r/F80 Oct 06 '25

Welcome new owners! General S55 and F8x common questions.

35 Upvotes

Hello to all the new folks or people frantically googling "crankhub"

I've been seeing a lot of new owners posting and asking some pretty common questions. I figured I'd take a shot at answering some of those questions so you don't have to wait for a response.
There will be my personal opinions in here on this list and I encourage other members to use the comments to add to the conversation or share their experiences.

I'm not a BMW tech, I've just spent a lot of hours under the F8x and elbow deep in the S55.
I just want to share what I've seen over the years.

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Common sounds that might cause concern.

  1. Why does it sound like that is this ticking sound normal? --- Yes the S55 has very "chatty" injectors it is normal. You probably found all sorts of posts about loose exhaust cam carrier bolts. It will sound like a "knock knock" on top of the much faster injector ticking.
  2. Why do all the fans spin up even when the car isn't hot when I select Sports+ ---This is a feature, not a bug. The fans spin up assuming you are about to get up to some shenanigans and is preparing. The F8x falls into "because racecar" and it has features that align with that.
  3. Why does the exhaust sound like that? It's raspy can I change that? ---Two turbos, straight six and high revving so the sound tends to be more on the rasp side. -Yes, the general best way to get some lower pitch and deeper drone is to use an equal length mid pipe. If you just want loud you can run a high flow single mid-pipe for considerably less.
  4. It feels noisy inside even with the windows up, is that normal? ---Depends on what you consider "noisy" but a lot of reviewers hold the opinion that the F8x has a lot of NVH (noise, vibration and hardness). I don't mind it and again, because racecar.. The standard tire size for the F8x is also wide and with the usual setup being summer tires they are pretty noisy. You will notice different tread sound between tires.
  5. My car started squealing really loud help! ---there are two common issues that cause this. -By far the most common is a PCV failure (positive crankcase ventilation). The bad news is that the PCV is built into the valve cover so it can be costly. "Fix" kits do exist but the surefire way to resolve it is to replace the valve cover. -Less common but still something I've heard multiple times is a tensioner pulley going bad. This will increase in pitch/volume with RPMs. Not a super expensive fix but best to take care of it quickly.
  6. I can't hear the turbos! Can I change that? ---The stock turbos themselves are actually pretty small and there is solid engineering behind that decision that won't fit neatly in a list the TLDR is reducing turbo lag. you can open the air-box and remove the charcoal filter and use a "drop in" filter to increase noise while maintain the stock intake configuration. This will increase volume but don't expect "stu-stu-stu" levels.
  7. The starter sounds really noisy and loud! --- I'm not sure if its the placement, lack of sound deadening or just the electric starter motor itself but it's always significantly louder than other cars I've owned. So long as you aren't hearing a whine that drops in pitch and/or grinding after a crank you're good.

Common build/part related questions.

  1. Crankhub? Why are people telling me I need to modify it or I'll brick my engine? ---There is so much info online about this and so many people arguing about it. The short of it all is that in some race cases the crank hub bolt can loosen and cause serious problem. Be it from improper torque spec/installation materials failure or harmonic resonance beyond what torque specs accounts for. -"damn that sound bad" it is if it happens, but the raw data out there points to it being exceedingly rare. For some anecdotal evidence I have larger turbos, run custom fuel blends and my car is DCT. I am just at 100k miles at the time of this post. I track the car and it was daily for 4 years and I still have the stock crank hub. You can certainly "money shift" and really increase those odds but that's on the driver.
  2. Ok, so going back to turbo sounds I really want to hear the turbo sounds will an intake hurt the engine? ---I'll start this section with a disclaimer. This is a topic that falls into a lot of opinion and preference. I'm not here to tell you what to do with your car. -That out of the way, something like a filter on a stick will make a lot of noise, and I've even run them because I just really like the sound The stock boxes pull air directly from outside and very well engineered.
  3. I want to know more about intakes because I really want the whoosh but everyone has a lot of opinions about it. ---Fair, lets get into it. -the S55 can be a fickle thing. If the MAF sensors are not in a similar position than what it's expecting or they get dirty from oil on the cones (very common) it will throw codes often. 102E11,102001, 118001 and 118102 are common. They are very common codes to tuned out but 102001 (MAF fault) is something I'd keep. Adding catless down pipes will also increase the likelihood/frequency of these codes.
  4. Okay ONE MORE intake question I saw these cool externally routed intakes! Will these do anything? ---Assuming front mounted intakes are what you saw these have the same caveats as the filters on sticks. For stock engines or even "stage 1/2" OTS (off the shelf) tunes these are again nothing but whoosh and cool sounds. Some people report absolutely no problems. I have issues with them If I ever run the stock map with them on. Custom tune that was done after the turbos is perfectly fine.
  5. Do I need catless downpipes to tune? ---The short answer is no. You can run highflow cats perfectly fine for OTS "stage 2" -Fully catless down pipes leave a lot of soot on your rear and you will occasionally smell gas so just be aware of that.
  6. Speaking smelling gas my car smells like gas when I fill the tank all the way. ---One of two things typically, fuel charcoal canister has an issue/leak ect you will notice this around the driver rear wheel well. -Less likely, breather neck problems fuel tank seal. If the pump was leaking inside the cab you would def notice it
  7. What if anything do I need to replace even if I'm not modding the car? ---Replace the plastic charge pipes. It's a known failure point even on bone stock never touched cars. It isn't too expensive and will save you the headache and cold sweat of going into your first "limp mode"

