[kern417]

Originally Posted by Supr3me

I'm curious about how the vacuum filler technique works exactly.


When I upgraded my turbo I did not use the vacuum filler technique and ever since then it's driven me crazy to think there might be air gaps in the system. I've driven thousands of miles and kept an eye on the coolant levels and they're very stable. But still, I wonder....

I have an appt at the dealership on Thursday for something unrelated - can they hook up the vacuum filler and quick check to see if it needs more coolant? Or would it require a full flush and fill?

Maybe a dumb analogy, but kind of like how opening a soda causes all the carbonation to rise up. Creating a pressure differential in the system forces the air to the top and pushes the coolant into all the passages, past the thermostats, etc. The only thing is that the pump running does all the same work and over time the air will come out on it's own, even if it is trapped somewhere.

[Supr3me]

Thats helpful thanks. I had to believe that daily operation would work it out eventually too but sometimes the stuff in forums can make you paranoid lol

[cfm56d7b]

Originally Posted by cfm56d7b

Adding more information to this thread.

My car: 2017 BWM 440i GC. 29.1K miles.

Started losing coolant in September 2019. The dealer replaced the main tank reservoir cap (a known issue) after finding dry white residue under the cap. Cold and hot pressure test revealed no leaks.

Coolant loss (albeit slow) continued. The vehicle was brought to the dealer in early July 2020. Again, cold and hot pressure test revealed no leaks. I escalated to BMW NA requesting turbocharger be inspected before the warranty expires in September. Waiting for a response.

My local BMW dealer contacted field engineer to follow up on the reported issue (see below) that slow coolant leak was addressed by replacing the turbocharger. No response. The dealer installed tamper proof seals under coolant reservoir caps and asked me to return if low coolant warning appears.

Note of interest:

bayern68 based in France reported that "turboloader changed yesterday on warranty after low coolant message at 12k miles. According to the mechanics, turbo was leaking coolant water, but only internally, that's why no water leakage under the car. Water evacuated through exhaust pipe. Although the leak was very small. Dealer also said it's a known issue on B58 2016 production."

https://f30.bimmerpost.com/forums/sh...1324221&page=5

Bump.

Hoping bayern68 will see this message. Would be grateful for a copy of the repair invoice.

[me90]

Not sure if this is helpful or not but I had my turbo replaced and have had no coolant issues since. Though technically it wasn't a coolant leak that lead to replacement of the turbo.

I bought my '16 CPO last year out of state and drove it home. Car had low coolant light on when I bought it but techs filled it prior to me leaving the dealership. An hour or two later on the drive home, low coolant indicator again. Monitored temps and stopped at a dealership in the next town. Tech said he put a very small amount of coolant in and warning went away. I don't remember if I got any warnings on the rest of the drive home but it definitely remained an intermittent issue after I got home.

Though I was still under warranty, I didn't bring it in until I was due for an oil change. I brought up the coolant issue at this time. High temp circuit was empty so they filled and ran pressure test but no issues detected. However, upon routine inspection, an oil leak was noticed to be coming from the turbo. They ended up replacing the turbo.

This was between Christmas and New Years last year. In that time and roughly 5k miles since, I've not had any coolant issues. So, despite the turbo not actually being indicated as the problem with the coolant loss, the new turbo appears to have resolved the issue.

Not sure if this helps you cfm56d7b but the invoice references SIB 11 15 16 as to what lead to the turbo being replaced.

[B58togo]

5k miles isn't nearly a long enough sample set to indicate the turbo made a difference. I didn't get the initial low coolant warning until 19K.

[me90]

True, the turbo could have some flaw that is prone to leaking and it could take thousands of miles to get a new one to leak again but considering I would get the indicator light after a hundred or so miles, I think 5k is enough to say that the turbo was the cause of the leak. Again, there could have been something else causing the coolant to disappear but the only thing that I know of to be replaced within the engine since I bought the car was the turbo and I've had no coolant issues since.

[cfm56d7b]

Originally Posted by me90

Not sure if this is helpful or not but I had my turbo replaced and have had no coolant issues since. Though technically it wasn't a coolant leak that lead to replacement of the turbo.

I bought my '16 CPO last year out of state and drove it home. Car had low coolant light on when I bought it but techs filled it prior to me leaving the dealership. An hour or two later on the drive home, low coolant indicator again. Monitored temps and stopped at a dealership in the next town. Tech said he put a very small amount of coolant in and warning went away. I don't remember if I got any warnings on the rest of the drive home but it definitely remained an intermittent issue after I got home.

Though I was still under warranty, I didn't bring it in until I was due for an oil change. I brought up the coolant issue at this time. High temp circuit was empty so they filled and ran pressure test but no issues detected. However, upon routine inspection, an oil leak was noticed to be coming from the turbo. They ended up replacing the turbo.

This was between Christmas and New Years last year. In that time and roughly 5k miles since, I've not had any coolant issues. So, despite the turbo not actually being indicated as the problem with the coolant loss, the new turbo appears to have resolved the issue.

