[rangerbob]

check coolant light came on at 20k miles (340i); added about a quart and it was full. No problems since - now at 22K.

[dsc888]

I took my 340ix to the dealer and mentioned that this is still happening and the shop foreman said that it is a common issue and there is no fix. They topped of the larger intercooler reservoir and pressure tested the system again and there were indeed no leaks again.

Interestingly enough, I check the caps this morning and they were not super tight like they were before I went to service. They didn't replace them but maybe cleaned off the threads which had some with powder on them indicating that the system was venting and losing coolant through that point.

[highpurr]

So I have a 2016 340i xdrive 40500 miles. I had this issue happen about 2 months ago when I took it in they said my water pump was leaking. I squeaked by on the last week of my warranty getting that fixed and I thought that was the end of it. 2 days ago I got the low coolant light warning. When I checked it, it was way low. I did notice a little bit of white residue on the tank. I also was in the mountains over the weekend where it could have been hot from driving down the mountain in a lower gear. I was planning to go get a pressure test but is it possible that there could be a head gasket issue or something more serious? I do not smell coolant in the exhaust. I obviously doubt its the water pump since that is brand new. Could I have lost that much from a cap?

PS. this is my first post so if there was some issue I apologize. Thanks!

[kern417]

Checked mine again over the weekend and it was almost dry. This is the 2nd time and I'm now at 12k miles. I replaced the coolant cap to see if that fixes the issue. The threads were covered with coolant like usual, making the cap extremely difficult to remove.

[dmaxdmax]

Originally Posted by highpurr

So I have a 2016 340i xdrive 40500 miles. I had this issue happen about 2 months ago when I took it in they said my water pump was leaking. I squeaked by on the last week of my warranty getting that fixed and I thought that was the end of it. 2 days ago I got the low coolant light warning. When I checked it, it was way low. I did notice a little bit of white residue on the tank. I also was in the mountains over the weekend where it could have been hot from driving down the mountain in a lower gear. I was planning to go get a pressure test but is it possible that there could be a head gasket issue or something more serious? I do not smell coolant in the exhaust. I obviously doubt its the water pump since that is brand new. Could I have lost that much from a cap?

PS. this is my first post so if there was some issue I apologize. Thanks!

How much did you need to add?

You might not have lost that all from the cap...but it might be from having done your water pump 2 months ago and driving down a mountain. I'm thinking that after any coolant system opening, there's always some top up required afterward. Not sure if they told you to check it or not, but you lose volume over time as air leaves the coolant--some will be in it. Also, bleeding doesn't quite circulate the system as driving does. Your high revs coming down the mtn. may have dislodged air bubbles that were hiding inside the system somewhere.

I wouldn't worry too much; I'd worry enough to check the level regularly until I know it's stable. Unfortunately this thing is well sealed up underneath, so I won't suggest lifting it up and removing the underskirt and looking just yet, but if you keep needing to add coolant (when the car is cold on level ground), then get it back to the dealer, or find the leak yourself. The hoses on this, though plentiful, seem easy enough to replace (if you can get to them). If you're leaking coolant, you'll be able to see it. If not, they do make a UV dye that'd help...but I hope you don't need anything more than the coolant you added.

[Gnslngr]

I bought a 2016 340i last October and the low coolant warning has come on twice. It had just over 30k when i took delivery and probably has less than 35k on it now. I don't see any leaks and don't smell any coolant but it must be going somewhere. I only know of the one coolant reservoir and topped it off with BMW coolant, only to have the low coolant indicator come on again 3-4 weeks later. I find it hard to believe this much coolant(approx. a quart) would have been consumed under normal driving conditions or leaking past the cap because there is no evidence of coolant anywhere near it. Getting two warnings in only a few thousand miles has me seriously worried and even if the turbo is the weak link then how likely is a replacement to last before the same problem recurs. Ironically when I checked Consumer Reports 2016 seemed like a good model year but with so many people having this coolant issue it's hard to believe how it didn't show up in their reporting. I love the car but am not interested in owning a car with a propensity to burn coolant or with faulty turbos so unless the dealer can promise a convincing cure when I take it in on Monday I think I am going to ask them to buy it and get into a different vehicle.

[kern417]

Originally Posted by Gnslngr

I bought a 2016 340i last October and the low coolant warning has come on twice. It had just over 30k when i took delivery and probably has less than 35k on it now. I don't see any leaks and don't smell any coolant but it must be going somewhere. I only know of the one coolant reservoir and topped it off with BMW coolant, only to have the low coolant indicator come on again 3-4 weeks later. I find it hard to believe this much coolant(approx. a quart) would have been consumed under normal driving conditions or leaking past the cap because there is no evidence of coolant anywhere near it. Getting two warnings in only a few thousand miles has me seriously worried and even if the turbo is the weak link then how likely is a replacement to last before the same problem recurs. Ironically when I checked Consumer Reports 2016 seemed like a good model year but with so many people having this coolant issue it's hard to believe how it didn't show up in their reporting. I love the car but am not interested in owning a car with a propensity to burn coolant or with faulty turbos so unless the dealer can promise a convincing cure when I take it in on Monday I think I am going to ask them to buy it and get into a different vehicle.

There are 2 tanks, but only the larger one seems to have a level sensor. Which tank did you top off? And how does the other one look?

[cfm56d7b]

Originally Posted by paul e

Does ANYONE know where I can find this TSB number before I bring it back in?

Refreshing this thread. Does anyone have the TSB or any reference number for the coolant leaking through B58 turbo (bearing)?

[cfm56d7b]

Originally Posted by cfm56d7b

Refreshing this thread. Does anyone have the TSB or any reference number for the coolant leaking through B58 turbo (bearing)?

