Hey guys and gals. I’m completely stumped here. Looking for help, please and thank you.

my 2010 r56s had a leak from the thermostat housing so i replaced it and put the ecs aluminum crossover pipe on as well while i was at it.

I put coolant back in, turned the heat on full blast and bled until coolant was a steady pour from the bleeder screw.

Heat is coming from the A/C, and the temp goes from 209-211 or so while at idle. But as soon as i start driving the temps jump to 225-231. I’ve bled it several times, but i’m still having the same problem. Anyone have any idea what may be causing this? I have to turn the heat on full blast while test driving to get the temps to drop, but they hardly drop below 220.

Normally my car stays at 209-211 degrees while driving. It only rises if i sit at idle for a long period of time.

It’s almost like it’s working backwards.

So frustrating, I’ve been at this all day. Thank you for any help/ideas

 

To be honest you’re probably good. On my former R55s when I swapped my thermostat, yes I used oem, my temps were in that range as well when sitting still. Would run about 220, when in motion. I really think they made a change with the thermostats causing them to run hotter. The one I replaced never saw temps above 220 no matter what, and would run around same temps you stated. I bled that system 3 times and just lived with it running hotter.

 

Hopefully that’s the case. I replaced the new temp sensor with the one from my original thermo in hopes it would read 209 degrees (like it had been), but it still read in the 220-225 range. Took it out for a little hell run just to see what would happen. It stayed in the 220-225 range pretty much the whole time. Once it went to 231, but dropped quickly back down to 220. Heat and A/C work like they should, and everything seems to be running smoothly. No loss of coolant or anything.

Guess I’m just going to have to get used to seeing the scan gauge read in the 220 range instead of 209 range. I constantly watch engine temps out of habit. Can’t have my baby get too hot!

 

When I changed my thermostat housing, I had to bleed the system at least three times. Also checked the bottle reservoir daily to make sure it was full or needed coolant, which it did a couple times.