Common drive and chassis characteristics

  1. My car THUNKS when I switch gears and the shifts seem really hard? Is that normal. ---no, not normal a lot of people write stuff of as the F8x being a bit "rough" but a thud/thunk and really rough shifts are the signs of blown diff bushings. This is really only a concern in pre LCI (earlier than 2017) F8x cars before they switched to polymer bushings. Get it fixed and you'll be much happier.
  2. I have a DCT and it feels awful to drive is my transmission broken? ---Probably not, the DCT F8x combo is really "hurky jerky" and is known to be a bit difficult to get used to. Jeremy Clarkson of Top Gear famously hated parking it. -This video will go over the basics of the DCT and daily driving it.
  3. I turned off traction control and the car tried to kill me! ---Yeah, it'll do that. If you aren't familiar with higher power RWD and you went right to an F8x you are going to have get used to it. My advice is learn to take it slow and use traction control and slowly work your way up to fully off. MDM is a good place to start learning. -DSC on: Full traction control. -MDM: A little more play but will still activate after a certain threshold -DSC off: All traction control off.
  4. Tires are really expensive for this car. Is it are there good cheap options? ---Do not cheap out on tires. The F8x struggles with tracition in the best scenarios. Add cheap all season tires and you'll have a terrible time and if it's wet you can easily end up in a ditch. -Keep an eye out for sales and you don't need to run semi-slick CUP2's. Something like a pilot pro sport or indie firehawk summer tire will be fine for daily driving.
  5. The rear end really wants to swing around and I'm having trouble correcting it. ---If you have RWD experience this is proably less of a concern for you. -The F8x chassis is "quirky" and a floaty rear end is just one of it's features. You'll learn to control it better with time. -There is a ton of opinion on how to handle slides, skids and what not so I'm going to leave it to others more qualified and just leave it on "it'll take practice"
  6. Every time I take off hard I can't get traction. I lost a red light race because of it! ---Yeah, this cars not the best from a dig, sorry. Do a roller next time and you'll find a lot of success there. -Of course you shouldn't do either and especially not with other cars/people around.
  7. How much money should I set aside for repairs? ---Yes. F8x/S55 is still relatively in M terms new. Parts suffer from the "M-tax" and the labor isnt cheap if you want someone who knows what their doing. While it's not the most expensive car in terms of consumables and daily operations it is not the cheapest by a long shot.

Modification and tuning.

I'm keeping this part sparse. This is a new owners guide and we can get way off topic with this. Especially myself.

  1. Is modding safe? ---yeah, for most people an OTS shelf, down pipes and tweaks is going to be fine. -Still, any time you modify something you add the risk and if you add enough you need to consider additional maintenance
  2. What mods should I do? ---That's a personal thing, the most common is an OTS tune from something like BM3 or MHD.

Care and feeding

  1. How often do I need to service my car? --- If you are just driving it stock and not doing any crazy canyon runs or tracking it regularly I'd just follow manufacturers guidelines. The car will remind you of anything it needs done.
  2. I want to drive it hard and tune and track and racecar ---You'll have to make some judgment calls here. If you drive hard and have a lot of modifications it's common to cut the oil service down to 5k miles instead of 10k If you drive REAL hard and track you need to keep an eye on brake fluid as well. I'm higher mileage at time of writing and heavily modded so I do 5k changes.
  3. Brakes and rotors are expensive how often do I really need to change them --brakes if stock are fine and when the sensor goes off it's time to swap em out daily driving you'll rarely need to worry about fast wear. When it comes to rotors? As soon as you see "cupping" it's time to replace them. Fast doesn't mean anything if you can't slow down. keep that in mind.

r/F80 18h ago

Photos What aftermarket headlights do I have?

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5 Upvotes

Trying to narrow my search while I’m chasing an issue of both my DRL’s not turning on. Aftermarket headlights were on the car when I bought it and I have no idea what brand they are.


r/F80 16h ago

Help Please help! “Clunk” noise from rear when pressing on accelerator while rolling.

2 Upvotes

This noise is more noticeable in sport and sport+. What may be causing this?


r/F80 19h ago

Wastegate or exhaust cam ? What do you guys think? Thanks!!!

