[beamersauce]

My car has nearly 48k miles on it and I have had the coolant go below the MIN level twice. The first time it happened was close to 35k. I got the low coolant warning and went to the nearest BWM dealership where they refilled both reservoirs. There was actually even a designated line for fluid top off at this dealership in southern california.

I had the car inspected at another dealership when I got back home and they ran a pressure test that showed no issues. I was informed to keep an eye on the level and to take it back in if it happened again.

Checked the coolant earlier this week and noticed it was below the MIN line on the main tank only. The turbo coolant level was still fine, and I did not get a low warning this time around. Took it in this morning and ran a pressure test again. Results came back good and they topped it off. They said that there was probably a wrong mix of coolant/water which caused evaporation. When I had it filled at the first dealership at 35k, they only added coolant without any water. I don't know if this affected anything or made a difference.

I haven't seen any leaks in my garage and also asked the dealer to check the radiator for any damage like others had reported. I have quite a few miles on my car so I wanted to just write this up so that we can all keep an eye out to see if this is going to be an ongoing thing with the b58.

[B58togo]

Got my first warning at 19.5k and topped it off. Currently close to 38k, so I plan to check it soon.

[keylime503]

I've had to top off my B58's main coolant tank (not the smaller intercooler coolant tank) several times. I had it checked at the dealer after the first incident for a faulty cap but they said they didn't find anything wrong with it.

[XutvJet]

Perhaps B58 owners should start checking their intake manifolds for tiny coolant leaks like some M3/M4 owners are experiencing?

https://f80.bimmerpost.com/forums/sh....php?t=1570544

[TajoMan]

My tank was almost empty after 7~8k miles. (no warning)
Topped off and level is not going down a lot but still losing some.

The coolant level went from Max to Min in about 10k miles which is not much.
Topped off again (3~4 oz).
It could be the leaky cap.

I am checking the coolant level every few month.

[TajoMan]

Originally Posted by XutvJet

Perhaps B58 owners should start checking their intake manifolds for tiny coolant leaks like some M3/M4 owners are experiencing?

https://f80.bimmerpost.com/forums/sh....php?t=1570544

For me, it's always the main tank.

The intercooler is cooled by secondary coolant circuit. (which hasn't dropped a bit)

[amw896]

I must be crazy but I'm pretty sure there is nothing ok about a motor ingesting or losing coolant mysteriously. Dealers saying it's fine makes me second guess their knowledge.

[2016M235i]

Originally Posted by amw896

I must be crazy but I'm pretty sure there is nothing ok about a motor ingesting or losing coolant mysteriously. Dealers saying it's fine makes me second guess their knowledge.

I agree. Nothing normal about that degree of coolant loss. The dealers are just being lazy and don't want to get into a potentially expensive repair that isn't easy to diagnose.

[amw896]

Originally Posted by 2016M235i

I agree. Nothing normal about that degree of coolant loss. The dealers are just being lazy and don't want to get into a potentially expensive repair that isn't easy to diagnose.

Agreed!! I stopped going to the stealers altogether, even for free maintenance because I have 0 faith in their ability. A good indy is priceless these days.

[beamersauce]

Originally Posted by 2016M235i

I agree. Nothing normal about that degree of coolant loss. The dealers are just being lazy and don't want to get into a potentially expensive repair that isn't easy to diagnose.

I totally agree as well. I don't know what else to do then to keep a log of this occurrence with the dealers as it continues to happen. It really seems like a very common issue with the B58 since so many people have reported various low coolant levels.

In some ways, I'm glad that I'm not the only one experiencing this. But, I also wish that we would get some clarity on why this is happening in the first place.

[omera60]

I looked at BMW’s internal system, PuMA, for you guys and this is what came up;

PuMA measure
B38, B46, B48, B58, XB1H - Check Control message: Top up coolant
63482185-05

Complaint:
Check Control message (ID 166): Top up coolant
The coolant level in the coolant expansion tank of the high-temperature coolant circuit is below the minimum.
There may also be traces of coolant in the engine compartment or where the vehicle is parked.

Cause
There are various possible causes:

The cooling system was not sufficiently bled initially. While driving the
cooling system bleeds and as a result the coolant level drops in the coolant expansion tank.

The cooling system is leaking (impermissible coolant loss).
Measure
+++
Revision to the previous version of the PuMA measure:
Note:
Bleeder screw: Observe tightening torque of 2.5 Nm.
+++

In the event of a customer complaint, proceed as follows:

Attention:
Only perform the following work on cooled-down components.

1) Check coolant circuit for watertightness:
See repair Instructions 17 00 009.
Check the high-temperature coolant circuit for watertightness using test for loss of pressure.
Test pressure of cooling system (excess pressure): 1.5 bar
test period: 10 minutes

2) Observe pressure:
No pressure drop: Continue with point 4.
Pressure drop present: Continue with point 3.

