w211350w202280

Hi All,

Longtime listener, first time caller.

I do beg your pardon in advance if this has been covered before. I just couldn't find an original thread so I thought I would start my own.

I have a 2006 W211 E350 with an M272 E35 engine.

I have noticed that after about 20 minutes the fan is kicking in on high (but not the highest setting, I have heard that before and its really loud).

The coolant temperature seems to be going to just under 100degC on the gauge then dropping to just over 80. I can only check the temp from the OBD2 reader when home and it says 94degC.

No fault codes (using Torque Pro, not S.T.A.R or otherwise). No lights on the dash either.

I have had the following changed/work done (which isnt an issue as I try to have one or two things changed at every visit):
1. Thermostat.
2. Coolant Temperature Sensor (that copper sensor behind the engine, on the bock (I think) that no one has ever seen before or knew how to fit).
3. AC re-gased (after 8 years!) - I assumed it may have been the fan working harder because of the gas being low.
4. Checked that the existing water pump was good (during 5 below). It was.
5. Coolant change (incl. top up) - No bubbles that we could find.

Of course, I would estimate the car is putting out between 400 and 600kW in heat so I would expect it to be on with the heat. Perhaps my ears are just a bit sensitive these days. But I was wondering if there is anything I have missed?

Thank you in advance and for all the years of help you guys have given me.

w211350w202280

I should add:

1. The cooling fan also becomes a bit loud when I park up.
2. I realise I wrote Lout not Loud in the title. Its been one of those days lol.

juanmor40

Was the AC system emptied? Vacuum and filled with the exact weight of refrigerant as specified in the sticker/label under the hood?

An overcharged AC system will trigger the fan at its highest speed if the pressure in the system is too high, i.e. @20bar.

If you have an AC with "climatronic" you should be able to monitor several temperatures, and refrigerant pressure w/o using any scanner.. Check if yours support what is shown in this video

It is strange that is happening after the car has been sitting for 20 min. let me think.

w211350w202280

Hi juanmor40,

Thank you for the reply and the video.

Please see answers below:
1. Was the AC system emptied? Vacuum and filled with the exact weight of refrigerant as specified in the sticker/label under the hood?
An overcharged AC system will trigger the fan at its highest speed if the pressure in the system is too high, i.e. @20bar.
A: I am honestly not sure. I took it to a garage who popped it onto a machine and I went home. Their website states:
The recharge process is quite simple and involves removing any old refrigerant gas and oil from your air con system before replacing this with the correct amount of new refrigerant and lubricant as per your vehicle manufacturer’s recommendation.
However, I wasnt there. Is there a way I could check?

2. If you have an AC with "climatronic" you should be able to monitor several temperatures, and refrigerant pressure w/o using any scanner.. Check if yours support what is shown in this video
A: Thank you for taking the time to find and share the video. My AC unit does look similar but I think the display is different. I have sent this to my phone and printed off the list of commands. I will try and look at this over the weekend and get back to you.

3. It is strange that is happening after the car has been sitting for 20 min. let me think.
A: The car isnt sitting. It is after 5 mins of regular town driving, 2 mins of 50mph and another 15 mins of so of 70mph driving. It just so happens that at around the 20 min mark, I pull up to work and slow down to park (where I hear the fan ramping up) but I have also heard this in the car with the stereo off.
The fan kicks high which I never really noticed after 9 years of owning the car.
Sorry I should have written this better yesterday.

w211350w202280

Hi juanmor40,

Quick update to question 1: I spoke with the garage who did the regas. They have an AC expert coming in to review another car on Tuesday (30th Aug). They asked me to bring mine and they will ask that he reviews it as well.

I will come back to you with an update with that. Thank you for telling me to have a look at that.

w211350w202280

Hi juanmor40,

I do beg your pardon for the 3rd message with no real update.

I have tried the hidden menu in the video but unfortunately my cluster is different.

My cluster is below.

I will come back to you with the results of the AC technicians finding when I get them back.

Again, thank you for your help.

juanmor40

No worries.

Whenever you can, even if you get your issue resolved, try pressing the left "Auto" round button for a few seconds instead. That is how I can get into my sister's W211 AC menu. It is possible you do not have the "climatronic AC". You may need to look at the vehicle's datacard using your WIN

https://www.lastvin.com/

w211350w202280

Hi juanmor40,

Thank you for all your information. I checked ran the VIN and my car doesnt have 'climatronic AC' unfortunately. I tried pressing AUTO for around 10 seconds all the same and no luck.

I took the car into the garage who did the work and they checked the system and confirmed it was regassed correctly and to the specified pressure.

Something funny has happened, however:

I took the car for a 3 hour journey and when I got to my destination my fan was running correctly. The temperature was holding between 80degC and 100degC (176degF and 212degF).

Where the interesting part is I was driving locally, perhaps 2-3 20 min journeys, and the fan was running quite high which is understandable because the car is trying to get air over the radiator to cool it. The temperature, again, was holding between 80degC and 100degC (176degF and 212degF). But I just havent heard it so high before.

juanmor40 one more thing, cheers for being there to help me. I know I haven't come back to you as quickly as I could have and wanted to apologise for that.