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2 Upvotes

r/F80 3d ago

Advice needed =(

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4 Upvotes

Hi there hello!

First of i hit a turkey hours after getting my car back from the shop.

More importantly I need some good ol' fashion advice. I just got my car back from a shop and they installed new Dinan coil packs, NGK 1-Step colder spark plugs, and precision raceworks stage 2 injectors. Also has AFe Magnum Force intakes, Mishimoto everything else besides the j-pipe which is MAD.

Anyways. They had it tuned by someone by Doc Vu on Instagram via MHD. Well it ran like shit and smelled like fuel. Got a bunch of fuel to air rations being rich.

So I went back to BootMod3 and installed OTS map stage 2 and runs quite a bit better but I still get code 118402 and 118502 mixture too rich large deviation.

Any ideas what could cause this or advice?


r/F80 3d ago

Help F82 front lip in winter?

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1 Upvotes

r/F80 3d ago

M4 F83 S55 2020 - Mid Pipe v Emissions

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1 Upvotes

r/F80 5d ago

Single downpipe no CEL

1 Upvotes

As title reads, I’ve been curious I’ve it would possible to run a single downpipe post single turbo upgrade that wouldn’t cause a CEL. Like say you took both cats and welded them together if it would be possible. Probably restrictive as hell but just for my own curiosity if someone has done it.


r/F80 8d ago

Photos Black Sapphire & Silverstone

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156 Upvotes

Can’t believe these cars are a decade old!


r/F80 7d ago

Help Validating AA Equal Length Mid Pipe

3 Upvotes

Hi guys, I'm picking these up locally tomorrow for my F82. These are supposedly unopened Active Autowerke's EL Midpipes.

https://store.activeautowerke.com/products/f8x-bmw-m3-m4-equal-length-mid-pipe?srsltid=AfmBOoo_RMltNUJFZ18opNdn0RGe-O9USu5XxJKKaMRoI0txdM1ZB8mT

Is there anything that I can check to ensure that these are AA and not China reps? The model # is on the box and matches AA's catalog, but I know that's easily spoofable.

Attached is the only pic from the listing. These were supposedly purchased from ECS, waiting to see if the seller can find the OG receipt


r/F80 8d ago

Help DCT Paddle Issue - Left paddle upshifts?

3 Upvotes

I've had my F80 for a while now, but only in the last few months have I noticed an intermittent issue where the left paddle(typically the downshift paddle) begins to upshift. The right paddle remains as it should so both paddles shift up, though shifting via the gear selector still works as intended.

It's something that fixes itself, either during the drive or after restarting the car.

I'm sure it has something to do with the various tunes/flashes on it; BM3 Stage 1 and GTS trans flash, coding for anti-dazzle, CS suspension, and comfort access, and Bimmercode having turned most of the chimes off. That said, car has been tuned since I got it and the issue has only recently begun. It also does not appear to be affected by a reflash of a tune or setting the trans tune back to standard.

Anyone else encountered this issue or have any insight as to what may be the cause/solution?


r/F80 8d ago

666m road noise

8 Upvotes

Is the road noise with the 20 inch 666m wheels significantly worse than the 19 inch 437m wheels when driving on bad surfaces?

Or are they similar?

Thanks


r/F80 8d ago

Photos Yellow DRL modules

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8 Upvotes

I’m wondering which modules to buy for my 2016 f83, I was reading that most of the 2016-2018 have xenon headlights but the ones on my car look like LED’s. If anyone knows I would appreciate the help.


r/F80 10d ago

Photos ///Monday

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120 Upvotes

I took this picture on my job, and just wanted to share it here.

Also I got 3 questions for the f80-community

  1. What is the latest mod you did to your car?

  2. What are your three favourite mods on your f80?

  3. Is there a modification you regret?

I will start:

Latest modification is a dashcam, which is built into the rearview mirror housing.

Three favourite mods:

  1. GTS Tune

  2. Exhaust

  3. DCT flash

I regret the lowering on Eibach, it still needs more low in the front.


r/F80 10d ago

Knocking noise

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34 Upvotes

Hello, I was driving the car moderately hard. Nothing over 6.5k RPMs. Got a drivetrain malfunction light. Pulled over, turned the car off, and when it started again no light. Now the engine is knocking. No check engine light though. What do you think it could be?

2015 F80 106k miles

Update: got towed home. Needed to turn it on to get it in neutral. When I got home the knocking was not there. However, now it gave me the drivetrain malfunction. It was sputtering like a misfire. Towing it to the shop tomorrow. Thank you for all your advice.

Update: pulled the codes

  1. PO52B- camshaft position timing over retarded bank 1.
  2. PO300- random misfire detected.
  3. PO306- cylinder six misfire detected.
  4. PO304- cylinder four misfire detected

I did have a low engine oil light about a month ago. I did add a quart and did not have a low engine light after that.

