Question For Those Of You With S55 Engine Building Experience: Full Coolant Drain?

jmciver · 11-24-2018, 10:21 AM

I am hoping that those of you with experience tearing down/rebuilding the S55 can shed some light on this (or those who have maybe done some extensive work on the cooling system). I am trying to come up with a plan to do a coolant drain/fill for my F80. However, I have yet to find any info on the net, DIY or otherwise, on how to do a full drain/fill for the S55. The ISTA procedure can be found here: https://www.newtis.info/tisv2/a/en/f...eck/1VnXAXagL8

However, this procedure merely tells you to disconnect the lower radiator hose on the passenger side. However, as you will notice from the digram below, the lower radiator hose is nowhere near the bottom of the system:

Several modern coolant drain procedures have you drain the coolant from the radiator. However, the radiator typically holds 25-50% of the coolant in the entire system, with the majority of the coolant remaining in the engine block. Older BMW engine coolant drain procedures have you additionally open an engine block drain plug to completely drain all of the coolant. However, I could not find any block drain plug for the S55 (or any modern BMW engine in FXX vehicles for that matter).

In case you were wondering, the S55 engine coolant system takes a whopping 13.9 liters. Looking at the diagram above, I suspect that draining coolant from the radiator as indicated by the ISTA procedure will only get out a small portion of the coolant from the system. So the million dollar question for me is, have those of you with more experience working in and around this engine figured a way to drain all of the coolant (or at least most of it)? Is there an engine block drain "hidden" on the block?

Without an engine block drain, it seems that disconnecting the hose at the bottom of the water pump on the engine and the lower radiator hose at the auxiliary radiator (both apparent low points in the system) may help to get most of the coolant out. Any other thoughts? It can't be that hard to get a full drain on this engine....?

climax_e92 · 12-05-2018, 12:11 AM

I would like to know as well. I've been wanting to do this since i use to change my coolant every 2 years until i got the m4. Coming up on 3 years now..

jmciver · 12-05-2018, 08:58 AM

Unfortunately, I am beginning to think that this platform is still too "new" so the hardcore DIY'ers have not really ripped into this engine like on some of the older EXX platforms. Also, those who would have this type of technical knowledge, like race shops that tear down these cars on a more regular basis, either don't frequent these parts of the forums or are not willing to share the knowledge yet. Time will tell I guess. My experience has been that typically knowledge like this resides in the track forum, but I posted a similar question there with no joy so I figured I would give this forum a shot.

Who knows, I might just take the plunge myself and contribute to some of the more advanced DIYs for this platform that go above and beyond the ISTA procedures. I am speculating that if there is in fact no drain plug on the block, another alternative to get out most of the coolant may be to use the auxiliary electric pumps to help pump the water out of the system. There are two of them - one for the turbos and one for the heater core

.....

I already have a vacuum fill tool (which was not that expensive), which the ISTA procedures requires and I think is an absolute must to get all the air out of the system due to the "nooks & crannies" that this system has compared to older cars. I just wish there were a documented way to get all of the coolant out of the system without needing to completely tear apart the engine

.

climax_e92 · 12-09-2018, 01:41 AM

Man please let me know if you make a diy or however you decide to do it. If anything i may just take it to the dealer to get done. My gf actually just bought an expansion tank today because we found her coolant reservior to be leaking ! $114 with her bmw employee discount.. she has a 2015 with 51k miles.

IK6SPEED · 12-09-2018, 03:18 AM

Quote:

Originally Posted by climax_e92

Man please let me know if you make a diy or however you decide to do it. If anything i may just take it to the dealer to get done. My gf actually just bought an expansion tank today because we found her coolant reservior to be leaking ! $114 with her bmw employee discount.. she has a 2015 with 51k miles.

What car model?

Fast4d · 12-09-2018, 09:10 AM

there are a number of kits out there that utilize vacuum or pressure to help evacuate or fill coolant. you'll need a compressed air source. a air tight fitting with nipple can be made to fit in a coolant hose, cap,etc and introduce a few psi to clear the system of coolant.

I'm more OCD about oil than coolant.

just like automatic trans I don't bother doing a system flush. I just change out what's in the pan over several changes.

jmciver · 12-09-2018, 06:12 PM

I already have the vacuum fill unit. From what I can gather though, the Venturi effect of the vacuum fill system is probably not enough to evacuate much of the coolant.

I am coming up with a potential plan that involves disconnecting the lower radiator hoses at the primary and aux radiators. Then possibly using the electric water pump of the heating system to try to pump out as much water as I can. Then possibly using some low pressure air to get some more out.