Not sure if this helps you cfm56d7b but the invoice references SIB 11 15 16 as to what lead to the turbo being replaced.

Many thanks for SIB number!

[jbb2388]

What are you guys using for coolant to top off? I bought my 2016 340 in april of 2019 with 32K on it. I've now just gotten my 4th low coolant warning message w 71K miles on it. The few other times i've just topped off with water because the owners manual of course doesn't spec coolant for it. Which has undoubtedly diluted the protection.

[weehe126]

Just get a gallon from the dealer. Hope you are using distilled water to top off.

[jbb2388]

Originally Posted by weehe126

Just get a gallon from the dealer. Hope you are using distilled water to top off.

Yes, purified. Same as distilled. Not interested in trekking to the dealer and paying $30 for a gallon of it.

[weehe126]

Originally Posted by jbb2388

Yes, purified. Same as distilled. Not interested in trekking to the dealer and paying $30 for a gallon of it.

Purified is not distilled, at least in the US. So just be careful. Check FCP or ECS then, but I doubt they are cheaper than the dealer.

[F30_Paul_]

Hey guys

I started up my 17 340 not long before I am writing now and got a coolant low message

Turned the car off and back on and didnt get the message again

Turned it off, ran into the store, and back on and still no message

Whats going on here? Worth running to the dealer?

[jackstrath]

Originally Posted by F30_Paul_

Hey guys

I started up my 17 340 not long before I am writing now and got a coolant low message

Turned the car off and back on and didnt get the message again

Turned it off, ran into the store, and back on and still no message

Whats going on here? Worth running to the dealer?

Worth taking the 30 seconds to pop the hood and manually checking the coolant level surly

[F30_Paul_]

Originally Posted by jackstrath

Worth taking the 30 seconds to pop the hood and manually checking the coolant level surly

Yeah I shouldve before it got hot

[G.Newt]

Originally Posted by jbb2388

Yes, purified. Same as distilled. Not interested in trekking to the dealer and paying $30 for a gallon of it.

Big yikes.

[paulb15480]

FWIW these are my experiences with coolant "consumption" on the B58 engine. My story begins with my 2017 340i. Throughout the entire time I owned the car I had to periodically add coolant to both the low temp and high temp circuits. Following the forums this appears to be a feature of this version of the B58 with a widespread number of instances being reported, and that is just representative of the owner population that participates in forums like this. Rather than being too concerned about it I just kind of accepted it as the way it was for whatever reason since it seemed to be so widespread and all of the dealer attempts seemed to never really identify a source for the consumption. I just kept coolant in the garage and periodically topped up both reservoirs. I had the car from new until it had 51,000 miles on it and the coolant consumption rate remained steady over the entire time I owned the car. No evidence of any external leaks anywhere and I always had oil analysis done at every oil change with 0 coolant being detected in the oil. In May of this year a driver turned left in front of me at an intersection and the car was totalled. (Very sad day, but no injuries, thank you BMW). In my time in owning the '17 I probably added 1 gallon or more of coolant spread over both cooling circuits.

I replaced the car with a 2020 M340i after waiting for 3 months for the car to get built (thanks to the COVID joys). I now have over 5000 miles on this car and it has used absolutely zero coolant, and I mean absolutely zero out of either reservoir. This car has the latest "version" of the B58 in it obviously and something is definitely different. Could it have been the turbo on my 2017, who knows as I didn't really pursue it and once again kind of looked at it as a feature. If it was the turbo, I would have expected the level to only drop in the low temp cooling circuit which I believe covers the turbo and intercooler. The high temp circuit covers the engine itself and the two circuits are not connected. And yet both consumed coolant. Nothing in the oil, nothing showing externally on the engine.

Is this information useful, perhaps not, but it is at least mildly interesting, at least to me.

[cfm56d7b]

Reviving this thread.

Anyone with B58 engine still slowly losing coolant?

[FalconAus]

Experienced very small loss with white residue on threads of large reservoir.
Applied a tiny smear of silicone grease to the inner bore of the hole where the
"O"rings seat. Have done about 7000km. since with absolutely no loss of coolant and no white residue evident when cap removed. Cap was still firm to unscrew but not ridiculously tight like it was originally when exhibiting the leak.
Hope this may be of some help.

[M140_BCS]

Originally Posted by FalconAus

Experienced very small loss with white residue on threads of large reservoir.
Applied a tiny smear of silicone grease to the inner bore of the hole where the
"O"rings seat. Have done about 7000km. since with absolutely no loss of coolant and no white residue evident when cap removed. Cap was still firm to unscrew but not ridiculously tight like it was originally when exhibiting the leak.
Hope this may be of some help.

I did the same 18 months ago and had zero coolant loss since.

[cfm56d7b]

Refreshing this thread.

Anyone with B58 engine experiencing a coolant leak?

[kern417]

Originally Posted by cfm56d7b

Refreshing this thread.

Anyone with B58 engine experiencing a coolant leak?