1st Gen R53 Cooper S Most liked posts in thread: New temp gauge registers hot.

The R56 can be difficult to "burp" all of the air out of the cooling system. On the waterpump / thermostat housing there is a bleeder screw #7 on the picture. The shop manual talks about turning the heater on and the fan blower. And to add small amounts of coolant to the overflow tank keeping it above the low fill mark. The dealers have a vacuum system that removes the air if you decide to go that route.

 

The R56 does run "hot" as an FYI. Mine in a highway cruise stays between 218-220 deg F with drops to 215 and spikes to 224. Now, 230 is definitely too hot. I'd say get a burp done by a shop and then have a look at it.

They mystery is partially solved by how the ECU decides to spin the water-pump as it is electric. If you had tunred your A/C to full blast you probably would have seen lower coolant temps as that tells the water pump to spin faster. Counter-intuitive from a mechanical water pump. If I have the A/C on full blast on the highway I will see cruising temps of 180 deg F with 5 degrees of plus/minus movement.

 

My highway cruise temps are identical to what Redbeard is seeing.

 

Happy to help. I just hope you get your issues solved.

I will point out that at standard op temps if you do lose a hose, get a crack in the system, lose a seal in the water-pump, etc... you've got a VERY short window to get the car shut down to prevent overheating issues as coolant will be spraying like crazy. :eek6:

 

That bleeder screw is hard to find. The first time I unscrewed the brake vacuum line instead.
If it's any consolation, I am also running close to 230 after installing a temp gauge, but I will try to burp the system some more. Let us know if you have any success getting the temps down.

 

I'm wondering if that is a variance related to location of the tap point for the gauge versus the ECUs temp gauge location.

 

The ECU temperature sender location is right at the thermostat If anything, it would register faster and higher than the sender at the hot link. At least until everything warmed up.

Dave

 

My Haynes guide was very specific about turning the heater on high and opening the windows while bleeding the cooling system (for an R53). I assume that it has to do with opening the valve to run hot coolant into the heater core so that you bleed those lines as well.

 

It could be that the gauge is out of calibration. If you have access to an OBDII reader, you could compare your gauge to what the ecu reads. I don't know if it's possible to calibrate it yourself - is there a calibration screw on the back? If your gauge is still under warranty then you should return it if it's reading high.

 

I think the assumption that the gauge is wrong might be suspect. If you think so, send it back to them and get a new one. More likely the temp is accurate and that is how hot the water is in that location. The factory uses a different location and the temp is different there.