Coolant leak?

[RuSport]

Ok, this happen to me as well. For me the blueish fluid leaking at the bottom of the oil pan came from bad o rings on the coolant connection pipe on the thermostat housing. The middle of the "V" on top of the engine was filled with coolant enough to drip down the back of the engine down to the oil pan. With a flashlight you can peak through some openings down the "V" to see if there is fluid in there. I changed the thermostat and connection pipe o-rings and it fixed the leak. Mine started after the car had been sitting for a while during the winter months. Hope that helps.

[CJAGZ]

Originally Posted by Mr. BMW

My car has been in storage since mid November. I drove it once over the winter and then 2 weeks ago I got it out, charged the battery and drove it a couple hours. I then got the oil changed and brake fluid flushed the next day and then brought it back to the storage spot.

I took it out for a drive today and notice a spot under the car about a foot wide where it had been parked the last 2 weeks. The spot is under the middle of the motor. At first I though it was water cause it looked clear but when I touched it, it felt oily and had a green color to it.

I called the dealer and he mention that the fluids were topped off and maybe some coolant spilled out or was overfilled.

How is that possible that it could spill out like that if it was overfilled?

Anybody have any ideas what it could be?

I parked it in a different spot and will see in a few days if the same thing happens.

Had the exact same problem as you had after storing mine for a few months in winter. Fired it up for the first time and got that same puddle. Sometimes the O rings on the overflow lines constrict or dry up. Since the power steering fluid and coolant both look extremely similar in colour (both greeny blue when fresh), it was tough to initially see because I was not looking. Next time on a cold start, look at the coolant overflow line leading to the tank and also look at the thermostat area. In my case, both the thermostat gasket and the O ring leading out to the overflow failed. Replaced and haven't had the problem since.

[FMLYSDN]

Originally Posted by CJAGZ

Had the exact same problem as you had after storing mine for a few months in winter. Fired it up for the first time and got that same puddle. Sometimes the O rings on the overflow lines constrict or dry up. Since the power steering fluid and coolant both look extremely similar in colour (both greeny blue when fresh), it was tough to initially see because I was not looking. Next time on a cold start, look at the coolant overflow line leading to the tank and also look at the thermostat area. In my case, both the thermostat gasket and the O ring leading out to the overflow failed. Replaced and haven't had the problem since.

Originally Posted by RuSport

Ok, this happen to me as well. For me the blueish fluid leaking at the bottom of the oil pan came from bad o rings on the coolant connection pipe on the thermostat housing. The middle of the "V" on top of the engine was filled with coolant enough to drip down the back of the engine down to the oil pan. With a flashlight you can peak through some openings down the "V" to see if there is fluid in there. I changed the thermostat and connection pipe o-rings and it fixed the leak. Mine started after the car had been sitting for a while during the winter months. Hope that helps.

Great post Gents

I'll have a look tonight.

[///My5UV]

Looks like coolant.
I got the thermostat replacement kit from ECS and it came with the O-rings for the pipes that connect the thermostat housing to the back end of the engine.
Then the little overflow pipe started leaking. All that is replaced and leaks stopped.
PS fluid is almost always darker and thicker than coolant, although coolant is pretty oily so it can be confusing.
WW fluid leaks from the side and is always thinner than either.

BTW, I put the end of a sock on my PS fluid caps so that WHEN it seeps it doesn't make a mess on the rest of the engine.

[FMLYSDN]

Originally Posted by ///My5UV

Looks like coolant.
I got the thermostat replacement kit from ECS and it came with the O-rings for the pipes that connect the thermostat housing to the back end of the engine.
Then the little overflow pipe started leaking. All that is replaced and leaks stopped.
PS fluid is almost always darker and thicker than coolant, although coolant is pretty oily so it can be confusing.
WW fluid leaks from the side and is always thinner than either.

BTW, I put the end of a sock on my PS fluid caps so that WHEN it seeps it doesn't make a mess on the rest of the engine.

Ah yes. I have a sock too

[Mr. BMW]

Originally Posted by RuSport

Ok, this happen to me as well. For me the blueish fluid leaking at the bottom of the oil pan came from bad o rings on the coolant connection pipe on the thermostat housing. The middle of the "V" on top of the engine was filled with coolant enough to drip down the back of the engine down to the oil pan. With a flashlight you can peak through some openings down the "V" to see if there is fluid in there. I changed the thermostat and connection pipe o-rings and it fixed the leak. Mine started after the car had been sitting for a while during the winter months. Hope that helps.

I took a look last night. I don't see any coolant anywhere and all my hoses look clean and new so I don't think my issue was coolant. I think my issue was power steering fluid.

