Excessive engine or radiator fan noise?

[triom]

Hi all,

I have had my 2008 128i for about 8 months, been pretty happy with it except minor problemsmans normal maintenance which has made me bring the car to the dealership once in a bit (under warranty mostly). 2 months ago, when it was average early 20 degrees celcius temperatures, I found one of my fans going at full blast after doing a run at a local mountain where it is mostly highways (the fan was so loud that it felt like a bus staying by the side of my car). It became more evident when I got back to stop-go city congestion. The fan continued to go loud and I guess full blast thereafter even when I drove to work (approximately 15 minutes and 12km in the city) in similar temperatures. I took it into the dealership and they found that my thermostat was malfunctioning and that they replaced it - note that no lights lighted up on dash. The sound seemed to have subsided though when I car idles it seems the low end humming / vibrations seem more than before.

Fast forward to current temperatures 26 to 31 degrees celcius with me having a/c on inside the car most of the time, it seems the fan action, which is not as loud as before and can only be heard occasionally from inside the car is coming back. I remember one of the foremen telling me that the fans may work harder during hotter temperatures. My question is, is this normal around these temperatures. Is there anyway to know what would be constituted as normal fan behavior?

Thanks in advance for your help. I know the best action is to take it back to the dealership, but it's more busy these days and it is a pain to have to bring it in if it is normal behavior.

T.

[triom]

I think I may have put this in the wrong category as I have not modified my vehicle. Moderator if I am in the wrong forum could you put me to the right forum? Thanks.

[andrey_gta]

I dont usually blast my AC.
After i park, the car still has its fans working but no air is entering the cabin, i guess this is for cooling and very quiet.
if i am in the car for 5 more minutes, i can hear certain ventilation stopping.
Even in the winter i heard this noise

[Lester]

I Never hear any fans on my 2008 and I also live in Vancouver.

[wolfe]

I find that the fan shuts off when I shut the car off, even in the middle of summer. Not sure if this is normal or not, I'd expect it to keep running for a bit.

[triom]

audrey_gta and wolfe: but do you guys hear the fan running with closed windows? Almost like a quite van or bus to the side of your car when the car is idle?

lester: thanks. Just have to reproduce it if I bring it back to the shop now if it is abnormal.

[andrey_gta]

nope the only fan i hear is the interior fan , if its working.

If i stand in front of the car, i may hear the radiator fans

[wolfe]

No, I can't hear the engine fan with the windows closed. I think if I had the interior fan off and was not moving I could just about hear it.

[Greenkirby21]

I could definitely hear it today when the car temp said it was 110! Texas heat ftl

[texasmojo]

Mines very loud too. But only when the AC is running. I think its normal on 128i.

[KellyK]

Originally Posted by texasmojo

Mines very loud too. But only when the AC is running. I think its normal on 128i.

same!

[Missy101]

I am worried about this also.
No warning so dealer says no issue and wont even check my car.

Coolant temps are 102c on motor way doing 70-80mph
Temps in town or stop start can be from 99 - 104c

Thing that worrys me is car reports coolant temps of 96c today when parking up after 200mile drive and fan is on loud in engine bay and oil temp was normal 90-100.
Dont understand why the fan was running at all

[Dackelone]

One of the first signs of a bad or failing electrical waterpump is that the radiator fan runs at high speed. Even before the waterpump fails totaly, it will thru a code. You might have a dealer read your car for any code. And don't have them read the key fob, but the car's fault memory. The key fob will not store every fault... but the car's memory usually does.

[flinchy]

sounds like the noise my AC makes every time i turn it on,, got a video?

the noise my AC fan makes even after the car is off for a few seconds, is VERY loud.

[135i OREO]

FYI guys, my 135i was doing this when I turned on the A/C. It was fine for a while, then one day, the fans were very loud. If I put the window down, it would sound like I had the MAXCOOL option turned on the JB4. This was in August when it was hot for once here in Germany. I didn't pay much attention to it and then in the begining of November, as I pulled into the grocery store, the fans came on full blast again, but I didnt have the A/C or heat on. Left the store, 2 miles later, my waterpump went out. Like Dack said, I believe the sound you are hearing is a early warning sign of the waterpump going out so keep an eye out. If it ever get to the day that you turn on your car and the fan turns on full blast within 10 seconds, your waterpump is no longer working (or a fuse blew). So keep and eye out.

[Missy101]

Confusing but good advice thanks.
Confusing because my pump was replaced a few days after i collected the car. I had a engine temp warning yellow then red so pump was replaced.

Need to get car scanned again with Dis but last time it was scanned a few days ago it only showed what looked to be old code for T stat that was never replaced by BMW, just the pump.