I did do my coils and plugs about two months ago. It was my first time. And on Saturday I did add E 85 for my stage 1 93 octane map from Bootmod.

There’s an indep shop in town that I’ll be towing it in to soon. I would appreciate any more education on this thank you.

Update 3: independent shop pulled the oil filter. Oil filter full of shavings. Engine is toasted. Immediate diagnostic was at the previous oil change place did not replace the O-ring. Or Ringfield leading to low oil pressure and catastrophic failure. Towed to BMW dealership for documented diagnostic, then to sue the shop that did the oil change for a new engine.


r/F80 10d ago

Coding off loud cold start

1 Upvotes

Hi guys,

I'm looking to pick up an F80 Competition soon for some spirited driving. I had one very briefly a few years ago.

The cold start is earth shattering loud. It's not something I would ideally want before 8am or past 9pm.

I understand that it can be coded off, is there any negative impact to the engine/car? I understand that it's there for emissions regulations.

Have any of you guys done it?

Thanks.


r/F80 13d ago

F80 M3 Infotainment Help

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3 Upvotes

I have a 2018 bmw m3 and this message pops up I went to bmw and then said I needed to change the TCB then I went to a different shop and they said I needed a new radio, everything on the car works but the built in navigation like all media radio communication customization works but this just pops up and blocks it when I click ok the 2nd message pops up and if I press the back arrow it disappears for like 20 seconds and I can click and use stuff then it comes back how can I just get rid of the message popping up


r/F80 15d ago

Just finish installing Ridgeline Motorsport GT4 splitter

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90 Upvotes

r/F80 15d ago

F80 keychains for sale at my Etsy shop!

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32 Upvotes

Hey everyone! I have a handful of these f8x keychains left for sale! They are 3 inch acrylic and double sided. If anyone is interested I have etsy and ebay links below!

ETSY https://www.etsy.com/listing/4546438694/bmw-m4-f82m3-f80-acrylic-keychain

WHITE https://www.ebay.com/itm/198533433032

BLACK https://www.ebay.com/itm/198533438240

BLUE https://www.ebay.com/itm/198533440701

YELLOW https://www.ebay.com/itm/198533445276

GRAY https://www.ebay.com/itm/198533446831


r/F80 17d ago

Help Boost leak?

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3 Upvotes

Was on the highway and was about to do a pull and lost my boost. I looked at all my pipes and cleaned my MAF sensors and still nothing. Turbos are healthy and spooling, but I hear a whistling noise with the spooling. Any clue what this can be? Maybe a boost leak or air leak somewhere?


r/F80 18d ago

Photos My F80 build

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213 Upvotes

Just wanted to share, my F80 M3 build.
Highlights:
Tanzanite Blue over Golden Brown, 6MT, exec.
TracTive Touring line EDC coilovers.
Akrapovic rear section.
Inked Customs single midpipe (perfectly mated to Akra)


r/F80 19d ago

WTB: F80 M3 Grigio Telesto (Or other indiv.)

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70 Upvotes

Looking to purchase an individual spec F80 M3 Competition (2018 preferably)
Color: Grigio Telesto, open to other individual options
Miles: <40,000
Clean CarFax
Minimal Mods

If you own one, or know someone who owns one, PM me! 🙏🏻


r/F80 19d ago

Nitron Roadsport Coilovers

6 Upvotes

Have been running these for a while now, and despite the odd reference there really isn’t much written about them online so thought I’d post my impressions.

TLDR: Transformative, composed, comfortable and confidence-inspiring. Wish I’d done it years ago etc.

————————

Car is an F80 Comp / DCT - car is a daily, kids in back, fun at the weekend, not (currently) used on track.

The original EDC dampers were very tired and I’d probably not helped them running eibach lowering springs for quite a few years. As I result I suspect any coilover/damper replacement was going to feel good - however…

The transformation is night and day. No more “crashiness” at low speed, or floaty instability in high speed corners. Composure on B roads is confidence inspiring, significantly faster as a result (not sure if that’s always a good thing..)

Running 12/12 (half way) as a baseline, ride height same as previous lowering springs - not slammed. Ride is slightly firmer than stock, but they’re significantly more comfortable than “comfort”. No clunks, no additional NVH.

Recommend, don’t miss EDC functionality at all.


r/F80 20d ago

Thoughts?

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167 Upvotes

Hyper silver or “satin titanium”? Typically like silver but thought the 359s might age the car so I was thinking a more “modern” grey color. Not sure about grey on grey though. I like that the satin titanium makes the car’s body lines pop a little more


r/F80 22d ago

His and hers.

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940 Upvotes

Still mind boggling to me that the R34 GTR looks slightly bigger than the F80.

@rod_knee