Still bothers me that there is no formal BMW procedure to drain the system other than just disconnecting the lower radiator hose. I don't want to flush it, all I really want to do is drain most of the 13.9 liters of coolant that is in there

....

climax_e92 · 12-09-2018, 08:51 PM

Quote:

Originally Posted by IK6SPEED

What car model?

She has a 15 f80.

domino_z · 12-09-2018, 10:06 PM

in browsing the instructions for replacing the front mount heat exchanger, i recall dinan mentioning that exact same spot to flush coolant from

http://files.dinancars.com/webresour...b3d54717be.pdf

slightly ot, but i don't have all the equipment to do a full refill and pressure, i'm hoping i can just top up on top mount reservoir what i lose removing the front mount and then use the oe fuel pump to push out excess air from system

climax_e92 · 12-18-2018, 12:23 AM

So i finally got the coolant flush done on my 16 m4. My buddy is a shop foreman at an audi dealership and he used to machine to suck a lot of the coolant out, and used the machine to push it back in. Also did the intercooler reservior.

jmciver · 12-18-2018, 09:25 AM

Quote:

Originally Posted by climax_e92

So i finally got the coolant flush done on my 16 m4. My buddy is a shop foreman at an audi dealership and he used to machine to suck a lot of the coolant out, and used the machine to push it back in. Also did the intercooler reservior.

So how much did it cost you? Was it at a BMW dealership or Audi dealership based on what you posted? Even if the BMW dealership uses a machine to flush the system (I had it done once on my 2017 Ford SUV) I am surprised I can not find a procedure for it in ISTA using a BMW "special tool".....

climax_e92 · 12-18-2018, 11:34 PM

Quote:

Originally Posted by jmciver

So how much did it cost you? Was it at a BMW dealership or Audi dealership based on what you posted? Even if the BMW dealership uses a machine to flush the system (I had it done once on my 2017 Ford SUV) I am surprised I can not find a procedure for it in ISTA using a BMW "special tool".....

Yeah had it done at an audi dealer. Machine creates vacuum and sucks the coolant out of the reservoir and pushes the new coolant back in. By using the vacuum machine it eliminates air bubbles so no need for bleeding the system. Was pretty cool watching it. Have a video but cant post. If you message me on IG i can send vid. @m4_teh
Oh and no charge. Just tipped my buddy a $20

jmciver · 12-19-2018, 07:29 PM

Quote:

Originally Posted by climax_e92

Quote:

Originally Posted by jmciver

So how much did it cost you? Was it at a BMW dealership or Audi dealership based on what you posted? Even if the BMW dealership uses a machine to flush the system (I had it done once on my 2017 Ford SUV) I am surprised I can not find a procedure for it in ISTA using a BMW "special tool".....

Yeah had it done at an audi dealer. Machine creates vacuum and sucks the coolant out of the reservoir and pushes the new coolant back in. By using the vacuum machine it eliminates air bubbles so no need for bleeding the system. Was pretty cool watching it. Have a video but cant post. If you message me on IG i can send vid. @m4_teh
Oh and no charge. Just tipped my buddy a $20

I wonder how much coolant the machine was able to get out just using vacuum - there is 13.9 liters in the system. You wouldn't happen to know about how much the machine took out?

I recently purchased the vacuum purge tool by Schwaben to do the coolant on my wife's X3 and my M3. It uses shop air (90 psi) to draw a vacuum on the system via the expansion tank using a Venturi. But the manual specifically says it is only used to vacuum fill the system, not remove old coolant. Even though in theory the vacuum should be strong enough to remove at least some of the coolant from the system. If I could use the vacuum tool to get all or most of the coolant out without having to open up anything, that would be great 😎!!

My local BMW dealer quoted me $170 to get a drain/fill done. Cheaper than I expected, but I am assuming they are using a similar type machine that your buddy used.

climax_e92 · 12-22-2018, 04:10 PM

Hey yeah it was about 3 gallons. Not sure what bmw's procedure would be. I read that they put it on a lift and disconnect hose by the radiator to drain the coolant. My buddy was trying to look for a place to disconnect so he can fully drain everything. Couldn't find a spot so he just used the machine. Took about 30 mins.

jmciver · 12-22-2018, 04:47 PM

Quote:

Originally Posted by climax_e92

Hey yeah it was about 3 gallons. Not sure what bmw's procedure would be. I read that they put it on a lift and disconnect hose by the radiator to drain the coolant. My buddy was trying to look for a place to disconnect so he can fully drain everything. Couldn't find a spot so he just used the machine. Took about 30 mins.

