No Heat

[WarrenBrown]

The 525iT is running low on heat with the drop in temperature here in the northeast. The cabin filter is new so I have airflow. The aux. water pump sounds like it is spinning. I'm suspicious of the heater valves. I heard that they should click but I'm hearing nothing. I've tapped them to try to free them but still not luck.

Are there rebuild kits available or do you just replace them.

Warren Brown
91 318is
95 525iT

[shogun]

rough price for a set is about $ 120,--. Replaced the ones on my car and the aux water pump some months ago. Worked 16 years w/o problem but they were due for retirement. I disassembled them after replacement just to check the inerts.

Remove the wire plug from the top of the valves, If they have no power, they should be open fully. If so, the valves are o.k, and you have to look for the control panel or the control module.

here some info on that

[granit_silber]

The 525iT is running low on heat with the drop in temperature here in the northeast. The cabin filter is new so I have airflow. The aux. water pump sounds like it is spinning. I'm suspicious of the heater valves. I heard that they should click but I'm hearing nothing. I've tapped them to try to free them but still not luck.

Are there rebuild kits available or do you just replace them.

Warren Brown
91 318is
95 525iT

My 525ia has almost no heat.
My problem is a failed t-stat. Apparently, BMW engineered their t-stat to fail wide open (kudos to them) instead of failing shut (like GM, Ford, etc...) the result is your engine won't fry out, but it also runs cold. The heat is drawn from the warmth of the coolant, so colder coolant=less heat in the cabin.
My engine gets out of the "blue area" when the temp is above 55 or so. When it's 70 here I get all the heat I want!

I don't know if this is your problem, but figured I'd share what I know.
-ashley

[Bill R.]

thermostats but frequently they break like this which is the same as failing open

My 525ia has almost no heat.
My problem is a failed t-stat. Apparently, BMW engineered their t-stat to fail wide open (kudos to them) instead of failing shut (like GM, Ford, etc...) the result is your engine won't fry out, but it also runs cold. The heat is drawn from the warmth of the coolant, so colder coolant=less heat in the cabin.
My engine gets out of the "blue area" when the temp is above 55 or so. When it's 70 here I get all the heat I want!

I don't know if this is your problem, but figured I'd share what I know.
-ashley

[granit_silber]

[QUOTE=Bill R.]thermostats but frequently they break like this which is the same as failing open
QUOTE]
Bill, Thanks for setting me straight. I was regurgitating what was told to me. So, I guess my t-stat really IS broken

-ashley

[granit_silber]

thermostats but frequently they break like this which is the same as failing open

Being a guy that really loves to know how things work, could you or someone explain how the t-stat works mechanically.
I understand the application and theories behind it, but fail to see how a spring loaded valve decides when to open and shut. What expands/contracts to open and close the valve? Why do they fail? How do the builders determine the degree or opening temp of the t-stats?

-ashley

[Mr Project]

Dip one in a pot of boiling water for a minute sometime. Kinda cool.

It's a matter of expansion rates of certain metals at certain temperatures, IIRC.

[Bill R.]

middle in a sealed chamber with a ram like a hydraulic cylinder.. when paraffin is heated or cooled it expands considerably causing the ram to move and open or close the thermostat... On a side note the newer bmw's now have electric thermostats...

Dip one in a pot of boiling water for a minute sometime. Kinda cool.

It's a matter of expansion rates of certain metals at certain temperatures, IIRC.

[Mr Project]

Really? I cut a thermostat open a number of years ago and there was no wax. Of course, who knows what car that was from....or if the wax had somehow leaked out or something at some point.

[Bill R.]

1

Really? I cut a thermostat open a number of years ago and there was no wax. Of course, who knows what car that was from....or if the wax had somehow leaked out or something at some point.