Hi all! I have a R56 2009 base model that startet leaking coolant - and lots of it!

Video: https://files.catbox.moe/7ei21g.mp4
(here's a mirror if that video doesnt load)

Can somebody help me figure out if I need to order a gasket, housing or thermostat? I get to work on it in few days.

Thank you.

 

I'm struggling to figure out the exact location of your video in the engine bay. Below shows diagrams of your coolant hoses, T-stat housing, radiator, reservoir, coolant pump, and crossover pipe.

My wild guess is a leaking water pump.

 

Great, thanks for the diagrams.
I made another video with the engine off.
https://files.catbox.moe/qmv4un.mp4

It could be the thermostat housing.

 

If coolant is pooling on top of the transmission, it's leaking from thermostat-housing.

FYI - If replacing the thermostat-housing, make sure you replace the water-pipe along with it also.

 

@GsxR1000 Thanks! you mean this pipe from above diagram, right?

 

You are correct. The leak is from the thermostat housing.

 

Following because my 2011 R56 Base is leaking a lot this week. The reservoir had gone empty twice on after short trips. Backing into my driveway, it leaves behind two lines of drips. 🤦

 

As mentioned, coolant on top of the transmission would lead me to believe thermostat.

Drips on the passenger side would point to water pump.

 

Yeah, it was the thermostat. The housing is made of plastic and cracks at some point (mine lasted 15 years)
https://www.realoem.com/bmw/enUS/sho...diagId=11_3931

 

https://www.northamericanmotoring.co...placement.html

Yep the early ones were all plastic and then later in the R56 life cycle they switched to all metal outside. My 2012 has a metal one. My 2007 R56 Cooper S had the plastic and it leaked at the bottom bolt and had a hairline crack.

 

Could also be a leaking crossover pipe where it connects to the water pump.

 

Thank you! Yes the discussion and diagrams here are very helpful! I am checking to see if I can DIY. 😬

 

Thank you! I can't see a cross over pipe from above and will check when I can get under again. 😳

 

It may help to remove the air intake pipes and air filter box and to use a telescoping mirror from above.

 

If over the transmission
-thermostat
​​​​​​-crossover pipe
-bad hose to Thermostat
I believe there are 5 of them

although a noble and helpful suggestion, that mirror will not be able to get you to where you’ll see the root of the problem


of your handy, take of the air filter housing (top and bottom)

maybe if your lucky, a flashlight from front drivers to Thermostat area, but that will only show that it’s wet.

I feel your pain
I’m in the middle of replacing my Thermostat, crossover pipe and water pump

Unfortunately, I’m still wrestling with the removal of air intake so that i can properly access the crossover pipe.

project delayed yesterday and today. Hope to be back to it tomorrow

big job
I hope you locate the source, a leak of anykind can really ruin your day.

 

Coolant leak is a secondary problem that I am dealing with. A misfiring and P0300 is going to keep me from passing the emission tests. Even if I can fix that issue and clear the codes, I still need to drive 100 miles to create new data for the emission tests. With the coolant leak, I wont't be able to go that far. The leak from the thermostat housing was dealt with a few years ago, currently things are dry on that side.

Considering all the work that I need to do under the hood, I removed the intake box and silencer and swap in a silicone pipe on the TB, connected to the MAF, and then a cone filter. That way I can remove the entire assembly just by loosening up one worm clamp and MAF connector. It is easy on the Non-S. What part of the intake is holing you back?

 

Use a code reader capable of retrieving BMW codes and post them.

 

Thank you! BimmerLink and I need a newer BT dongle.

 

Multiple BMW codes fall under the wide umbrella of generic code P0300. The much more precise BMW codes will generally substantially shorten the time and effort required to identify and fix MINI problems.

 

ya man you can DIY the thermostat. .....get an OEM thermostat from ECS Tuning!!! Thats a critical component. Dont use some aftermarket junk.