Coolant reservoir ...(prob another noob question)

[Josh_F82]

So I'm getting notified my coolant is really low and needs to be topped off. Instead of driving two hours back to the dealer for something as simple as adding coolant, I'm figuring it prob best to get coolant from a BMW and add it myself (saving their laughter as well).

The catch is my intuition is everything on BMWs is different from a regular car lol, so don't touch anything lol. It looks like I see two reservoirs, one smaller one far up by the windshield and one further down. Which one of these two do I fill? #1 on top or #2 at the bottom (...These are the right reservoirs right?). How do I know how much to put in?

[SakhirM4]

That's what the owners manual is for:

[AustinGelbM4]

No 2 is for your engine coolant. No 1 is for your Intercooler coolant.

[Josh_F82]

Originally Posted by AustinGelbM4

No 2 is for your engine coolant. No 1 is for your Intercooler coolant.

Thank you. I'd have to check again to see, but I'm pretty sure it didn't tell me which one of the two were low. How would I know which needs filling? Or is it best to just check the levels of both?

[SakhirM4]

Originally Posted by Josh_F82

Thank you. I'd have to check again to see, but I'm pretty sure it didn't tell me which one of the two were low. How would I know which needs filling? Or is it best to just check the levels of both?

Did you even read the pages from the manual that I posted? Your questions are answered there.

[Josh_F82]

Originally Posted by SakhirM4

Did you even read the pages from the manual that I posted? Your questions are answered there.

Yes.... I did read them.... thank you very much.

I was asking incase there was any additional feedback he was able to provide based off his response. Thanks again.

[Josh_F82]

Originally Posted by Josh_F82

Yes.... I did read them.... thank you very much.

I was asking incase there was any additional feedback he was able to provide based off his response. Thanks again.

It says check both. Some people may know from personal experience that one may typically be more effected than another which is why I asked. A simple starting point.

[SakhirM4]

Originally Posted by Josh_F82

It says check both. Some people may know from personal experience that one may typically be more effected than another which is why I asked. A simple starting point.

You should have your car checked for a leak. I have had my M4 almost 3 years and have never had to add coolant.

[AustinGelbM4]

Originally Posted by Josh_F82

Thank you. I'd have to check again to see, but I'm pretty sure it didn't tell me which one of the two were low. How would I know which needs filling? Or is it best to just check the levels of both?

Check both when car is cold. The coolant system is a closed system. You shouldn't have to add or top up. If you check and you indeed have to add coolant you may have a leak. After adding I would recommend you check the coolant every morning or before first drive of the day. If you have to add even as much as a 1/4 cup again get it checked out. Small coolant leak may not necessarily be an expensive fix but left unchecked COULD cost you $$$$$$$$$. G/L and welcome to the forum

[dzvero]

Also If you dont top off soon you might get overheating message if you have leak. Just buy the coolant from the dealer. Check the level, if its not missing much call them to verify they have it in quarter bottle. Dont go cheap and use regular , not that bmw one is too special but not to mix them.

[Josh_F82]

Originally Posted by AustinGelbM4

Check both when car is cold. The coolant system is a closed system. You shouldn't have to add or top up. If you check and you indeed have to add coolant you may have a leak. After adding I would recommend you check the coolant every morning or before first drive of the day. If you have to add even as much as a 1/4 cup again get it checked out. Small coolant leak may not necessarily be an expensive fix but left unchecked COULD cost you $$$$$$$$$. G/L and welcome to the forum

Thank you. I literally just got it from dealer few days ago, so I do find it little strange that it's that low. Intercooler side was fine, but I'd say I had to add a little less than a liter to the other one. I added it (50/50 mixture) cold and let it run for a bit and didn't see signs of leakage jumping out at me. I'll deff check again tomorrow. Everything's still under warranty, so if any signs of it getting low again, I'll deff take back to get looked at. Thank you for the help.

[TurboM]

Originally Posted by Josh_F82

Thank you. I literally just got it from dealer few days ago, so I do find it little strange that it's that low. Intercooler side was fine, but I'd say I had to add a little less than a liter to the other one. I added it (50/50 mixture) cold and let it run for a bit and didn't see signs of leakage jumping out at me. I'll deff check again tomorrow. Everything's still under warranty, so if any signs of it getting low again, I'll deff take back to get looked at. Thank you for the help.

Why guess and/or spend your own time/money trying to figure it out? Just take it to the dealer and let them figure it out. The car is under warranty, use it!

[STR8-6IX]

you can top it off with distilled water no problem. even for the winter, its best to have a 50/50 mix anyways.. water works better then coolant.

your coolant will read higher when the engine is warm so keep in mind its best to top up when cold.

[AustinGelbM4]

Originally Posted by STR8-6IX

you can top it off with distilled water no problem. even for the winter, its best to have a 50/50 mix anyways.. water works better then coolant.

your coolant will read higher when the engine is warm so keep in mind its best to top up when cold.

Water is thermally more efficient but its not BETTER. There is a reason its a mix. Additives are needed to make water more SUITABLE. Eg. Cold climates need anti-freeze. Even in tropical climates you will still need anti-rust and lubrication etc. Some manufacturer labeled coolant is pre-mixed for you and you just add while some give you instructions on how to mix/ratio. Either way just follow their guidelines.

[STR8-6IX]

Originally Posted by AustinGelbM4

Water is thermally more efficient but its not BETTER. There is a reason its a mix. Additives are needed to make water more SUITABLE. Eg. Cold climates need anti-freeze. Even in tropical climates you will still need anti-rust and lubrication etc. Some manufacturer labeled coolant is pre-mixed for you and you just add while some give you instructions on how to mix/ratio. Either way just follow their guidelines.

hmm.. my car burns coolant fairly quick. I probably have more then half mix now.. I havent worried about it until you brought this up but im gonna need to buy some coolant soon.

does it have to be BMW coolant? anything else I can use, like maybe OEM supplier something like this?

