[bongko]

So I have a 2016 M235i F23 auto that I bought used ~37k miles. After reading lots and lots of threads and stickies here regarding preventative maintenance and watching alot of youtube DIY I decided to do all of the mods myself.
99% of videos that I watched were of people who had the F22 and since the engines are the same I figured the F23 would be a simple monkey see monkey do.
Things I ordered:
FMIC, intake, and charge pipe from CTS turbo (zero fitment issues; I was in disbelief how easy it was after watching/reading horror stories on fitment of some bolt ons)
ATF kit, oem plugs, cabin filter, Akebono brake pads and coolant reservoir line from FCP Euro
steel brake lines
dealer for coolant, rear diff oil and brake fluid.
It took a good month to get everything together and do research to make sure I had a good idea how to approach everything.
I started at the top with the plugs, intake, brakes, brake line and flush, and removing charge pipe. When I took out the spark plugs there was some rust left so I just used a shop vac. Brake flush used about 3 bottles of fluid. No problem, going smooth. Then I get the car on jacks and take off the bottom cover.
1st difference between F23 and F22. There are two metal bars that are on opposite sides in the middle of the car and meet at a point near the front middle of the car right under the intercooler. There are also similar bars that meet at the middle in the rear right underneath the rear differential.
I was able to get the nut in the front off with a Torx key (largest one I had that didnt snugly fit, maybe a T60 would fit but didnt have one then) so I could work on the charge pipe, FMIC, and coolant but couldn't tighten back confidently as I was afraid of stripping the nut. Changing the rear diff fluid was a pain as I did not want to take out the nut holding the bars again so just had to work different angles trying to get the rear diff nut off. The FCP Euro vid shows the guy taking the nut off in 10 secs; took me 10 min trying to wiggle around and not have the car fall on me before I could take it off.
The ATF kit from FCP Euro worked perfectly and besides the god awful rear diff and AT fluid smell and the inevitable spilling from filling them things went smoothly. Used 6.5 bottles of ZF trans fluid and two full bottles of rear diff fluid (expensive stuff so don't spill). Did I mention they stink? Stinks worse when you heat up the ATF and let it spill out all over the place.
The only other thing that was different on the F23 was that I did not find the aux radiator in the driver side front bumper. There is nothing there. I planned on using the aux radiator to drain the coolant for a drain and fill but was shocked to find nothing. I drained ~1.5 gallons of the coolant from the coolant hose. I didn't bother to open the passenger side to see if the oil cooler was there as the project took alot longer then I thought and I was stinking of diff and trans oil. God I can still smell it and I did all this about two month ago.
Anways a big thanks for all the great info and advice from forum members as I felt very prepared to tackle this project and have had no CEL or any issues the last two months. The car feels smoother overall and the more audible turbo spoiling noise definitely make all the work feel worthwhile. My next project is getting new wheels/tires but this rabbit hole seems very dark and twisted.
Going forward I know that I need to watch for the OFHG, valve cover gasket, tensioner belt, and the water pump and thermostat. If there is anything else I should be mindful of please let me know.

[123Britt]

This part is definitely a must change every 5 years.

This tube runs from Coolant reservoir tank across top of radiator to drivers side of radiator and is know to break at anytime.
.
Simple and cheap preventative maintenance.

[bongko]

Originally Posted by 123Britt

This part is definitely a must change every 5 years.

This tube runs from Coolant reservoir tank across top of radiator to drivers side of radiator and is know to break at anytime.
.
Simple and cheap preventative maintenance.

Thanks, I did buy it from FCP Euro and was going to change it when I drained the coolant but the current one still looks good at the joints. I ended up not changing it and put it in the trunk. I'll take a look around 50k miles when I change the water pump and thermostat

[M235SDCA]

If you have the hose just change it. My 2016 F23 / M235 had it go at about 45k miles. Fortunately it was under warranty and I was close to a dealer.

So well done on the mods / maintenance.

[bongko]

Originally Posted by M235SDCA

If you have the hose just change it. My 2016 F23 / M235 had it go at about 45k miles. Fortunately it was under warranty and I was close to a dealer.

So well done on the mods / maintenance.

Ok no waiting around then! Did you have any issues with the water pump or thermostat? I figure I might as well do everything while I have the car up again.

[M235SDCA]

Originally Posted by bongko

Ok no waiting around then! Did you have any issues with the water pump or thermostat? I figure I might as well do everything while I have the car up again.

No, never had an issue with either one. Actually very few issues with the F23 at all and at about 55k now - even with the tuned engine. Not sure I would proactively change either one as they are a bit of a PIA - at least it was on my F10. Next thing I probably have to do the same trans fluid change you did.

One issue I've had is the hub clicking issue that needs the $40 friction disks from BMW that go between the rotors and the hubs. Did that about 18 months ago and the problem is back. Ugh! Now I'm just going to live with it. Only noice it cornering with the windows open or top down.

Overall it is a great car I love it.

[bongko]

Originally Posted by M235SDCA

No, never had an issue with either one. Actually very few issues with the F23 at all and at about 55k now - even with the tuned engine. Not sure I would proactively change either one as they are a bit of a PIA - at least it was on my F10. Next thing I probably have to do the same trans fluid change you did.

One issue I've had is the hub clicking issue that needs the $40 friction disks from BMW that go between the rotors and the hubs. Did that about 18 months ago and the problem is back. Ugh! Now I'm just going to live with it. Only noice it cornering with the windows open or top down.

Overall it is a great car I love it.

I'm glad to hear this and hope that I can get to 55k with no major issues either. This is the first time I've heard of friction disks so thanks for the heads up. I'm not sure if I've heard any clicking noises when I corner but I haven't really taken any severe corners above 50mph as I feel my tires don't hold up well enough. More reading to do

[bongko]

So does anyone know where the aux radiator is on an F23? I'm assuming passenger side bumper, but isn't that where the oil cooler should be? Pic is of my driver side bumper area and the box is where I saw the aux radiator for F22's. One day I'll open the passenger side front bumper area...

On a separate note I was pleasantly surprised to find that I can open the hatch (arrow) to allow more air into the wheel well for brake cooling. I read some model years didn't have the hatch but luckily I found it.

I have driven fast on the freeway and didn't notice any issues with unwanted sounds or vibrations. Did it add some downforce? I'll let the experts debate that. What I can say is that opening the hatch doesn't help blow away any more brake dust as my front rims still get filthy very quickly after washes.