3) Search for leak.

Check coolant pump.
The coolant pump has a reservoir. During engine operation the
slide ring seal of the coolant pump needs to be lubricated. The coolant required for lubrication is collected in the
reservoir. Slight traces of coolant could be visible on the lid of the reservoir.

Slight traces of coolant on lid of reservoir (see attachment, figure 1):
Clean the lid. Check if coolant leaks again at the lid if excess pressure of 1.5 bar is applied.
- If coolant is leaking: Replace coolant pump.
- No coolant leaking: Do not replace coolant pump. Search for leak and
repair accordingly.

Excessive traces of coolant on lid of reservoir (see attachment, figure 2 and 3):
Replace coolant pump.

After repairing the leak:
Bleed cooling system and check for watertightness:
See repair Instructions 17 00 039.
Note:
Bleeder screw: Observe tightening torque of 2.5 Nm.

4) Release pressure:
Adjust the filling level in the coolant expansion tank of the high-temperature coolant circuit.
In doing so, it is imperative to follow repair instructions 17 00 039.
The filling level in the coolant expansion tank is adjusted either to the maximum mark or 200 ml above it, depending on the model.

Notes on factory filling of high-temperature coolant circuit:
The initial coolant circuit capacity of the high-temperature coolant circuit was already optimised in the vehicle factories.
The introduction dates are:
F20, F21, F22, F23, F30, F31, F32, F33, F34, F35, F36: 01 September 2017
G11, G12: 5 June 2018
G30, G31, G32: 01 February 2019
G38: as of series launch
Invoicing:
Processing and reimbursement must be conducted according to current warranty conditions.

In case of defective cooling system bleeding, use the following defect code.
Recommended defect code for GWK cases: 17 11 00 72 00

Use the following defect code for a leaking coolant pump.
Recommended defect code for GWK cases: 11 51 07 48 00
For other leakages.
Obtain the corresponding defect code from the "Commercial Service Data (KSD)".
Validity information
Model series:[F30, F21, F32, G31, F31, F20, G30, F23, G11, F34, F33, G32, F22, F36, F35, G12, G38]
Engine range:[B58M, B48M, B46O, B48O, XB1H, B38M]
Body style:[ALL]
Fault codes:[]
Production period:-

[TajoMan]

Originally Posted by amw896

Agreed!! I stopped going to the stealers altogether, even for free maintenance because I have 0 faith in their ability. A good indy is priceless these days.

They do have BMW's internal guideline. That's a big advantage for this type of issue.
Manufacturer has all the warranty data and dealers are instructed by manufacturer.

For B58 coolant 'leak' issue, I think initial big drop in coolant level was improper fill from the factory.
(mine emptied the tank in 8k miles while my wife's is still fine at 4k miles)

However, mine keeps 'leaking' small amount.
It can be coolant tank cap leak or leaking somewhere internally. (no visible coolant drops on the garage floor)

There are only so many it can leak internally.
Engine block/head (unlikely with closed deck), oil cooler (oil level will go up), trans cooler, turbo....that's about it

I hope it's not the turbo internal leak.

[beamersauce]

Originally Posted by TajoMan

They do have BMW's internal guideline. That's a big advantage for this type of issue.
Manufacturer has all the warranty data and dealers are instructed by manufacturer.

For B58 coolant 'leak' issue, I think initial big drop in coolant level was improper fill from the factory.
(mine emptied the tank in 8k miles while my wife's is still fine at 4k miles)

I hope it's not the turbo internal leak.

I may have had low coolant when purchased as well, but when it dropped again recently I know that this will probably be a reoccurring issue.

I had read another post about replacing the turbo after bmw had inspected his car. Didn't hear anymore details about it though.

[beamersauce]

Originally Posted by omera60

I looked at BMW’s internal system, PuMA, for you guys and this is what came up;

PuMA measure
B38, B46, B48, B58, XB1H - Check Control message: Top up coolant
63482185-05

Complaint:
Check Control message (ID 166): Top up coolant
The coolant level in the coolant expansion tank of the high-temperature coolant circuit is below the minimum.
There may also be traces of coolant in the engine compartment or where the vehicle is parked.

Cause
There are various possible causes:

The cooling system was not sufficiently bled initially. While driving the
cooling system bleeds and as a result the coolant level drops in the coolant expansion tank.

The cooling system is leaking (impermissible coolant loss).
Measure
+++
Revision to the previous version of the PuMA measure:
Note:
Bleeder screw: Observe tightening torque of 2.5 Nm.
+++

In the event of a customer complaint, proceed as follows:

Attention:
Only perform the following work on cooled-down components.

1) Check coolant circuit for watertightness:
See repair Instructions 17 00 009.
Check the high-temperature coolant circuit for watertightness using test for loss of pressure.
Test pressure of cooling system (excess pressure): 1.5 bar
test period: 10 minutes

2) Observe pressure:
No pressure drop: Continue with point 4.
Pressure drop present: Continue with point 3.

