Expansion Tank - 9 months old and leaking already

[CERF04ZHP]

Bought from Bavarian Auto. on 03/30/12 - Decided to get the JL Germany tank instead of OEM to save a couple bucks (kicking myself in the ass now). Installed first week of April 2012, approx. 18k miles ago. Have noticed over the last few weeks that the level in the tank has dropped, and discovered a leak at the seam where the top part of the tank attaches to the lower portion. Two questions:
1.) What is the warranty on this item? I am hoping that because it is less than a year old, it is still under some sort of manufacturer's warranty. Will BavAuto honor a replacement? I will be happy to pay the difference for an OEM tank, if that is the case.
2.) It's Sunday afternoon, they're closed. I have to work tomorrow and all week. Earliest I will be able to replace is Saturday morning, which is 500 miles from now. Is there any sort of temporary solution to slow the leak? I am having to add coolant almost once/day as the low coolant light comes on. Hate pouring expensive BMW coolant/distilled water in just to see it all leak out.
Thanks guys!

[kayger12]

I should hope BavAuto would cover it.

As for short term fix-- not many options.

I'd also be concerned about continuing to drive it with these winter temps. Every heating/cooling cycle is most likely making that crack worse.

If you don't have a choice but to drive it, I'd keep my eyes glued to that temp gauge.

[CERF04ZHP]

I should hope BavAuto would cover it.

As for short term fix-- not many options.

I'd also be concerned about continuing to drive it with these winter temps. Every heating/cooling cycle is most likely making that crack worse.

If you don't have a choice but to drive it, I'd keep my eyes glued to that temp gauge.

Thanks. One could only hope they cover it. Their customer service is pretty decent, I would imagine they would be pretty accommodating, I'm not being unreasonable here. Eyes will be fixed to the lower right corner of my gauge cluster.

[Hermes]

how cold is it by you right now? I would just top off with straight distilled water and maybe some water wetter until you get it solved

[Johal E32]

how cold is it by you right now? I would just top off with straight distilled water and maybe some water wetter until you get it solved

This. When my tourings lower radiator hose started to leak.. I used some water to top it off until the new parts came in..

[CERF04ZHP]

how cold is it by you right now? I would just top off with straight distilled water and maybe some water wetter until you get it solved

It's about 28. Warming up though - 32 Mon., 39 Tues., 50 Weds. I'll just deal with topping off as needed.

[wsmeyer]

That really sucks. One of the drawbacks of non OEM parts is that if something goes wrong you'll always wonder if it was just bad luck or a crappy part.

As others have said, there really aren't any good short term solutions. There's lots of stop leak stuff at the auto parts store for tires, oil, coolant; pretty much anything. IMO, they should all be on an end cap way in the back with a big sign "For dire emergency only!"

As for the coolant, they tell you to do a 50/50 mix because it's easy to do and will cover almost everyone in the US. Check out this chart on wikipedia:

http://en.wikipedia.org/wiki/Ethylene_glycol

A 50/50 mix has a freezing point of -30F.

If what you had in your system was 50/50, and 80% of that leaked out and you filled it back up with straight water, you'd have a 10% solution and the freezing point would be 25F.

There is a downside to topping it up with water though, there's no simple way to get back to 50/50 after the repair. After you drain the radiator there will still be an unknown quantity of water in the engine block with an unknown concentration. A good guess would be to re-fill the radiator with a mix of 70% antifreeze / 30% water. From there you would have to drive the car to mix it with the existing stuff, measure the concentration, and then suck some out and replace it with some straight water or antifreeze. Then drive some more and keep repeating the process until you get to 50/50. Or you can just keep topping it up now with 50/50 and skip all the hassles.

If you're going to continue driving the car, be certain to check the coolant level every time before starting the engine. The worst case scenario you face is that enough coolant leaks out while the car is sitting that the water level drops below the water pump. If this happens and you get in the car and drive off, the water will not be circulating and the engine will overheat and self destruct without the temp gauge ever moving.

If it were me, I'd rather have my car break down at my house or my office so I'd check the coolant level and top up as necessary. Then start the car and either let it idle or drive around the block a few times until the engine warms up. When it gets to operating temp the thermostat opens up and the coolant begins circulating, this is when you start seeing the temp gauge move up to the middle and is also the temp that the cooling system is going to try and maintain. This would also be the maximum pressure inside the radiator, and (hopefully) if your expansion tank is going to completely split, this would be the most likely time for it to happen.

[Hermes]

There is a downside to topping it up with water though, there's no simple way to get back to 50/50 after the repair. After you drain the radiator there will still be an unknown quantity of water in the engine block with an unknown concentration. A good guess would be to re-fill the radiator with a mix of 70% antifreeze / 30% water. From there you would have to drive the car to mix it with the existing stuff, measure the concentration, and then suck some out and replace it with some straight water or antifreeze. Then drive some more and keep repeating the process until you get to 50/50. Or you can just keep topping it up now with 50/50 and skip all the hassles.

or you can pull the block drain plug...

but it's a huge PITA

[echo46]

I tried buying the same one to save some bucks and it never fit correctly. I had slights leaks that drove me out of my mind. Finally just bought OEM and it fit perfect.

[wsmeyer]

or you can pull the block drain plug...

but it's a huge PITA

Good call. I didn't even know that thing was there.