Blower Fan Problem

[x5inCT]

The white flakes are all related to the evaporator icing up - mine did the same thing too.

Outside of a basic A/C system problem (like a restriction in the refrigerant line, over or undercharged with refrigerant, lack of airflow across the evaporator, etc) I don't know what could be causing your problem. Could lack of airflow be the problem, like clogged cabin air filters? I googled "evaporator freezing" and undercharged refrigerant and lack of airflow are the two causes of freezing up of the evaporator - sorry, that's all I can offer!

By the way, who is checking your refrigerant line pressures to specs?

[Weasel]

Also the evaporator case has a temp sensor, the IHKA used this sensor to know when to slow down/shut off the compressor... Sometimes the sensor has either a minor air leak by it or is feeling warmth from the outer edge of the case etc. causing inaccurate readings and letting it run the evaporator too cold.

On some newer BMWs you can simply reprogram the AC to run a couple degrees warmer, but on the X5 it takes some carefully placed foam tape to correct if that is a contributing factor.

[c4racer]

hmm - mine had similar issues on longer business trip with 4 passengers yesterday. All was working fine and then we noticed no air was coming out - this was about 1 hour in to the drive. Worked fine on the way home for awhile, but again 1 hour or so into the drive the fan was blowing, but not much airflow was coming out of the vents.

Could this be the evap freezing problem? Would the first thing to do is have the AC system recharged?

Seems like a pretty tough thing for a dealer to reproduce since it takes about an hour of driving with the AC for the problem to show up.

[Weasel]

Since it is so hard to reproduce, and since the system has such a low capacity to begin with on the X5 (0.98 lbs) the best first course of action is to just have it recovered/measured to see how much is in it, vacuumed then refilled to the proper charge level via calibrated machine. Nowadays all the dealers have the computer controlled machines that do everything for you so almost any tech can do that without botching the job.

If for some reason that doesn't fix it, I'd look at the evap case around the temp sensor to ensure the sensor isn't getting any air leaks from outside the case making it think it is warmer than it is, as that could allow the system to run it too cold.

[c4racer]

Originally Posted by Weasel

Since it is so hard to reproduce, and since the system has such a low capacity to begin with on the X5 (0.98 lbs) the best first course of action is to just have it recovered/measured to see how much is in it, vacuumed then refilled to the proper charge level via calibrated machine. Nowadays all the dealers have the computer controlled machines that do everything for you so almost any tech can do that without botching the job.

If for some reason that doesn't fix it, I'd look at the evap case around the temp sensor to ensure the sensor isn't getting any air leaks from outside the case making it think it is warmer than it is, as that could allow the system to run it too cold.

thanks. I will have the dealer re-charge and test the system as a starting point. Seems to work just fine around here when I am driving less than an hour at a clip. No issues what-so-ever. Of course it acts up when I have a bunch of work collegues in the car with me

[petertn]

Mine does this too. sometime the fan blows inconsistently. hard sometimes and soft some times even when the fan itself is on the lowest blower setting. sometimes it turns of all toghether - but when i turn the car off and back on, the fan comes back. could this be the FSR too?

[Weasel]

Sounds like it, classic symptoms. Pretty safe bet going with the FSR.

[FSETH]

Weasel, the above posts are exactly what I PM'd you about the other day. When I get a chance, I am going to check the FSR connection as you told me, but I may want to make sure the system is fully charged as well. Damn thing was just charged a year or two ago.

My symptoms are spot on with the OP, mtimperman, Klavermi and c4racer.

[Rockmelon]

anyone tried switching to heater mode when such freezing symptoms appear?

[FSETH]

Originally Posted by Rockmelon

anyone tried switching to heater mode when such freezing symptoms appear?

No, all I do is turn the a/c off. After a few minutes the vents start blowing again and then I can turn the a/c back on and it will work fine for a while.