That is actually pretty good. 13.9l = 3.7 gallons so the vacuum method from the expansion tank was able to "suck" most of the coolant out - which is not the case on all cars. I may give my vacuum tool a shot now to see how much I can get out, using shop air from my compressor as my vacuum source with the tool. And as far as the video goes, can you post it up on YouTube (and then post it here)?

climax_e92 · 12-28-2018, 08:32 PM

Quote:

Originally Posted by jmciver

That is actually pretty good. 13.9l = 3.7 gallons so the vacuum method from the expansion tank was able to "suck" most of the coolant out - which is not the case on all cars. I may give my vacuum tool a shot now to see how much I can get out, using shop air from my compressor as my vacuum source with the tool. And as far as the video goes, can you post it up on YouTube (and then post it here)?

Yeah man if you have facebook just add me and shoot me a PM. I'll send it to you that way. https://www.facebook.com/teh.SW20

11-24-2018, 10:21 AM	#1
jmciver ///M SubDriver 1836 Rep 2,783 Posts Drives: 2017 M3, 2020 X7 40i Join Date: Jul 2016 Location: DMV iTrader: (0) Garage List 2017 BMW M3 [10.00] 2020 BMW X7 [0.00] 2019 BMW X3 [0.00] 2009 BMW 128i [0.00]	Question For Those Of You With S55 Engine Building Experience: Full Coolant Drain? I am hoping that those of you with experience tearing down/rebuilding the S55 can shed some light on this (or those who have maybe done some extensive work on the cooling system). I am trying to come up with a plan to do a coolant drain/fill for my F80. However, I have yet to find any info on the net, DIY or otherwise, on how to do a full drain/fill for the S55. The ISTA procedure can be found here: https://www.newtis.info/tisv2/a/en/f...eck/1VnXAXagL8 However, this procedure merely tells you to disconnect the lower radiator hose on the passenger side. However, as you will notice from the digram below, the lower radiator hose is nowhere near the bottom of the system: Several modern coolant drain procedures have you drain the coolant from the radiator. However, the radiator typically holds 25-50% of the coolant in the entire system, with the majority of the coolant remaining in the engine block. Older BMW engine coolant drain procedures have you additionally open an engine block drain plug to completely drain all of the coolant. However, I could not find any block drain plug for the S55 (or any modern BMW engine in FXX vehicles for that matter). In case you were wondering, the S55 engine coolant system takes a whopping 13.9 liters. Looking at the diagram above, I suspect that draining coolant from the radiator as indicated by the ISTA procedure will only get out a small portion of the coolant from the system. So the million dollar question for me is, have those of you with more experience working in and around this engine figured a way to drain all of the coolant (or at least most of it)? Is there an engine block drain "hidden" on the block? Without an engine block drain, it seems that disconnecting the hose at the bottom of the water pump on the engine and the lower radiator hose at the auxiliary radiator (both apparent low points in the system) may help to get most of the coolant out. Any other thoughts? It can't be that hard to get a full drain on this engine....? __________________ ///M3 *COMPETITION 6MT* - 2017 F80 Smoked Topaz Metallic BM3 / MP-HAS / GC Camber Plates / Carbonstructure Interior X7 XDrive 40i ///M-SPORT - 2020 G07 Arctic Grey Metallic X3 XDrive 30i - 2019 G01 Mineral White (wife's) / 128i 6MT - 2009 E82 Jet Black (son's)
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12-05-2018, 12:11 AM	#2
climax_e92 Lieutenant 148 Rep 563 Posts Drives: E92 Join Date: Mar 2014 Location: Los Angeles 661 iTrader: (6)	I would like to know as well. I've been wanting to do this since i use to change my coolant every 2 years until i got the m4. Coming up on 3 years now..
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12-05-2018, 08:58 AM	#3
jmciver ///M SubDriver 1836 Rep 2,783 Posts Drives: 2017 M3, 2020 X7 40i Join Date: Jul 2016 Location: DMV iTrader: (0) Garage List 2017 BMW M3 [10.00] 2020 BMW X7 [0.00] 2019 BMW X3 [0.00] 2009 BMW 128i [0.00]	Unfortunately, I am beginning to think that this platform is still too "new" so the hardcore DIY'ers have not really ripped into this engine like on some of the older EXX platforms. Also, those who would have this type of technical knowledge, like race shops that tear down these cars on a more regular basis, either don't frequent these parts of the forums or are not willing to share the knowledge yet. Time will tell I guess. My experience has been that typically knowledge like this resides in the track forum, but I posted a similar question there with no joy so I figured I would give this forum a shot. Who knows, I might just take the plunge myself and contribute to some of the more advanced DIYs for this platform that go above and beyond the ISTA procedures. I am speculating that if there