3) Search for leak.

Check coolant pump.
The coolant pump has a reservoir. During engine operation the
slide ring seal of the coolant pump needs to be lubricated. The coolant required for lubrication is collected in the
reservoir. Slight traces of coolant could be visible on the lid of the reservoir.

Slight traces of coolant on lid of reservoir (see attachment, figure 1):
Clean the lid. Check if coolant leaks again at the lid if excess pressure of 1.5 bar is applied.
- If coolant is leaking: Replace coolant pump.
- No coolant leaking: Do not replace coolant pump. Search for leak and
repair accordingly.

Excessive traces of coolant on lid of reservoir (see attachment, figure 2 and 3):
Replace coolant pump.

After repairing the leak:
Bleed cooling system and check for watertightness:
See repair Instructions 17 00 039.
Note:
Bleeder screw: Observe tightening torque of 2.5 Nm.

4) Release pressure:
Adjust the filling level in the coolant expansion tank of the high-temperature coolant circuit.
In doing so, it is imperative to follow repair instructions 17 00 039.
The filling level in the coolant expansion tank is adjusted either to the maximum mark or 200 ml above it, depending on the model.

Notes on factory filling of high-temperature coolant circuit:
The initial coolant circuit capacity of the high-temperature coolant circuit was already optimised in the vehicle factories.
The introduction dates are:
F20, F21, F22, F23, F30, F31, F32, F33, F34, F35, F36: 01 September 2017
G11, G12: 5 June 2018
G30, G31, G32: 01 February 2019
G38: as of series launch
Invoicing:
Processing and reimbursement must be conducted according to current warranty conditions.

In case of defective cooling system bleeding, use the following defect code.
Recommended defect code for GWK cases: 17 11 00 72 00

Use the following defect code for a leaking coolant pump.
Recommended defect code for GWK cases: 11 51 07 48 00
For other leakages.
Obtain the corresponding defect code from the "Commercial Service Data (KSD)".
Validity information
Model series:[F30, F21, F32, G31, F31, F20, G30, F23, G11, F34, F33, G32, F22, F36, F35, G12, G38]
Engine range:[B58M, B48M, B46O, B48O, XB1H, B38M]
Body style:[ALL]
Fault codes:[]
Production period:-

Thanks for posting this. I'll have the dealer look specifically at the coolant pump the next time this happens. I know they ran the pressure twice, so this will be another thing to ask for in the future.

[dradernh]

Originally Posted by beamersauce

I had read another post about replacing the turbo after bmw had inspected his car. Didn't hear anymore details about it though.

Was that on the B58, or the N55?

[AndDown]

I have the B48 engine and have topped it up twice from just below the minimum level, car has 8K miles. Our other car has the N20 engine and it has not dropped at all in 28K miles. Don’t know why BMW went to the all black opaque expansion tank with the B-engines, unlike the N-engines which have a translucent tank which makes it much easier to see without having to remove the filler cap.

[beamersauce]

Originally Posted by dradernh

Was that on the B58, or the N55?

An owner named bayern68 reported a new turbo under warranty with his B58 (2016 production). This actually wasn't the same user I found originally when I said someone got a new turbo, but when I searched again I found his post.

https://f30.bimmerpost.com/forums/showthread.php?t=1324221&page=5

[seansurfn2]

Ill be watching this thread as im about to buy a 240i.. i know the b58 has a different block design and that keeping the engine cool with the closed deck is also different. im sure theres something bmw hasnt admitted yet.. maybe the type of coolant? id check for leaks too.. coolant just burning off that fast seems strange

[beamersauce]

Originally Posted by seansurfn2

Ill be watching this thread as im about to buy a 240i.. i know the b58 has a different block design and that keeping the engine cool with the closed deck is also different. im sure theres something bmw hasnt admitted yet.. maybe the type of coolant? id check for leaks too.. coolant just burning off that fast seems strange

Please check the coolant level when you take delivery! Would love to debunk the claims about the cars being under filled from the factory. I really don't think that's happening.

[TajoMan]

Originally Posted by beamersauce

Please check the coolant level when you take delivery! Would love to debunk the claims about the cars being under filled from the factory. I really don't think that's happening.

You will not know by just looking in the tank at the delivery.

Air pocket in the cooling system will drop the coolant level after driven for a while.

[morphomeman]

I had a low coolant incident once with my 235 a couple of years ago. My daughter was driving and she had the sense to address the problem. Nothing since. The car now has almost 40000 miles on it.
Knock wood!!

[beamersauce]

Originally Posted by TajoMan

You will not know by just looking in the tank at the delivery.

Air pocket in the cooling system will drop the coolant level after driven for a while.

I see. That's good to know.

So is there a way to see if these are really underfilled from delivery then? How does someone monitor their levels to make sure it's adequately filled?