[cutnsew]

Dumb question, but have you checked the cap? I mean, like to make sure the seal is still good? I’m wondering if the cap is just barely bad enough that when there is a big temperature/pressure gradient it leaks/vents coolant fumes? Could always replace the cap to see if that changes anything.

[95wildtt]

Originally Posted by cutnsew

Dumb question, but have you checked the cap? I mean, like to make sure the seal is still good? I’m wondering if the cap is just barely bad enough that when there is a big temperature/pressure gradient it leaks/vents coolant fumes? Could always replace the cap to see if that changes anything.

Been thinking that same thing, and maybe it is designed to vent above a certain pressure?
The smell always seems to be concentrated at that location.
My wife's 2020 Macan does the same thing...

[corbs09]

I have checked the cap, they are strange caps but it seems fine with no issues. This is killing me though so I might just go buy another one as a test ha

[Edgar_FriendlyX3M]

Number 8 and 10 are both driver side items and I'm wondering if it's related to your issue. Don't know if the expansion tank has any venting (I imagine it would) so perhaps it's this?

[OttawaM]

Add me to the list having this issue. It’s been to the dealer several times for it already and they can’t find the issue. I don’t even have to drive it hard to occur - just has to be around 10mins or so driving around - even in winter time. Frustrated. Kind of embarrassing that a vehicle like this stinks of coolant constantly.

[corbs09]

Same here OttawaM... Between the squeaky brakes and the constant smell of coolant, it doesn't feel like I am driving a high end car ha. Not to mention the TONS of rattles in my trunk area.

Really hoping someone figures this out!

[Strick]

Mine started this on my road trip out to the Rockies this past winter. Now I'll smell it putting around town

[in2zion]

I assume you guys are losing coolant along with the smell. My 2022 has 7228k miles on it and experiencing coolant loss but I don't smell anything. I don't have a garage though.

Do you guys tend to warm up your engines about 10 minutes before driving? I notice about 1 cup loss in the engine and 1/2 cup loss in the charge reservoirs since 2K miles of short distance driving. Had it filled up at 5K at the local BMW dealer after noticing about 2 cups lost at that time.

Anyway, I would like to understand why this is happening. I am concerned that the dealer will say "This is normal".

[Jnat]

I know it's a different engine but my B58 had this exact symptom and there was no leak. I had to add coolant quite often. I changed both reservoir caps and the problem went away. Maybe try that, it's a cheap repair.

[in2zion]

Right, I heard about this. Did you see signs of evaporation on the cap or the opening of the reservoirs?

Since it costs $43 for both caps, I may try this route.

Originally Posted by Jnat

I know it's a different engine but my B58 had this exact symptom and there was no leak. I had to add coolant quite often. I changed both reservoir caps and the problem went away. Maybe try that, it's a cheap repair.

[Jnat]

Originally Posted by in2zion

Right, I heard about this. Did you see signs of evaporation on the cap or the opening of the reservoirs?

Since it costs $43 for both caps, I may try this route.

I thought I might have but i'll say inconclusive on the visual. What I can say is the new caps (ordered from FCP) fit i'll say tighter and i never added coolant again for the year after (eventually traded for this X3M).

[Skiddz]

Mine (2021 X4MC) has a hint of coolant smell after driving, too. It's only ever so slightly noticeable near the expansion tank on the left side. No drips, drops, etc. I'll be trying new caps for the hell of it

Edit: 07 Dec 2023: I changed the cap on the main system overflow tank (item 8 in the system diagram above) about a month ago. Prior to that, I could smell coolant when walking by the (left front side) vehicle after it had been driven and was full warmed up. Granted, it wasn't terribly strong (as noted in my original post), but it was definitely noticeable every time.

After changing the cap I can no longer smell it when walking by - but I can smell it ever so slightly if I stick my nose down there. It's actually funny because I had forgotten about the odor untill I saw the old cap on my toolbox a week or so ago.

YMMV, but that's how my story went

[Vasile97]

Originally Posted by Jnat

I know it's a different engine but my B58 had this exact symptom and there was no leak. I had to add coolant quite often. I changed both reservoir caps and the problem went away. Maybe try that, it's a cheap repair.

My car is with B48 and it’s seems like I have the same problem like you had. In almost 50,000 km I added around 500 grams of coolant and there is no any leaks but the smell of coolant under the hood persists after every trip.

So the question is, is that really was the problems with those two reservoir caps?

[Jnat]

Originally Posted by Vasile97

My car is with B48 and it’s seems like I have the same problem like you had. In almost 50,000 km I added around 500 grams of coolant and there is no any leaks but the smell of coolant under the hood persists after every trip.

So the question is, is that really was the problems with those two reservoir caps?

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