan motor I have is actually from an '07 Bluetec, and I assume it is interchangeable with the '05-'06 CDI.