Howdy- just signed up for Bimmerpost. I can change light bulbs on my car but I say that to say this…I really don’t know squat about cars, let alone my gorgeous M40 that is slowly falling apart and I’m hoping for that to not happen! So here I am..with a desperate interest in learning, at least, about my model in order to prevent catastrophic failures.

I have several things going on:

1.) around September i blew my turbo pipe, refused to pay the $1800+ the dealership wanted, and found a mechanic at work I trust who has worked on bmw’s before. I say “trust” even more after he told me there was oil in the charge tube and the fkng dealership never even reported that to me. Nope! I will never return to a bmw scam dealership in my lifetime, so help me, God!

2.) So charge tube got replaced, but after that I received a P0440 EVAP SYSTEM error code on mechanic’s diagnostic. Out of (5) error code possible causes, (3) were related to faulty gas cap. Bought a new gas cap but check eng light returned, and will randomly go off, but come back on. Mechanic thinks it could be a bad purge solenoid? I also *on occasion* smell burning or exhaust inside the car while driving, most likely related to this issue.

3.) Recently, i’d say the last 2-3months only since November, I got a low coolant level notification on the car, i had some coolant, i maybe put in 12oz-16oz? Was fine, but it came on again in December, so at that point i knew i might have a small leak somewhere. Put more coolant, everything fine up until yesterday and I just received the warning again. I go to put coolant in a few hours ago, holy crap coolant everywhere. It is sprayed and splashed all over the expansion tank? I think it’s called? The round tank you put coolant in- i see dried/baked coolant all over hoses and remnants of puddles way underneath the motor on the cover, i see it on the side of my radiator. It’s a fkn crime scene in my motor rn and I’m embarrassed to even admit it’s this bad. It did not look like that a few weeks ago when I put coolant in it last time. I love my car and don’t want it to die!

There are so many simultaneous issues right now. For context, the car is a 2018 with 115k miles. I am certain it is due for a lot of work. Where do i start(besides obvious issues)?

Note: i call this man helping me ‘my mechanic’ but he is a coworker helping me out of pure goodness, on his own time, for a fraction of what i would pay anywhere, but i need to learn this shit on my own as it really sucks being a chick needing maintenance work on my car. It beyond sucks. I’m definitely interested in learning how to work on my car myself. Any helpful suggestions or advice would be greatly appreciated! Thanks in advance.

To me, it looks like coolant sprayed front to back, so maybe the upper radiator hose shown on left of first photo, or the plastic part of the radiator it connects to. The purge valve is probably easy to replace, if you know how to unlock the squeeze rings and is in the same area. Charcoal cans I've heard fail when owners pump more fuel at the station, after it clicks off, to "top up"

Thank you! Yes today while it’s still light out I’m going to run it until there’s enough pressure to hopefully see where the leak is. I’m driving my work beater car until these issues are fixed on my bmw. Fingers crossed it’s just a hose or fitting. Also planning on washing the motor out real good this next weekend, mostly because it just needs it badly, but will help detect any other possible leaks, too. As far as charcoal canister, no, I don’t add additional fuel past the auto shutoff, so possible it is the solenoid? Would the purge solenoid being stuck open cause the exhaust smell inside the car? Any good places I can get videos at other than youtube for locating and replacing this?

Exhaust smell in cabin on your n55 might be the low side of the engine valve cover leaking oil on to the exhaust or cat (right side of car, from driver perspective; left side of engine bay)

Will check that out, thank you!

Just got done with checking for coolant leak. It’s *at least* the radiator and possibly another leak lower. Could see fresh coolant leaking from upper side of radiator but then after I shut the car off a huge puddle formed under the car. It’s bad. Get to shop for parts now. That puddle formed within 3-5minutes.

This doc helped on my f25 n55.

When I did my rad, I used Nissens and it's fine three years later. When I did my valve cover, I used a metal one and it has a problem with bolts backing out. Maybe you can get the Mahle cover Some tips.

I am not sure since your n55 is newer than how mine works. You might just need to transfer over anything blocking the vacuum pipe to vacuum pump and two vacuum nipples above the likely oil drips. (labeled 2, 3, and 4):


Edit: This fuel pump replacement guide shows how to replace purge valve on page 4, and you should be fine skipping earlier steps. Youtube seems to have videos on testing whether it is faulty.

My X4 M40i developed a radiator leak on the left side. It leaked out of a seam at about 75,000 miles.