Have I got an auxiliary water pump?

[Muleears]

I was driving my new-to-me '05 X5 with the 3.0 in the snowstorm in Virginia today (it did wonderfully), I noticed when I stopped for more than a minute or two the heater would stop working. Fan would blow but the air was cool. In my old Benz there was an auxiliary water pump that kept coolant moving when the motor was running slow and the regular water pump wasn't moving much. I notice when looking for parts, there is an electric water pump also available. Is this for an auxiliary system of some sort or is it like the one on my benz? Either way, why is my heat going away when I sit and idle for a few minutes? Cooling system is full. Maybe need a burp? Help me out. Thanks in advance.

[Overboost]

You should have one. Sits on the drivers side fender well right behind the air box. #15 in this diagram. Some have said these can fail but they usually make noise first.

RealOEM.com - Online BMW Parts Catalog

[Muleears]

Thanks Overboost. I may not have heard the pump fail as I have only owned this for about 10 days. It may have died before I took ownership. Would this be the cause of my no heat when idling situation?

[cn90]

The thermostat may soft-fail (open too early).
Or your WP may be bad (impeller fell off) etc.

At this age/mileage, search forum for cooling overhaul.

[Muleears]

Originally Posted by cn90

The thermostat may soft-fail (open too early).
Or your WP may be bad (impeller fell off) etc.

At this age/mileage, search forum for cooling overhaul.

Thanks for the information. Wouldn't it overheat if the impeller fell off? I drove about 100 miles today and other than the no heat at idle situation the cooling system seemed to do well.

The soft fail thermo could be the problem too, is there any way to check without replacement? I know they are pretty inexpensive to replace but are there any other symptoms, like extremely long warmup time? Or running too cool?

[wpoll]

Have you unlocked the BC hidden menu and monitored the KTemp (#7)?

[Muleears]

wpoll, nope and have no idea what that is... I guess I'll do some more searching! What am I looking for once I start monitoring this temp? Thanks again, BTW.

[wpoll]

Originally Posted by Muleears

wpoll, nope and have no idea what that is... I guess I'll do some more searching! What am I looking for once I start monitoring this temp? Thanks again, BTW.

If you have the "high" cluster (with a line of text along the bottom display)then have a read of this...

BMW X5 - Access the Hidden Onboard Computer (OBC) Functions.



*edit* note that this info (linked above) contains an error - you need to add all FIVE digits from your VIN (not four as stated).

[Muleears]

Originally Posted by wpoll

If you have the "high" cluster (with a line of text along the bottom display)then have a read of this...

BMW X5 - Access the Hidden Onboard Computer (OBC) Functions.

Thanks, but I'll have to read it tomorrow, work is only 6 hrs. away and I haven't gotten any sleep! Thanks for the help. Signing off for the evening!

[wpoll]

Just re-read the info. in the link I just sent and I note it has an error - you need to add al FIVE digits of your VIN - not the last four as stated.

From Qsilver7...