[Helmsman]

Originally Posted by Mr. BMW

I also check the coolant level and I see coolant in there but I can't figure out what the level is supposed to be at.

Once you open the coolant cap there is a red floating stick. Believe there is guidance on the holder, if not there are max/mix mark on the floater.

Cheers

[Mr. BMW]

Originally Posted by Helmsman

Once you open the coolant cap there is a red floating stick. Believe there is guidance on the holder, if not there are max/mix mark on the floater.

Cheers

Yeah, so my float is level with the top of the opening. It doesn't stick up out of it so I think I need to add some.

I found this video that was helpful..

[Helmsman]

Originally Posted by Mr. BMW

Yeah, so my float is level with the top of the opening. It doesn't stick up out of it so I think I need to add some.

I found this video that was helpful..

Yep, there you have it mate.

[CJAGZ]

Originally Posted by ///My5UV

Looks like coolant.
I got the thermostat replacement kit from ECS and it came with the O-rings for the pipes that connect the thermostat housing to the back end of the engine.
Then the little overflow pipe started leaking. All that is replaced and leaks stopped.
PS fluid is almost always darker and thicker than coolant, although coolant is pretty oily so it can be confusing.
WW fluid leaks from the side and is always thinner than either.

BTW, I put the end of a sock on my PS fluid caps so that WHEN it seeps it doesn't make a mess on the rest of the engine.

The sock gives it a nice touch when you go to show off the beautiful motor to all your friends or colleagues good call though. I seem to have to wipe the reservoir area down every month or so from a small sweat that it creates.

[///My5UV]

I should use a black sock when showing off the car to business colleagues.

[Ngilbe36]

I found my leak. Seems like it is coming from this sensor interface, which doesn't make sense since this is an oil pressure switch according to the diagrams.

Edit: Looking again, it seems like it could be coming from the other connection point to thermostat housing. The vent pipe.
+ Diagram.

Edit #2 @WalkerM3 Said to check this on the first page. Gold star for you.

[BAMFM3]

Originally Posted by Ngilbe36

I found my leak. Seems like it is coming from this sensor interface, which doesn't make sense since this is an oil pressure switch according to the diagrams.

Edit: Looking again, it seems like it could be coming from the other connection point to thermostat housing. The vent pipe.
+ Diagram.

Edit #2 @WalkerM3 Said to check this on the first page. Gold star for you.

Sorry to bump this thread, but really wanted to thank everyone as this helped me figure out my leak situation.

Seriously, these forums are life savers (they also helped me diagnose my EDC module failure!)

[dpilat8588]

Originally Posted by Ngilbe36

I found my leak. Seems like it is coming from this sensor interface, which doesn't make sense since this is an oil pressure switch according to the diagrams.

Edit: Looking again, it seems like it could be coming from the other connection point to thermostat housing. The vent pipe.
+ Diagram.

Edit #2 @WalkerM3 Said to check this on the first page. Gold star for you.

Is it possible to replace this coolant hose without removing the plenum?

Also, did coolant come pouring out when you removed the bad overflow hose? Or did nothing come out, making it a mess-free procedure?

[Ngilbe36]

Originally Posted by dpilat8588

Is it possible to replace this coolant hose without removing the plenum?

Yes, it will just be much tighter to work with. The reason I took mine off was that I was still trying to find the leak.

[dpilat8588]

Originally Posted by Ngilbe36

Yes, it will just be much tighter to work with. The reason I took mine off was that I was still trying to find the leak.

Ok...did coolant come pouring out of either end when you removed the bad hose? I am trying to determine if I need to drain the coolant system to avoid making a mess.

[Ngilbe36]

Originally Posted by dpilat8588

Ok...did coolant come pouring out of either end when you removed the bad hose? I am trying to determine if I need to drain the coolant system to avoid making a mess.

I'm trying to remember. Its up pretty high on the reservoir, maybe a little comes out...sorry I forget my exact procedure on it. Good luck!

[dv13]

Originally Posted by CJAGZ

The sock gives it a nice touch when you go to show off the beautiful motor to all your friends or colleagues good call though. I seem to have to wipe the reservoir area down every month or so from a small sweat that it creates.

https://www.m3post.com/forums/showthread.php?t=1520657

Options for those using socks to stop the weeping/spraying from the PS reservoir cap. The replacement is very cool, or if you are looking for a cheaper option the $1.50 o ring replacement is hard to beat. And it works beautifully until the o ring wears out after a few years.

[Mimmer]

Any parts number for the fixes?
O ring and tube? Thanks! mines super low.... So there a leak somehwere but havent seen it drip to the ground... I put basically 1 whole quart with mixed half water. Thr stick was so low it didnt eve pop up.... Last top off was 2 years ago ... And only added half quart.