Folks - does any have a copy of the repair order or TSB number?

[StannisBaratheon]

Originally Posted by StannisBaratheon

2016 340i xDrive - 44k miles

My coolant light hasn't come on but looking under the hood yesterday I saw dried coolant residue that must have sprayed out of the cap. It's been hot in the northeast so I'm wondering if moderate/hard driving plus the outside temperature is too much for the cooling system, causing it to burp out of the cap? I cleaned up the area around the cap and I'm going to keep an eye on it. A friend of mine said his mini did the same thing when it got very hot out.

I ended up taking my car in at 49k miles for waste gate ticking on cold start (which they claimed was normal....) and they topped up the coolant since it was low. Closing in on 53k miles today and the coolant is low again so I'm taking it to the dealer tomorrow. Hopefully they'll do a pressure test to check for any leaks. Intercooler reservoir was (and always has been) at the correct level.

[Aldor27]

I have a shadow code for coolant loss

[POMFKIMOCHI]

Still no updates on the turbo replacement?

[Siege29]

Guys when your coolant level goes down you just top off with distilled water with no coolant mixture? I have the same problem with my B48 they found a crack on the hose that connects its from the expansion tank to the cylinder head. "They fix it" but it seems like I'm topping off again.

[kern417]

Originally Posted by Siege29

Guys when your coolant level goes down you just top off with distilled water with no coolant mixture? I have the same problem with my B48 they found a crack on the hose that connects its from the expansion tank to the cylinder head. "They fix it" but it seems like I'm topping off again.

topping off with water once or twice is no big deal but you should be adding coolant to keep the mix somewhat even.

[StannisBaratheon]

Originally Posted by StannisBaratheon

I ended up taking my car in at 49k miles for waste gate ticking on cold start (which they claimed was normal....) and they topped up the coolant since it was low. Closing in on 53k miles today and the coolant is low again so I'm taking it to the dealer tomorrow. Hopefully they'll do a pressure test to check for any leaks. Intercooler reservoir was (and always has been) at the correct level.

I posted this on the B58 thread but I'll post here too:

The coolant leak on the water pump was from the shaft behind the pulley. I was expecting the gasket between the pump and the block. I brought up the wastegate noise again and after further inspection it was now considered excessive so they replaced that along with the water pump under warranty. We'll see how long the new pump holds up, but at least it's an easy DIY repair.

New turbo part number: 11-65-9-423-787
New water pump part number: 11-51-8-632-585
Water pump gasket part number: 11-51-8-632-587

[jbb2388]

What are you guys using for coolant to top off? Anything other than genuine BMW?

[UrbanCarCulture]

Originally Posted by StannisBaratheon

I posted this on the B58 thread but I'll post here too:

The coolant leak on the water pump was from the shaft behind the pulley. I was expecting the gasket between the pump and the block. I brought up the wastegate noise again and after further inspection it was now considered excessive so they replaced that along with the water pump under warranty. We'll see how long the new pump holds up, but at least it's an easy DIY repair.

New turbo part number: 11-65-9-423-787
New water pump part number: 11-51-8-632-585
Water pump gasket part number: 11-51-8-632-587

So its not an actual water pump failure? I might be expericing coolant lose on my 2016 340i. Couple of friends of mines saw coolant dripping from around the water pump and we all assumed the water pump was slowing failing.

[StannisBaratheon]

Originally Posted by UrbanCarCulture

So its not an actual water pump failure? I might be expericing coolant lose on my 2016 340i. Couple of friends of mines saw coolant dripping from around the water pump and we all assumed the water pump was slowing failing.

It is a water pump failure. The pump still works but the shaft is out of spec (either from wear/tear or a manufacturing defect) which caused it to leak. The impeller was still turning (driven by the accessory belt) but without being able actually examine the pump they removed, my theory is that the pump shaft might have too much force placed on it causing the shaft to wear out or causing the hole in the thermostat housing to become enlarged.

[obzen]

Same a few dried saltine deposits on various plastics under the bonnet. Suspect coolant will have to bring that to attention to the stealer ship next time..


Coolant loss for the b58 is known issue, keep an eye on it

[UrbanCarCulture]

Originally Posted by StannisBaratheon

It is a water pump failure. The pump still works but the shaft is out of spec (either from wear/tear or a manufacturing defect) which caused it to leak. The impeller was still turning (driven by the accessory belt) but without being able actually examine the pump they removed, my theory is that the pump shaft might have too much force placed on it causing the shaft to wear out or causing the hole in the thermostat housing to become enlarged.

I doubt BMW would change the water pump without having any warranty since its their manufacture defect?

Originally Posted by obzen

Same a few dried saltine deposits on various plastics under the bonnet. Suspect coolant will have to bring that to attention to the stealer ship next time..


Coolant loss for the b58 is known issue, keep an eye on it

Im also experiencing that white saltine. Im assuming my coolant lose is not just from this issue around the cap but the actual water pump itself?

Also, should I change the cap as well? I heard that's something that is recommended.

[BWbimmer]

Push the dealers, it's certainly not normal. I am at 55000 miles and never had to top up.

[StannisBaratheon]

Originally Posted by UrbanCarCulture

I doubt BMW would change the water pump without having any warranty since its their manufacture defect?



Im also experiencing that white saltine. Im assuming my coolant lose is not just from this issue around the cap but the actual water pump itself?

Also, should I change the cap as well? I heard that's something that is recommended.

Push the dealer and see what you can get. A lot of us have speculated that dealers are being extra generous with warranty replacements since business is slow (and they are reimbursed by BMW for their expense).