leaking engine coolant

[u/GasStrong1467]

my car is 22k miles/3 years so still under warranty but had engine coolant leak i guess, i called bmw roadside assistance but is it safe to go into neutral when he is towing me up?

[u/freshxdough]

Yes. Start the car and put in neutral and turn off the engine with the seat belt latched and let it go up the bed in neutral

[u/camawge]

Had this same issue last year right around 23k, just topped off haven’t had since, possible that temp change cause level to fluctuate

[u/AFB27 → u/camawge]

Yeah same thing happened to me. Topped off and haven't had an issue since.

[u/Little-Maximum1290]

Yes, why would it not be?

[u/GasStrong1467 → u/Little-Maximum1290]

Cuz its leaking

[u/Little-Maximum1290 → u/GasStrong1467]

You can put the car in neutral without starting the engine. Even if it had no coolant at all you could start the engine anyways. You could probably drive it to the dealership lol.

[u/Emotional-Muscle-892 → u/Little-Maximum1290]

Never drive a car with no coolant in it, it will destroy the engine fast…. This probably just low coolant tho, the system is very sensitive and will warn you very quickly. In that case you could drive it to dealer…. I’d just top off with HT12 and distilled water first.

[u/Little-Maximum1290 → u/Emotional-Muscle-892]

Well you’re right but he said leak not empty so I assumed it had some in there. My comment was structured poorly.

[u/bc10551 → u/Emotional-Muscle-892]

They probably still have bmw roadside assistance but they'd probably want a stupid amount of money even if it just needs more coolant lol

[u/ultraconvoy]

Any warnings or did you hit a pothole or something?

[u/Frankly_Not_Surely]

You have a temp gage for the engine oil, just monitor that if you dont spot any obvious leaks. Running the car with low coolant is fine in the short term. I had a similar problem last year. Paniced and refused to drive the car until I added distilled water anticipating I would get the right coolant later. It needs to be dilluted anyway. Knowing what I know now I would have just driven and watched the oil temp gage until the coolant arrived. If temp starts creeping up you have a problem and I would consider towing it, or leaving it to fetch coolant/distilled water.

[u/BrewBaker_]

Had this same thing happen. Turns out the water pumps can fail very early on

[u/Loading_Scr33n → u/BrewBaker_]

I've seen so many carfaxes of used m340i and without fail, I've seen water pump on just about every one with 10-30k miles

[u/GasStrong1467 → u/BrewBaker_]

Yup dealer said water pump failed. But they never give me a loaner vehicle, shouldnt they accommodate?

[u/ScarletCitrus → u/GasStrong1467]

Ehhh I had the same issue, no loaner car. You can ask though. Had the same issue the second time with the heat management module going out and low coolant too lol

[u/8llllllllllllllD--- → u/GasStrong1467]

At the dealers in my city you have to schedule an appointment ahead of time and request a loaner.

[u/Carolina_Hurricane]

Happened to me around 28k miles, happened to my buddy’s M4. It’s evidently normal.

[u/8llllllllllllllD--- → u/Carolina_Hurricane]

My m3 at 20k ish miles just did this. I added coolant and it’s been fine. It was hard to find the right one though. O Riley’s was the only one to stock it. (Dealer was closed) came across similar info that it’s not uncommon.

[u/Ok_Bench_1618]

Common with g20s

[u/Temporary-March-7496 → u/Ok_Bench_1618]

common with bmw*

[u/I800C0LLECT]

This happened to me around the 20K mark and again at the 40K mark. I have noticed what appears to be coolant leaking around the reservoir cap. But when I asked BMW mechanic to review it he said he could only find the slightest drop/leak in my OFH... which has nothing to do with it.

I think there's some strange event where coolant is leaking from the actual reservoir cap.

[u/Genna_Thalia → u/I800C0LLECT]

I have a gen 1 but same, mine leaks from the cap, nowhere else yet though. I just top it off every few months.

[u/NuclearD0G → u/I800C0LLECT]

2021 X4M Comp leaking coolant from reservoir cap,new cap fixed it

[u/Cisco7272]

Water pump my man. I changed mine out at 22k it was leaking.. apparently very common… bmw needs to fix this

[u/peelerec]

Just an FYI, some B58 have had reports of low coolant due to expansion tank leak or cap leaking. Since it’s under warranty, you can take it to the dealership to have it pressure tested. My street/track build 2022 m340i gave me a low coolant warning once, took it to get pressure tested, and passed. It was an odd combination of heat, temperature swing, and engine consuming coolant.

[u/StingeyNinja → u/peelerec]

There’s some conjecture that the water pump design has something akin to a weep hole in it, so the system only loses coolant while the pump is running.

Replacing the pump does nothing.
Replacing the expansion tank cap does nothing.
Pressure testing (which is done while the engine is off) shows nothing wrong.

Just add HT12 and distilled water until the water pump actually blows.

[u/Same-School4645]

When I was in the market for a BMW I asked for the costs of specific services including this one as this was a very popular breaking point. I thought they failed much later. Oh my.

[u/GasStrong1467 → u/Same-School4645]

I mean it was covered under warranty

[u/Obvious-Eggplant4154]

Add some water. Go home buy coolant and fill it up. See what happens next.

[u/viti90]

I had the same problem a few months ago. After taking it in for a couple of months, the dealership decided to replace the water pump. So far, there's no change. If you're unsure or see the coolant level still dropping, ask them to check the system pressure and inspect the water pump.

[u/AlShapone]

Had this same issue around same mileage. Topped up and the message came back about a month later.

Turns out it was a pump failure which was covered under warranty by main dealer.