I own an r57, but Im doing it here because it is a more active section and my question has nothing to do with the body type.

Recently, my 2015 r57 has stopped popping 99% of the time in sport mode. I think it could be weather related as its been cooler so Ive been having the heat blasting and I know the pops are related to heat so is it possible that with the outside temp and the heat on full blast, my car is not getting hot enough to pop? I do gain the performance gains and throttle response still so I know the button is working and frankly, I dont miss the pops, I just know that the pops are related to the timing so Im worried it could be related to the timing. Its a 2015 with 89k miles on it and no death rattle. Thanks!

Here's a random PFA

 

Fault codes?

 

None, my bad

 

My understanding is that, in sport mode, the DME commands the fuel injectors to deliver excess fuel to the cylinders during deceleration. You may want use a scan tool to check whether the expected rich condition during deceleration is now absent.

 

"Timing" when talking about pops and bangs out the exhaust is not the same "Timing" when talking about the timing chain.

I would chalk it up to the colder weather, unless you start having other is

 

Its the weather, with heat on full blare and car in sport, it wont go above or maintain 165⁰+ F which seems to be the point at which pops start unless Im mashing on it (Im not because it is in town) or going up a steep hill. Once the coolant passed 165 on the hill, it popped but then dropped temps back to 163 and stopped popping. Im going to chock it up to the aggressive hvac in convertible cars.

 

if the coolant temperature will not go above 165°F, then you have a thermostat failure. Normal operating temperature should be ~210°F, and sport mode should drop that temperature to ~190-195°F. Probably only a matter of time before the thermostat code gets saved.

 

duh cant believe I forgot about that. I put an aluminum one in in march, but Im realizing it is a bremmen one which apparently has a bad rep. Ive only done short trips, so Ill take it to a couple town over and see if I get up to temp or not. Rein is the original manufacturer for genuine mini tstats, right? I dont mind paying the extra 50 for the genuine mini, but if I cave money on identical parts and build quality, I will.

 

ECS offers lifetime replacement for those thermostats. Might have to take them up on that one.

I had purchased a Bremen plastic thermostat for my Clubman. Lasted me about 3 years before failing. This was before ECS started offering lifetime replacement warranty. I ended up replacing it with the OEM Mini thermostat, since the cost difference was minimal at the time. Still looks like the OEM Mini thermostat is reasonable cost at ~$150.

 

The need to have the heat on full blast also may be consistent with a stuck open thermostat.

 

That is due to the fact that it is an r57 and I have put the top down in as low as 30⁰ F so far lol 😅 The temp varies at each setting and it still pumps out warm air at the lower temps. The max temp is a personal choice.

 

 

Ive been playing around testing out different patterns. Heat off, the thermostat acts perfectly normal. Itll get to 222 and then drop to 212 F. In sport, itll go to about 185 and drop 180ish. However, if I dont let the car warm up first and turn the heat on straight away, it wont surpass 158 unless Im really getting on the car. If I let it heat up fully and then crank the heat, itll be 172-176 for normal and 170-174 for sport. Im half considering a weird electric issue and half chocking it up to the fact that convertibles version of most car models have a more aggressive cabin heating system. In the summer, with the AC on or off, the temps were normal. Unfortunately, theres no warm days on the horizon to verify that the thermostat still acts normally then.

 

I’d be tempted to think the thermostat is acting correctly, but not as designed. 158° is too cold for coolant temps, regardless the operation of the heater or not.

 

So I replaced my battery today as the car wouldnt start this morning without a jump. Registered it in bimmercode and bimmerlink. While checking errors, I found code 9c90, however, Im having no issues with the heating and ac (all fan speeds and temperatures work and are varied). Can this code be related to the hvac system pulling so much engine heat?

 

Code 9C90 was likely caused by the low battery that you replaced. Clear the code to verify that it does not return.

 

The code is being stubborn and wont clear but weirdly enough, all temperature issues I was having are gone with the new battery. Car drives so much better now too, hard to notice it when it goes bad so gradually.

 

Is the code listed as active or present?

This is great news. Maybe the weak battery was the underlying issue. Good luck.

 

Present.

And yeah, the car runs so well now. I stalled it for the first time yesterday backing up my steep as driveway and was so confused as I hadnt done that since like week 1 of owning it. I then did the same today and almost a second time, even. Post battery change: the car feels so much more peppy and light and went up the driveway effortlessly. I feel so dumb for not thinking battery 🙃

 

Maybe it will resolve itself? Otherwise, take notice of any type of climate control issues.

Great!