Coolant leak
 

Well, I checked both forums and couldn't find this specific leak so I am hoping you all can help me out.
The other day I was at work and walked past my car and noticed a puddle under the engine more to the passenger side front. I moved my car and checked later that day and sure enough another little puddle. It felt slimy like mineral oil so I new it was coolant. I jacked car up and dropped the plastic cover exposing the bottom of the engine compartment. I found the leak!! It is a thick hose connecting to the bottom of the radiator. On the passenger side. Anyone ever fix one or how to fix this. Parts, instructions ect....
I took a picture of the leak. Thanks everyone

Also. Is that red valve a way to drain the coolant out so I can replace

Are you talking about part #3 on this diagram?

That's the lower radiator hose for $36.

Txtaz. The diagram isn't coming up. Can you send again. Btw. It is the lower hose, is it easy to fix and can I drain the coolant out of the red valve that is in the picture? Thanks again

You can search for the diagram on http://getbmwparts.com/

I haven't drained the radiator before on my car so someone else will need to chime in here.

When I have done radiators in the past, I've always cut the hose and drained it. It makes it easier to remove the hose when it's cut in half.

In the past I've drained BMW rads using a bolt on the rad or by pulling the coolant level sensor on the lower part of the rad.

Here are the TIS instructions for draining and refilling.

The engine drain bolt tightening torque is 25Nm or 18 ft-lbs.

As for coolant. Do I have to use oem BMW coolant or can I use a different brand from a regular auto parts store. Thanks

Use OEM BMW coolant, you need two jugs and mix it 50/50.

The blue BMW coolant is made by Glysantin which all the German manufactures use. It is pH balanced, nitrate free, phosphate free and has very good corrosion inhibitors. Using BMW coolant will ensure your gaskets last as long as possible (ie you don't want to case a $2,000 premature engine coolant pipe leak by using cheap coolant). Prestone and other non-phosphate free coolants can be hard on BMWs rubber gaskets.

Just got back from stealership and paid 81.00 for the hose and antifreeze, first thing in the morning I will replace and fill. I will time myself and post difficulty after I am done. Looks to me like a 30 minute job but we will see.

Hope you are all out there, it's Sunday and dealership is closed. So it was an easy fix, you can replace the lower hose from top and without jacking car up and getting underneath. Found the leak!!!! It wasn't the hose!!! But I am glad I am replacing it anyway. The leak is coming from the temp sensor. I guess the green o ring has shrunk and failed. I put back together and filled with water and ran to flush the green antifreeze that must have been done from previous owner. I noticed the dripping coming from temp sensor, I wiggled it and I am certain. The problem is, it is Sunday, BMW closed, can I get an oring from local auto store that will fit and thick enough to seal?

If you think you can quickly pull and replace the sensor without draining the system then it would not hurt to try changing just the o-ring.

I would try the new o-ring, refill the system and if it still leaks grab a new sensor from the dealer ($25) tomorrow and replace it without draining the system.

Here is a shot of what a new sensor looks like if you want to see how thick the o-ring should be for reference.

This same exact thing happened to me about three weeks ago. It is the Temp sensor and all I had to do was replace the Temp Sensor O-Ring with one from Home Depot. The E46 has the same exact temp sensor and the O-rings fail all the time. I found a DIY on the internet and the correct O-rings to purchase are the Danco #31 O-rings that come in a pack of 10.

http://lh4.googleusercontent.com/pub...RrbnhXijRA1rGN

I'll stop by later today and give you one Superhart, since you live about 3 minutes away... All you have to do to replace it is unclip the temperature sensor from the wire harness and lift it out of the top of the engine bay. Remove the old O-ring and place this one on there in its place. No leaks ever again! You should have called me yesterday before you did all of this because I would have given you the hookup!

Thanks DBLAZE for stopping bye and hooking me up with some o rings, let's hope I won't need them just yet.
Well, BMW originally said that my lower radiator hose was leaking and wanted to charge me 265.00 for complete job. After taking the hose off myself I found that the hose was fine and the leak was the o ring on the temp sensor, a measly 2 dollar rubber gasket. I will return that lower hose to dealership for my money back, after filling and topping off with bmw antifreeze I ran car and got her up to temp, bone dry! Thanks to everyone who helped me out on this

Just an update

two weeks and car is dry, no leak detected and water level is stable

I had just posted this on the 17th... http://www.bimmerfest.com/forums/sho...d.php?t=582161

This is all great info, I am happy that you guys are posting the cause and fix. The simple O ring is the way to go. If the sensor is good and the hose is good I wouldn't replace either since it is simple enough to do if and when they actually fails. The O ring is obviously the weak link in the system. Another BMW engineer fail!

Certainly if I ever have a lower leak this is the first part I would check.

+1 Amen we are all on this forum to help and talk these issues through

Funny i came across this , they Told me $285 bucks to swap the lower radiator hose on my 750LI .. I have just replaced the hose ($35 bucks later ) and still leaking , I Knew for sure the dumb A$$ tech i spoke with was wrong as i told him face to face it can't be the house and could very well be the sensor O ring . Thanks for the info guys .



So Home Depot has these O rings ? I need to pick one up in a bit or should i just buy the sensor from BMW Tomorrow ?
Thanks again fellas

Here's the illustration in case everyone comes up with this problem and needs to use it ..
http://bmwfans.info/parts/catalog/E6...m_water_hoses/

http://img217.imageshack.us/img217/4586/mtu2mzy1x3a.png

If I was you I would start with the O-Ring. If you are not getting sensor errors then probably it still is working properly, you just have a leak? Here is the O-Ring at Home Depot so nicely posted previously, off to the right you can check the local store availability.

It is only $2.27 for a pack of 10, it is the best way to start!

http://www.homedepot.com/h_d1/N-5yc1...1&ddkey=Search

Just finished installing the O ring and leak gone ... Just took it for a ride and bone dry .. Thanks again fellas . But I'm thinking of grabbing a sensor and keep it in the car just in case :thumbup:

Here's the difference ... New rings fits nice and tight . (Green OEM O ring )

http://img840.imageshack.us/img840/2...ooglecom1s.jpg


http://img37.imageshack.us/img37/506...googlecomh.jpg

Glad I could be of assistance...:thumbup:

Just wanted to post a quick thank you note to all of you (especially Superheart, Yorgi, and Dblaze) for this diagnosis and DIY guide. Had the 6 in for a routine service at BMW yesterday and they said they found a coolant hose leak and quoted me $335 (for new hose, sensor, other parts, and labour). After reading this post, I stopped by home depot, replaced the o-ring on the sensor, and what do ya know!! fixed for less than $3 bucks. Thanks again.

YOU GUYS ROCK!!!!!

haha Happy for you man :thumbup:

No problem. Glad our leaky cars helped you out:)

I wonder how the Home Depot O ring will hold up to the heat?
Can I just pull sensor out or will the coolant spill all over? Thinking about changing out just as a precaution..what do u guys think?

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