Expansion tank

I will start off with saying I replaced my Thermostat and water pump a few weeks ago. I inspected my expansion tank and it looked in tip top shape well last night I discovered otherwise. I was driving home from work and looked down to discover my temp gauge was in the red....idiot light on! Pulled over and took a look. Didn't see anything so I let the car cool and only made it another 1/4 mile. Stopped got out, looked under the car and saw coolant running out . This afternoon I pulled the air intake and box to find a MASSIVE crack in the tank just below where I could see.

I will say getting the tank out wasn't difficult, just a little tricky. The hoses didn't want to pull off easy and when I pulled the tank, the bracket came with it. And yes I pulled the release clips. This is a fairly straight forward job that wasn't too challenging. I was able to do it without even getting the car off the ground.

Here is the tank:

Great post, will read again.

ECS sells cooling kits for out cars at a reasonable price. Buy the best kit you can afford, because inevitably, you'll either be fixing your car somewhere where you like, as in your friend's shop, or somewhere very inconvenient, like on the side of the freeway. BMW cooling systems fall apart at the 100,000 mile mark so budget, set the money aside and get prepared to spend.

Originally Posted by lucky_doggg7

ECS sells cooling kits for out cars at a reasonable price. Buy the best kit you can afford, because inevitably, you'll either be fixing your car somewhere where you like, as in your friend's shop, or somewhere very inconvenient, like on the side of the freeway. BMW cooling systems fall apart at the 100,000 mile mark so budget, set the money aside and get prepared to spend.

I agree! I think I have replaced all but the radiator so I should be good for a good while now. FYI, for those of you who try this and can't get the tank out. Use a claw hammer and pry upward on the cap against the core support and it should pop right out. I know some might disagree that this will cause a break somewhere, but it worked for me.

2 other pointers:
1 just replace the cap or the rings, it's not worth the extra trip just because you wanted to save $10.
2 to get everything to seat easily and proper, use just a little KY lube on the male end or something to that affect and all the hoses will reconnect easy. Again, very unorthodox but hey I got it back together and started in 15 min.

Lastly, I would like to thank all who did DIY write ups as it made this a near fun job.

If any have questions on this job, feel free to ask or pm me.

Hey im looking at buying my expansion tank and im seeing a meyle tank for 42.53 and a coolexpert tank for 66.16 what do you guys think?

I pieced out a kit from ECS since i had done the thermostat and i went ALL OEM..tank,sensor,cap,hoses.,dont cheap out

Originally Posted by erice46

Hey im looking at buying my expansion tank and im seeing a meyle tank for 42.53 and a coolexpert tank for 66.16 what do you guys think?

On this, I would go with a direct OEM replacement. I would not cheap out at all. Even though it isn't difficult to do, I would rather by once and cry once and not have to do it for another 80-100k

I don't need to open a new thread for this question: how much coolant would I need when I replace expnasion tank ONLY? I understand that I would need more than it comes out while draining before replacent, because I would loose some during bleeding procedure. So, either would do for me - how much did you drain before OR how much did you add after ET replacement (roughly)?

Thanks!

Originally Posted by daki_bmw

I don't need to open a new thread for this question: how much coolant would I need when I replace expnasion tank ONLY? I understand that I would need more than it comes out while draining before replacent, because I would loose some during bleeding procedure. So, either would do for me - how much did you drain before OR how much did you add after ET replacement (roughly)?

Thanks!

I would say have at least 1 gallon at the ready. But more would be better. You will loose a lot from the hoses at well as the tank.

Thanks kowalzekc, I didn't imagine there would be that much spillage.

Originally Posted by daki_bmw

Thanks kowalzekc, I didn't imagine there would be that much spillage.

There are a few hoses attached to the tank on the side and bottom. They are longer and one is fairly large. Plus just buying a gallon is cheaper than the quarts. Also remember if you are buying the BMW blue, you will have to cut it with water.

Originally Posted by kowalzekc

There are a few hoses attached to the tank on the side and bottom. They are longer and one is fairly large. Plus just buying a gallon is cheaper than the quarts. Also remember if you are buying the BMW blue, you will have to cut it with water.

Of course, 50/50 mix of BMW blue and distilled water. Actually I dont have much choice - my dealer has only 1.5 L (81 22 9 407 454) containers and it's bloody expensive @ 10€ ($12.8), so that's around $13 for a just a tad more than 3 quarts (3 litres) of 50/50 mix.

Is there anyway I can repair the tank or it's better to buy a new one.

Just get a new one from the dealership. By once cry once. If you try and repair it chances are it will just crack in another spot sooner than later.

Def go with oem expansion tank. I would follow up with a compression test. if you repair the tank and your head gasket was compromised it can push pressure back and find a new weak spot, radiator, hoses, etc. also non hardening rtv dabbed on inside of hoses will stop a steady drip when you reassemble.