thermostat question- for anyone that's done one

[shadrack]

So I've put a thermostat in both x5s I've owned but both times it was in deepest winter so anways ran very cold - middle, anyway I've a suspect thermostat on the m3 when driving its running cold 1\4 on guage however when going up a long drag behing a bus at 10mph or in stop start town its creeping over 1\2 and towards the 3\4 then you get going and back down low, so has anyone else had this on an x5 or changed a thermostat in warm weather,
I'm ruling out waterpump as I think it would be straight red hot within minutes, the viscous fan although stopped with not loads of force has a lot of friction when engine off and will not spin,

[storminmike]

[quote="shadrack"]
So I've put a thermostat in both x5s I've owned but both times it was in deepest winter so anways ran very cold - middle, anyway I've a suspect thermostat on the m3 when driving its running cold 1\4 on guage however when going up a long drag behing a bus at 10mph or in stop start town its creeping over 1\2 and towards the 3\4 then you get going and back down low, so has anyone else had this on an x5 or changed a thermostat in warm weather,
I'm ruling out waterpump as I think it would be straight red hot within minutes, the viscous fan although stopped with not loads of force has a lot of friction when engine off and will not spin,
[/quote]

I've just had mine done on the X5. It flatly refused to go beyond the first tick unless it was sat in traffic and even then it never dead centred. My Webasto doesn't work either so that didn't help and the fan seemed a bit stiffer than seemed normal....however

The thermostat has just bee replaced by my indy and it goes dead centre now in a reasonably quick time. I can be certain but the give away was he undid the res cap and waters going in...and he fealt the bottom hose too.

Cost..£112 including £15 worth of new coolant and vat..fitted.....ouch...but at least it's warm and the engine n longer complains as much

[shadrack]

yeh ive done the stat on my previos x5 however the buit i dont understand is why its going to 3/4 in traffic, im putting a stat in and doing a rad flush and new coolent as a precaution but im thinking viscous coupling or auxilery fan. anyone know a good way to test either of them

[storminmike]

[quote="shadrack"]
yeh ive done the stat on my previos x5 however the buit i dont understand is why its going to 3/4 in traffic, im putting a stat in and doing a rad flush and new coolent as a precaution but im thinking viscous coupling or auxilery fan. anyone know a good way to test either of them
[/quote]


....ahhh.... I misunderstood...you mean it's overheating not under heating.

Not sure I can help here....sorry

[shadrack]

[quote="storminmike"]
[quote="shadrack"]
yeh ive done the stat on my previos x5 however the buit i dont understand is why its going to 3/4 in traffic, im putting a stat in and doing a rad flush and new coolent as a precaution but im thinking viscous coupling or auxilery fan. anyone know a good way to test either of them
[/quote]


....ahhh.... I misunderstood...you mean it's overheating not under heating.

Not sure I can help here....sorry
[/quote]

its doing both, when driving its cold, when still its getting warm