is in fact no drain plug on the block, another alternative to get out most of the coolant may be to use the auxiliary electric pumps to help pump the water out of the system. There are two of them - one for the turbos and one for the heater core ..... I already have a vacuum fill tool (which was not that expensive), which the ISTA procedures requires and I think is an absolute must to get all the air out of the system due to the "nooks & crannies" that this system has compared to older cars. I just wish there were a documented way to get all of the coolant out of the system without needing to completely tear apart the engine . __________________ ///M3 *COMPETITION 6MT* - 2017 F80 Smoked Topaz Metallic BM3 / MP-HAS / GC Camber Plates / Carbonstructure Interior X7 XDrive 40i ///M-SPORT - 2020 G07 Arctic Grey Metallic X3 XDrive 30i - 2019 G01 Mineral White (wife's) / 128i 6MT - 2009 E82 Jet Black (son's)
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12-09-2018, 01:41 AM	#4
climax_e92 Lieutenant 148 Rep 563 Posts Drives: E92 Join Date: Mar 2014 Location: Los Angeles 661 iTrader: (6)	Man please let me know if you make a diy or however you decide to do it. If anything i may just take it to the dealer to get done. My gf actually just bought an expansion tank today because we found her coolant reservior to be leaking ! $114 with her bmw employee discount.. she has a 2015 with 51k miles.
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12-09-2018, 09:10 AM	#6
Fast4d Captain 267 Rep 885 Posts Drives: 325 Join Date: Jan 2012 Location: So cal iTrader: (0)	there are a number of kits out there that utilize vacuum or pressure to help evacuate or fill coolant. you'll need a compressed air source. a air tight fitting with nipple can be made to fit in a coolant hose, cap,etc and introduce a few psi to clear the system of coolant. I'm more OCD about oil than coolant. just like automatic trans I don't bother doing a system flush. I just change out what's in the pan over several changes. __________________ SAFE-GUARD tire/wheel/windshield/paint protection is a FRAUD! do not waste your money!
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12-09-2018, 06:12 PM	#7
jmciver ///M SubDriver 1836 Rep 2,783 Posts Drives: 2017 M3, 2020 X7 40i Join Date: Jul 2016 Location: DMV iTrader: (0) Garage List 2017 BMW M3 [10.00] 2020 BMW X7 [0.00] 2019 BMW X3 [0.00] 2009 BMW 128i [0.00]	I already have the vacuum fill unit. From what I can gather though, the Venturi effect of the vacuum fill system is probably not enough to evacuate much of the coolant. I am coming up with a potential plan that involves disconnecting the lower radiator hoses at the primary and aux radiators. Then possibly using the electric water pump of the heating system to try to pump out as much water as I can. Then possibly using some low pressure air to get some more out. Still bothers me that there is no formal BMW procedure to drain the system other than just disconnecting the lower radiator hose. I don't want to flush it, all I really want to do is drain most of the 13.9 liters of coolant that is in there .... __________________ ///M3 *COMPETITION 6MT* - 2017 F80 Smoked Topaz Metallic BM3 / MP-HAS / GC Camber Plates / Carbonstructure Interior X7 XDrive 40i ///M-SPORT - 2020 G07 Arctic Grey Metallic X3 XDrive 30i - 2019 G01 Mineral White (wife's) / 128i 6MT - 2009 E82 Jet Black (son's)
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12-09-2018, 10:06 PM	#9
domino_z Lieutenant Colonel 1240 Rep 1,972 Posts Drives: F-Pace SVR Join Date: Apr 2008 Location: Australia iTrader: (0)	in browsing the instructions for replacing the front mount heat exchanger, i recall dinan mentioning that exact same spot to flush coolant from http://files.dinancars.com/webresour...b3d54717be.pdf slightly ot, but i don't have all the equipment to do a full refill and pressure, i'm hoping i can just top up on top mount reservoir what i lose removing the front mount and then use the oe fuel pump to push out excess air from system
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12-18-2018, 12:23 AM	#10
climax_e92 Lieutenant 148 Rep 563 Posts Drives: E92 Join Date: Mar 2014 Location: Los Angeles 661 iTrader: (6)	So i finally got the coolant flush done on my 16 m4. My buddy is a shop foreman at an audi dealership and he used to machine to suck a lot of the coolant out, and used the machine to push it back in. Also did the intercooler reservior.
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12-22-2018, 04:10 PM	#14
climax_e92 Lieutenant 148 Rep 563 Posts Drives: E92 Join Date: Mar 2014 Location: Los Angeles 661 iTrader: (6)	Hey yeah it was about 3 gallons. Not sure what bmw's procedure would be. I read that they put it on a lift and disconnect hose by the radiator to drain the coolant. My buddy was trying to look for a place to disconnect so he can fully drain everything. Couldn't find a spot so he just used the machine. Took about 30 mins.
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