# BMW n52 1 series (e82) Overheating!



## jam128 (Dec 21, 2020)

I own a 2011 bmw 128i - n52 with 80k miles on it. I was driving one day and then i got a yellow low coolant dashboard sign. I continued driving for 10 minutes without noticing anything odd then parked for 30 minutes. I did not check for coolant levels when i drove off AGAIN. After 20 mins driving i noticed steam coming out the hood so i pulled over and shut the engine. NO engine overheating sign was displayed at all. I checked coolant and none was inside. There was a big leak visible and i don't recall i heard the radiator fan operational before shutting off the engine. Then the next day i sealed leak and filled new coolant but noticed a service engine light SES come on. Did i do damage to the engine  ?? What could have caused the leak ? water pump was working fine.


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## Doug Huffman (Apr 25, 2015)

Vacuum filling is recommended now for E82 N52 128i. Without vacuum filling the water pump may be air bound. Without vacuum filling there may be trapped air voids without fluid flow through them to purge the air.

new*TIS*
Home / BMW E82 128i Coupe / Repair Manuals and Technical Data / 17 Cooling / 17 00 Cooling, check /
*17 00 039. Bleed and fill cooling system with vacuum filling unit*


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## mr_bean (Mar 20, 2009)

Where was the coolant leaking from?
Have you had the error codes scanned to see why the SES light is on?

Side note, you can bleed with the vacuum method.
Open the filler cap and loosen (don't remove) the little bleeder screw next to it.
Fill with coolant to the top and close the screw when it stops bubbling. Put the reservior cap back on.
Turn the car on without starting the engine
Set the heat to max with the fan speed on min
Hold down the accelerator pedal to the floor for 10 full seconds. You should hear the water pump kick on, it's quiet though. Release the pedal.
Wait 10-15minutes until the pump stops.
Check the coolant level and top off as needed.


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## jam128 (Dec 21, 2020)

Doug Huffman said:


> Vacuum filling is recommended now for E82 N52 128i. Without vacuum filling the water pump may be air bound. Without vacuum filling there may be trapped air voids without fluid flow through them to purge the air.
> 
> new*TIS*
> Home / BMW E82 128i Coupe / Repair Manuals and Technical Data / 17 Cooling / 17 00 Cooling, check /
> *17 00 039. Bleed and fill cooling system with vacuum filling unit*


sounds about right, would try that asap.


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## jam128 (Dec 21, 2020)

mr_bean said:


> Where was the coolant leaking from?
> Have you had the error codes scanned to see why the SES light is on?
> 
> Side note, you can bleed with the vacuum method.
> ...


There was a huge leak from the hose that connects to the radiator on the driver side. There wasn't any breaks though, only a loose hose. I'll try bleeding the system in an effort to avoid overheating again. Will scan car for SES soon.


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