e46 Water Control Valve / Fan blowing Hot ??

[Charlie Brown]

Hi Fellow Fanatics

I have recently developed the following symptoms;

1.) Fan (both with and without aircon switched on / off) blows extremely hot air through the foot wells and the windscreen demister vents.

2.) The center vents are warm,

3.) I have an odd smell coming from the engine bay - it seems to be coming from water valve - and extremely hot to the touch.

Would I be correct in assuming that I need a new Water Valve ?

It seems so hot that it might burst, is it safe to drive and should I disconnect the electrical connector ?

 

[zippy320]

That can be a pretty expensive part to buy , so before you replace it , try taking it off , and cleaning it up and see if it helps its not difficult.

I did this to my car a while ago , Took it off , unscrewed the 8 screws , cleaned it up , sprayed it with carb cleaner ( not sure if it was safe to do but it cleaned up a lot of dirt that seemed to accumulate in there , flushed it with lots of water and fitted it back on . Make sure that spring moves freely and has tension etc

This vid might help , its easier on the 4 cylinder as its easy to see and work on .

Im not sure how you could test it but someone also told me that if you have an auto transmission , the transmission oil cooler thermostat ( It fits inside the radiator bottle sort of thing at the bottom) that can also get clogged , or break up due to the heat as its made of plastic and clog up with sediment or dirt . Its hard to get off without breaking it so be very careful or buy a spare replacement before trying to take it off, you might as well replace that also ( I replaced mine at the same time as when I cleaned the valve . The valve does get hot , Hot water flows through it .

Do a fluid change after you replace these parts.

 

[Charlie Brown]

Thanks Zippy.

Crap it is expensive no joke !

Still can't tell if it's a fuse, FSR, the valve itself or the vents. Still deciding.

 

[Zound]

I attempted to clean my heater control valve when I had a similar issue. Have you read through my AC troubleshooting thread? http://www.bmwfanatics.co.za/showthread.php?tid=58346

Maybe your AC is in need of an evac and recharge?

 

[Waseem 333i]

Normally it does get very very hot. remove the four screws holding it down. pull it out. see if plunger moves freely and take note if the small blue capacitor is there. Also look for any light grey smoke marks. That would suggest if its burnt. In sleep state the plunger is in the open position. When heater is off the plunger closes. To test turn ignition on at set fan to blow cold. No need to put AC on. Have someone operate controls while you check plunger. If plunger does not move freely take it apart, clean and grease. If it doesnt work at all then pull plunger down and jam a screw or something next to the shaft to keep it down. need to be very tight. The top up coolant from where the plunger goes it. The screw method will shut heater off which is what you want in summer while you find a replacement part. Second hand is fine to use.

 

[Charlie Brown]

Hi all

Thanks for the all the suggestions, I ended up booking it in to the dealers today, I had the outstanding Airbag campaign to do, so I just had them pull the codes.

Water Heater Valve - it arrives tomorrow and I'll pop it in over the weekend.

I will also have the aircon tested - I have normally used Canon Cool in Durban - any other suggestions from the Dbn guys ?

 

[Charlie Brown]

Thanks Waseem - very informative and helpful tips these much appreciated.

The electrical parts were all burnt out and the valve had a terrible odour. Valve was moving freely, but no way to move it with the contacts being burnt out.

 

[Waseem 333i]

My pleasure. This happened to me before.I put the screw to jam the plunger closed while i sourced a replacement. Its not fun driving in 30 degree temps with all windows open and heat coming out the dashboard even with fan off.