[Brad4fun]

Sorry if this topic been talked about before. This is the second time I have to do this, got me worried. Service guy told me this is normal for car to top off coolant. I said maybe for BMW is. He didn't like that at all. Anyway, hope this is "normal " for BMW.

Anyone have been through this? It's normal right?

My car is 540i xdrive 20018

Any input would be much appreciated

[Desmond79]

Originally Posted by Brad4fun

Sorry if this topic been talked about before. This is the second time I have to do this, got me worried. Service guy told me this is normal for car to top off coolant. I said maybe for BMW is. He didn't like that at all. Anyway, hope this is "normal " for BMW.

Anyone have been through this? It's normal right?

My car is 540i xdrive 20018

Any input would be much appreciated

Normal - look in your Owner's Manual. Buy some BMW Coolant off amazon or bimmerworld, etc.

On a long trip, I carry coolant and a quart of oil in the trunk.

[ztx84]

Its a known issue with the B58... I don't think anyone has a conclusive answer but equally it doesn't seem a serious issue. Some have reported leaking water pumps or hoses, or expansion tank caps that don't quite seal correctly, but there doesn't seem to be a consistent pattern. Mine loses a tiny bit every now and then, but the amount disappearing is miniscule (for now). I am intrigued to find out where it is going though!! It baffles me how liquid can escape from a supposedly sealed system and for this to be deemed "normal" but there we go!

[AP]

I'd just make sure you have it recorded with the dealer in case of issues that may occur later, especially if just the warranty has expired!

Worth using a torch to see if you can find any in the engine compartment. In my case it was faulty reservoirs (yes there are 2) . Tell tale signs were seen with a whitish residue beneath them.
Mine were replaced under warranty and no issue seen since.

[b74heavy]

Originally Posted by Brad4fun

Sorry if this topic been talked about before. This is the second time I have to do this, got me worried. Service guy told me this is normal for car to top off coolant. I said maybe for BMW is. He didn't like that at all. Anyway, hope this is "normal " for BMW.

Anyone have been through this? It's normal right?

My car is 540i xdrive 20018

Any input would be much appreciated

I have a 2019 540i. I have had the same problem. At 7200 miles I got a coolant low warning light. I carefully drove to the dealer. He filled up the High-pressure system and pressurized the system for 30 min and said that there were no leaks. Then told me that sometimes the factory doesn't fill the system all the way. I didn't believe them so I bought a quart of BMW spec antifreeze and went to the grocery store and bought a gallon of distilled water. I was ready for it to leak down if it happened again. So at about 14000 miles, I checked the antifreeze and it was down again. I mixed a batch of 50% antifreeze and 50% distilled water. So I followed this process again about every 5000 to 6000 miles. I now have 39000 miles on my 540i and the boil-off or leak has not gotten any worse. So my Service Advisor said not to refill it and as soon as the warning comes on again drive straight to the dealer to trouble shoot it so they can fix it. I am able to mix and install the antifreeze so I guess I will quit fighting with them. I have had them leak check it 2 times and they found no leaks. There is a very good BMW garage in my area so I am gonna pay $140 labor to have them find the leak once the warranty runs out. Other than that everything on the car works as it is supposed to. Sorry, you are going through this but a lot of us have the same problem. Be sure to mix the antifreeze correctly it is very important. Read this.
https://www.newtis.info/tisv2/a/en/g...ooling/1HZe3We

[Desmond79]

Originally Posted by b74heavy

I have a 2019 540i. I have had the same problem. At 7200 miles I got a coolant low warning light. I carefully drove to the dealer. He filled up the High-pressure system and pressurized the system for 30 min and said that there were no leaks. Then told me that sometimes the factory doesn't fill the system all the way. I didn't believe them so I bought a quart of BMW spec antifreeze and went to the grocery store and bought a gallon of distilled water. I was ready for it to leak down if it happened again. So at about 14000 miles, I checked the antifreeze and it was down again. I mixed a batch of 50% antifreeze and 50% distilled water. So I followed this process again about every 5000 to 6000 miles. I now have 39000 miles on my 540i and the boil-off or leak has not gotten any worse. So my Service Advisor said not to refill it and as soon as the warning comes on again drive straight to the dealer to trouble shoot it so they can fix it. I am able to mix and install the antifreeze so I guess I will quit fighting with them. I have had them leak check it 2 times and they found no leaks. There is a very good BMW garage in my area so I am gonna pay $140 labor to have them find the leak once the warranty runs out. Other than that everything on the car works as it is supposed to. Sorry, you are going through this but a lot of us have the same problem. Be sure to mix the antifreeze correctly it is very important. Read this.
https://www.newtis.info/tisv2/a/en/g...ooling/1HZe3We

Have you checked for evidence of a leak? On driveway? Garage? Opened hood and felt the metal wet below the expansion tank?