[AustinGelbM4]

Originally Posted by STR8-6IX

hmm.. my car burns coolant fairly quick. I probably have more then half mix now.. I havent worried about it until you brought this up but im gonna need to buy some coolant soon.

does it have to be BMW coolant? anything else I can use, like maybe OEM supplier something like this?

You should not be "burning" through coolant. Its a closed system. In the OPs case a "mistake" could have resulted in the low coolant (Coolant cap not properly tightened after service which results in coolant leaking out etc). Hence why I suggested that if more still needs to be added there may be a leak. You probably have a leak too. Where the mix/ratio is concerned........you don't want to deviate too far from manufacturers recommendations. Water maybe thermally very efficient but too much water (which can happen if you top-up with water only) usually results in components (even major ones like the pump etc) rusting. This can make your issues worse. The BMW coolant I have used in the past required a mix of one to one. One part BMW coolant to one part water. The mix instructions will be on the bottle. Just follow them. If you need to top-up, the proper way with the BMW coolant that I have used in the past would require that I mix one part BMW coolant to one part water THEN add that mix to car. This would keep the ratio correct. But again, if you have to keep topping up you have a problem so get it checked. The fix could range from something simple like a faulty hose clamp to something much more expensive like a bad head gasket. Just to give you an idea, I have not needed to add as much as 1 drop to the M4 in 6 mths and I have added maybe a TOTAL of 1 qt in the 13+ yrs I have been driving the 330Ci.

I would recommend sticking with the BMW coolant or at least coolant free from nitrite.

Hope this helps. G/L

[STR8-6IX]

Originally Posted by AustinGelbM4

You should not be "burning" through coolant. Its a closed system. In the OPs case a "mistake" could have resulted in the low coolant (Coolant cap not properly tightened after service which results in coolant leaking out etc). Hence why I suggested that if more still needs to be added there may be a leak. You probably have a leak too. Where the mix/ratio is concerned........you don't want to deviate too far from manufacturers recommendations. Water maybe thermally very efficient but too much water (which can happen if you top-up with water only) usually results in components (even major ones like the pump etc) rusting. This can make your issues worse. The BMW coolant I have used in the past required a mix of one to one. One part BMW coolant to one part water. The mix instructions will be on the bottle. Just follow them. If you need to top-up, the proper way with the BMW coolant that I have used in the past would require that I mix one part BMW coolant to one part water THEN add that mix to car. This would keep the ratio correct. But again, if you have to keep topping up you have a problem so get it checked. The fix could range from something simple like a faulty hose clamp to something much more expensive like a bad head gasket. Just to give you an idea, I have not needed to add as much as 1 drop to the M4 in 6 mths and I have added maybe a TOTAL of 1 qt in the 13+ yrs I have been driving the 330Ci.

I would recommend sticking with the BMW coolant or at least coolant free from nitrite.

Hope this helps. G/L

I dont understand where the coolant goes, I removed the belly pan to service the transmission fluid some time back and the bottom of the pan was bone dry so I know there are no leaks, but it seems to dissapear quicker when I drive aggressively so I assume that it is being burnt through the engine. my dad has a mazda, my friend an acura and both of them were about 500ML low on coolant and needed to be topped up as well and all of these vehicles are new so I know they are not leaking.

there is no chance that the coolant burns over time? maybe evaporate?

[AustinGelbM4]

Originally Posted by STR8-6IX

I dont understand where the coolant goes, I removed the belly pan to service the transmission fluid some time back and the bottom of the pan was bone dry so I know there are no leaks, but it seems to dissapear quicker when I drive aggressively so I assume that it is being burnt through the engine. my dad has a mazda, my friend an acura and both of them were about 500ML low on coolant and needed to be topped up as well and all of these vehicles are new so I know they are not leaking.

there is no chance that the coolant burns over time? maybe evaporate?

I dont understand either. Under normal conditions unlike oil, coolant never comes into contact with any combustion so you shouldn't be "burning" any. Its a closed system under pressure, there is nowhere for the coolant to evaporate to. I wouldn't be comfortable continually topping up coolant. Keep an eye on it and report back if you eventually find something.

[trynalivepro]

Any updates?

[///F80M3]

I've been topping off the past two days now and every morning the coolant is gone in both reservoirs. I don't see any coolant stains so I'm guessing the intercooler is leaking internally. Going to have it checked out this week.

[mwh2009]

Originally Posted by ///F80M3

I've been topping off the past two days now and every morning the coolant is gone in both reservoirs. I don't see any coolant stains so I'm guessing the intercooler is leaking internally. Going to have it checked out this week.

That sound more significant than the issue I had with the 340i before I got my F80, but there was a discussion about low coolant errors in the forum for 340s.

One of the thoughts there was that there were a bad batch of coolant caps out there that didn't seal properly and helped explain the losses...

[MarcoM3]

Originally Posted by SakhirM4

Did you even read the pages from the manual that I posted? Your questions are answered there.

Why does his question bother you so much? If the question is too simple or obvious for you, just ignore it. Some folks are genuinely new to the marquee or don't know everything there is to know about BMW's. To each his own, mate. Don't you think?

Josh, not sure if you ever got it fixed but the intercooler reservoir tends to snap at the seam and slowly leak right onto the mud pan below; and then the engine heat evaporates it. This is why sometimes you don't see any leaks on the floor.
Had that happen to me on my M4 and ended up getting it replaced right after it went out of warranty. Cost me about $900 at the dealer.

Hope this helps!

Best,

Marco