PSA on coolant leaks

fpvsportsguy · 06-09-2022, 12:33 PM

So for the S63 engine (and maybe even the n63), the overflow tank return hose seem to be a common failure point at one of the unprotected junctions. It's at the driver's side right underneath the side cowls. One end goes to the tank, one end goes to the top of radiator. Mine had a crack and I was losing a fair bit of coolant. First I thought it was the turbo coolant pipes underneath the engine cover, which is also a pretty common failure point due to heat cycling (mine was leaking a little bit, but not catastrophically), but after fixing that I still had a leak, which led me to do a thorough search and found the leak on the tank return hose. It's a pretty simple replacement, part number is 17127599571. Just thought I'd share.

JBF650 · 06-09-2022, 08:21 PM

thank you for sharing! I do periodically remove the vanity cover ( usually to wash down the dust and general washing cleaning of the engine bay every few months) to check for any obvious leaks etc etc . This is a good thread to share thank you, ill check these next time i wash the engine bay down.

cheers

Chief F1 Fan · 07-01-2022, 06:09 PM

I'm trying to figure out why my N63 motor keeps throwing off a "Low Coolant" warning when I open the hood, open the reservoir and it's full? Ideas? Faulty sensor? Should something be floating to the top of the level of the coolant?

EDIT: BMW's s#%tty manual sez nothing of an additional reservoir to fill with coolant, thank god for YouTube

Cadmus130 · 11-22-2023, 04:36 PM

So my 08’ 650i (N63) has just sprung a coolant leak. All I can tell is that it’s coming from somewhere in front of the engine and leaking directly underneath the middle.

It seems to only leaked when it’s hot after I’ve parked. Then it stops once it’s cool. After four days of this, my reservoir is finally dry. I’ve topped it off with distilled water per the suggestion from a mechanic I know and I have an appointment Friday to have it looked it.

I know it’s a shot in the dark, but does anyone have any suggestions? I’ve heard a lot of talk on here about these cars and leaks…

I just bought this car a week ago for cash, 134,000 miles, cheap. She runs beautifully, this is the first issue I’ve come across. Any help is appreciated!

06-09-2022, 12:33 PM	#1
fpvsportsguy New Member 25 Rep 25 Posts Drives: 2015 F83 M4 Join Date: Dec 2020 Location: Bay area, CA iTrader: (0)	PSA on coolant leaks So for the S63 engine (and maybe even the n63), the overflow tank return hose seem to be a common failure point at one of the unprotected junctions. It's at the driver's side right underneath the side cowls. One end goes to the tank, one end goes to the top of radiator. Mine had a crack and I was losing a fair bit of coolant. First I thought it was the turbo coolant pipes underneath the engine cover, which is also a pretty common failure point due to heat cycling (mine was leaking a little bit, but not catastrophically), but after fixing that I still had a leak, which led me to do a thorough search and found the leak on the tank return hose. It's a pretty simple replacement, part number is 17127599571. Just thought I'd share. Attached Images __________________ Rolling the dice with high mileage German cars 2017 G30 530i, 119k miles 2016 F33 428i, 85k miles 2015 F36 428i GC, 155k miles 2013 F07 550i GT, 125k miles
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06-09-2022, 08:21 PM	#2
JBF650 Second Lieutenant 116 Rep 248 Posts Drives: 2015 F13 LCI 650i Coupe Join Date: Sep 2019 Location: Sydney Australia iTrader: (0)	thank you for sharing! I do periodically remove the vanity cover ( usually to wash down the dust and general washing cleaning of the engine bay every few months) to check for any obvious leaks etc etc . This is a good thread to share thank you, ill check these next time i wash the engine bay down. cheers
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07-01-2022, 06:09 PM	#3
Chief F1 Fan Private First Class 51 Rep 119 Posts Drives: 650i xDrive Gran Coupe, 335xi Join Date: Mar 2015 Location: WNY iTrader: (0)	I'm trying to figure out why my N63 motor keeps throwing off a "Low Coolant" warning when I open the hood, open the reservoir and it's full? Ideas? Faulty sensor? Should something be floating to the top of the level of the coolant? EDIT: BMW's s#%tty manual sez nothing of an additional reservoir to fill with coolant, thank god for YouTube __________________ 2014 650i xDrive 2018 Mazda CX-9 2019 BMW 330xi 2023 911 Carrera S 7 Spd. ordered Last edited by Chief F1 Fan; 07-04-2022 at 08:13 PM..
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11-22-2023, 04:36 PM	#4
Cadmus130 New Member 104 Rep 8 Posts Drives: 2008 BMW 650i Join Date: Nov 2023 Location: South Florida iTrader: (0) Garage List 2008 BMW 650i [5.00]	So my 08’ 650i (N63) has just sprung a coolant leak. All I can tell is that it’s coming from somewhere in front of the engine and leaking directly underneath the middle. It seems to only leaked when it’s hot after I’ve parked. Then it stops once it’s cool. After four days of this, my reservoir is finally dry. I’ve topped it off with distilled water per the suggestion from a mechanic I know and I have an appointment Friday to have it looked it. I know it’s a shot in the dark, but does anyone have any suggestions? I’ve heard a lot of talk on here about these cars and leaks… I just bought this car a week ago for cash, 134,000 miles, cheap. She runs beautifully, this is the first issue I’ve come across. Any help is appreciated! Attached Images
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