When I returned home with a Cert PreOwned 540i M, I looked at my driveway and saw the drip, drip, drip. Opened hood, saw liquid below coolant and expansion tank.

Took it back next morning, showed SA the leak and we both got on our knees and he saw it. Opened trunk, he saw some small squirting from expansion tank. Covered under warranty.

In my 2000, 2009 3 series, and 2014 535, they all needed filling occasionally. Even the owner's manual says you need to top it off occasionally.

As to yours going so low, I would never have it go too low - the biggest threat to an engine is heat and friction (my undertanding). Keep it at the minimum at least. Take a pic before you fill it and take it to SA.

I took a video of the drip, drip and expansion tank area and texted it to SA before I came in.

[b74heavy]

Originally Posted by Desmond79

Have you checked for evidence of a leak? On driveway? Garage? Opened hood and felt the metal wet below the expansion tank?

When I returned home with a Cert PreOwned 540i M, I looked at my driveway and saw the drip, drip, drip. Opened hood, saw liquid below coolant and expansion tank.

Took it back next morning, showed SA the leak and we both got on our knees and he saw it. Opened trunk, he saw some small squirting from expansion tank. Covered under warranty.

In my 2000, 2009 3 series, and 2014 535, they all needed filling occasionally. Even the owner's manual says you need to top it off occasionally.

As to yours going so low, I would never have it go too low - the biggest threat to an engine is heat and friction (my undertanding). Keep it at the minimum at least. Take a pic before you fill it and take it to SA.

I took a video of the drip, drip and expansion tank area and texted it to SA before I came in.

Good Idea I will give it a try. I was not wild about letting it go till I got a warning. I have a checklist I do every month. I check the tire pressure, oil level, and antifreeze coolant level. So I have been keeping track. I have lost just a little over 2 liters of coolant in 32000 miles. I want to take a trip with this car so I guess I will take some premixed antifreeze with me. I have looked very carefully at all the connections I can see around the radiator under the expansion tank and have found nothing. No smell or visible leak on the ground in the garage. One thing though the cap for the expansion tank has a white residue under it like it might not be sealing very well. The first time I took the cap off it was almost impossible to unscrew. The cap is now very easy to unscrew. They have pressure checked the system twice and found no leaks. So I asked what about the cap. I wonder if when it is pressurized the fluid loss is just evaporation from a leaking cap. It almost has to be if they did the pressure check correctly. After I drive it around today I will pop the hood and really look for a leak. That is one thing I haven't done. Thanks for the info.

[Desmond79]

Originally Posted by b74heavy

Good Idea I will give it a try. I was not wild about letting it go till I got a warning. I have a checklist I do every month. I check the tire pressure, oil level, and antifreeze coolant level. So I have been keeping track. I have lost just a little over 2 liters of coolant in 32000 miles. I want to take a trip with this car so I guess I will take some premixed antifreeze with me. I have looked very carefully at all the connections I can see around the radiator under the expansion tank and have found nothing. No smell or visible leak on the ground in the garage. One thing though the cap for the expansion tank has a white residue under it like it might not be sealing very well. The first time I took the cap off it was almost impossible to unscrew. The cap is now very easy to unscrew. They have pressure checked the system twice and found no leaks. So I asked what about the cap. I wonder if when it is pressurized the fluid loss is just evaporation from a leaking cap. It almost has to be if they did the pressure check correctly. After I drive it around today I will pop the hood and really look for a leak. That is one thing I haven't done. Thanks for the info.

Good idea to check the cap -- they should give you one. I always keep coolant and a quart of oil in the trunk for long trips even if I did not suspect a leak. Good luck with it!

[Frozen Fractals]

My 2018 540i xDrive also exhibits loss of coolant. It is a very minuscule with about the amount between the minimum and maximum fill line in the coolant expansion tank every 10k miles or so. I purchased it as CPO with about 40k miles and it now has about 60k miles on the odometer.

The other day I was tinting my fog lights which required removing the bumper and wheel liner. In doing so, I discovered that the B58 has a displaced/remote radiator on the bottom front right of the car behind where the passenger side (LHD car) fog light would be. Upon investigation on the parts catalog, it looks like this remote radiator connects directly to the main high temperature radiator via two relatively long coolant hoses.

I spotted telltale signs of a slow leak due to the splash guard being slightly discolored from dried up coolant. I suspect one of the fittings (lower one) is slowly seeping coolant out when the system is up to operating temperature/pressurized. I'm not sure if I should bring this up to the dealer, but for now I think I will just keep an eye on it. The rate of coolant loss hasn't noticeably increased in the past 20k miles of my ownership.

To anyone else exhibiting slow coolant loss, it might be worth checking out that area to see if there are signs of any leaks. It's quite easy to access...just raise/jack up the front right corner of the car and remove the front right wheel liner. From there, you should be able to see the remote radiator and the splash guard below it to determine if there are any leaks or not.