XSeries-forum

had a bit of a worry yesterday, coming home from the shops, noticed temp gauge almost in the red, dunno how long it had been creeping up there, got home. not I know it was a hot day but , really?.
lifted bonnet , cars running sweet as usual , fan spinning as normal ,

turned car off and left it ,
water level  ok. and oil level ok ( checked when cooled)
checked codes with scanner 1.41. came up with nothing , apart from I think check coolant level, but im certain that was an old code from when my WP went.
is there anything these engines are prone to doing when warm ,
or am I just worrying too much?

theres something up with it, is the auxillery fan (the electric one on front of rad) working? i had similar other year with my m3, stationary slow traffic guage right in red when driving it was fine, it turned out to be the aux fan

+1 on the electric fan as being the likely cause. Does the temp drop when moving?

im going out in it today ,shall have a look and report back when its hot

just to update you guys,
fired beasty up ,  sat  there idled for 30 mins (while I was cleaning garden)
1/2 temp solid
went on motorway shortly after , got about a mile or 2 and the guage started creeping up , right up nearly to the red,  but not quite,  pulled car over opened bonnet, NO fan on front of radiator
put heating on , full and hot , temp came down , limped car home ,  turned heating off, outside house, guage increased,  still no fan

either fan or sensor ,
I read codes again this morning , says nothing about a temp sensor failing

can you test these fans ?

my fan had noting easily testable so just chanced it, yours is actually doing the opposite to mine though, what about water pump?

If it's just an on/off 12v feed so if you put 12v on the +ve side (brown is negative on cars) it should fire up.  If it uses a 3-wire feed then it may use a PWM (non-DC waveform) control signal to run it.  PWM fans are much trickier to test as they need a waveform generator.

[quote="X5Sport"]
If it's just an on/off 12v feed so if you put 12v on the +ve side (brown is negative on cars) it should fire up.  If it uses a 3-wire feed then it may use a PWM (non-DC waveform) control signal to run it.  PWM fans are much trickier to test as they need a waveform generator.
[/quote]

mine went through some sort of control module first and was no way of testing it, what i did was got it up towards red and jumped out popped bonnet and plugged new fan in just laid on top of front pannel, new fan fired straight up when old one had never worked, so then i fitted it and never saw the guage move off half

2 thick wires and a thin one ,

get it up to 3/4 not good to keep taking it to red and get out and look if the aux fan has kicked in

na , that's it , no more , running till I find out what the issue is ,

again , read codes, nothing in there ,
can you use another software to fire up the fan from the scanner??

No.  It either runs or it doesn't.  A square wave generator will be the only thing, or try one off another car.  Sounds like you need a new one unfortunately. 

that wasn't the answer I was hoping for
hell there expensive !

i got a used one from ebay,

The fan should self test on start up. It should spool upto half speed for a few seconds and then stop. They do throw a code if this doesn't happen. Get someone to start her up while you watch the fan, if it does a dance back and forward chances are the motor is dying. also it should switch in at 100 deg to help the viscous fan out. The stats fitted to these don't open till 105deg, there are a couple of options for fitting cooler stats which is a good idea on these beasts as the cooling system is on the edge of danger most of the time, a small issue like you have an wammo, overheat time.