[franzrya]

Hey Everybody,

I recently noticed that when I start up my M235i, all of the exhaust comes out from the right tailpipe. I don't know if this is normal or not... After about 15 seconds or so, the car makes a noise and the left tailpipe begins to spit out exhaust. Does this happen on anybody else's M235i?

Also, I noticed that my breaks are already squeaking sometimes when I come to a stop. I've had the car for about a month and a half now... Should I be concerned?

Thanks a lot.

[Steven1077]

My 435i sounds like a tank when I start it from cold and only one pipe is open. after about a minutes it gets a lot quieter, I don't think the left side opens until I hit 4k rpm

[pikcachu]

It's normal... only one pipe is open at startup...

It's normal too... try bedding the brakes.... do a couple hard stops from 60mph-20 in a safe place and see if it helps

[DanG]

And if you drive in comfort only one tail pipe is used.

[Delnari]

The "brake" issue comes from improper break-in. You need to break the car in properly, or you will get problems like squeaky brake pads against the rotors.

Baby car for 50 miles when new like a 90 year behind the wheel. From 50-100 miles, in one outing, drive it like you are Grand Prix driver, hard stops, redline shifts, etc. From 101-1200 you can then drive like you intend to drive it the rest of it's life. High heat in the engine and on the rotors for a short period of them will seat everything proper. Some like the oil changed after 1200 miles, others think it's a waste of money; your call on that one.

[creepy coupe]

Originally Posted by DanG

And if you drive in comfort only one tail pipe is used.

Are you sure? That would make the exhaust sound louder in comfort.

[Steven1077]

I only have one open in comfort until I hit 4k rpm, and it's far from loud

[dwvcfii]

I've owned BMWs for 16 years now and work on my own cars.

Exhaust function is normal. BMW has done that for years to reduce low frequency noise below 2500 RPM (and idle, naturally). In the older cars some people would disconnect the solenoid that controlled the valve in the muffler so that exhaust would flow through both pipes all the time. The end result was usually a bit throatier idle.

As for the comment about bedding the brakes -- DO NOT DO THAT. This is a common misconception about OE brakes and "bedding" them in that manner is a good way to ruin them. BMW brakes are generally quiet, but they can squeak based on the specific formulation or if there is insufficient anti-squeal (high temperature grease) on the pads. Squeaking is more likely if the car's wheels have been washed with a pressure washer (ALSO A BAD IDEA) because pressure washing removes that grease.

[ska///235i]

I agree, u will find on the internet to drive hard and brake hard to bed in new brakes...that is total nonsense

The only ppl that do that are race cars as they need max performance from their brakes and they change te brakes after ever race.

Baby the brakes for break-in....apply light pressure (brake earlier at lights/stop signs) and slowly come to a stop. What you want is to smoothly even out the pad and rotor while applying the pad material on the rotor

Bmw should bed in the brakes at factory...less customer complains about noisy brakes imo

[Delnari]

Been driving BMW cars since 1982 (34 years) in Germany and USA. I always break in my cars this way including the brakes. Never had a one not seat properly on the rotor or squeal yet including my new M235i. My experience has worked for both my street and track cars!

Once you get a bad pad seat (grooved rotors) especially with metallic pads, the only way to cure is resurface rotors (or new ones) with a fresh set of pads. Many new motorcyclist make the same mistake to their new bikes as they will tend to bad seat even quicker than cars. Good thing for us, BMW covers rotors in the maintenance plan so if they don't stop squeaking you can have it performed under maintenance.

[Delnari]

Originally Posted by ska///235i

I agree, u will find on the internet to drive hard and brake hard to bed in new brakes...that is total nonsense

The only ppl that do that are race cars as they need max performance from their brakes and they change te brakes after ever race.

Baby the brakes for break-in....apply light pressure (brake earlier at lights/stop signs) and slowly come to a stop. What you want is to smoothly even out the pad and rotor while applying the pad material on the rotor

Bmw should bed in the brakes at factory...less customer complains about noisy brakes imo

Have to call BS on this statement. Heat cycling the motor and brake pads, and even tires is the only way to have them properly set. But hell, what do I know? Or wait, I have experience

[ska///235i]

Originally Posted by Delnari

Have to call BS on this statement. Heat cycling the motor and brake pads, and even tires is the only way to have them properly set. But hell, what do I know? Or wait, I have experience

I dont have 30 year experiance but I do have 20 years

Try braking slowly/smoothly for a few miles and put your fingers on the rotor...you will get burnt, that being said you can also bed in brakes this way

[mankid247]

Originally Posted by ska///235i

I dont have 30 year experiance but I do have 20 years

Try braking slowly/smoothly for a few miles and put your fingers on the rotor...you will get burnt, that being said you can also bed in brakes this way

I agree with you, they can call BS if they want but it says right in the manual under break in to use the breaks lightly for a like a chunk of the 1200 mile break in.

[mjposner]

Not just fpr older cars:

[ska///235i]

Originally Posted by mjposner

Not just fpr older cars:

Whats the advantage of removing it? Just louder at all times?

[DanG]

Does removing it open both exhausts all the time?

[overcoil]

Where is the valve for opening and closing the second exhaust pipe, before or after the catalytic-converter?

[mjposner]

Yes it does and after, at the end of the car.

[overcoil]

Is the valve also an emission device used to heat up the converter?

[creepy coupe]

Originally Posted by notime

Is the valve also an emission device used to heat up the converter?

Yes, that's in primary function.

[overcoil]

Question,

Ordered my car (235) and the carrier has begun shipping the car as of July 3rd.
At this point I want to add the M Perf. exhaust. Is it too late for BMW to install at port of entry or at this point my local dealer will have to install it?

[creepy coupe]

Originally Posted by notime

Question,

Ordered my car (235) and the carrier has begun shipping the car as of July 3rd.
At this point I want to add the M Perf. exhaust. Is it too late for BMW to install at port of entry or at this point my local dealer will have to install it?

In the UK it's a dealer only install. I've also heard BMW are out of stock at the moment?