God#%^*!!! Expansion tank!!!
 

So having just replaced my radiator, I thought I was GTG.

However a routine inspection under the hood revealed coolant splatter around the expansion tank. It appears to be coming from the seam where the upper and lower tank join together. Arrggghh!!!

I checked parts prices and the original BMW part is $30-$40 more expensive than replacement brands. Is the BMW original $30 or more better than the other replacement brands (Meyle/MTC/Vaico)?

Do I need to replace the coolant level sensor with a new one?

Oh, and any tips on removing it without breaking the transmision thermostat?

first - put your car info in your signature.

second - BMW doesnt make parts per se, they source them from suppliers. Suppliers then turn around and sell them with their brand on the secondary market. Other manufacturers take the product, reverse engineer it, and sell it on. SOmetimes, BMW ships back their surplus parts and they sell those ( you can tell when the roundel is ground off)

I can tell you from experience, to ALWAYS avoid MTC (perhaps it stands for Made in Taiwan or China - NOT THAT THERE IS ANYTHING WRONG WITH THAT)...

Meyle is a pretty reputable supplier and so is VAICO (they actually make the real DISA units IIRC)

I've never done on ET replacement (dont overfill and they dont burst ....knock on wood).

Assuming you have a 3.0, you can also check out the e46 forums for reviews of the various tanks.

Hey J, my car info is in my sig. 04 X5 3.0 automatic.

Thanks for the feedback on MTC. I do have Meyle HD for my tension strut bushing now, and though they are a reputable supplier in general, I learned it pays to check around as sometimes there is a particular supplier to go to for certain components. For example, Meyle also offers tie rod assemblies but the go-to for this part is Lemforder as they are the actual OEM. Thanks for the info on Vaico, did not know that and it will come in handy when my DISA goes.

So would you happen to know who is OEM for this? I tried to check reviews on e46fanatics and it appears some replcement brands do have problems, but have not come across who is OEM yet.

Lucky you havent had to do it, I had to do a tank replacement on an E46 and a tank removal on my E53 when I replaced my trans oil cooler. Broke the damned trans thermostat both times!

MTC and Üro are 2 brands to stay away from without a doubt....that stuff is Sh!t, and their price point being far below others reflects that.

Why did you not do a coolant tank with the rad?? Moreso if you have yet to do a coolant tank/coolant system overhaul...that would have been about the best time ---would have prevented the predicament you're in now. :thumbup:

Edit: and for the oem...it's always the one that says "genuine BMW" OEM / Performance Parts for Audi, BMW, Mercedes Benz, Mini, Porsche & Volkswagen - ECS Tuning

BMW has been effectively using the same design on the ET since at least the 90's. My guess is that they have several suppliers at this point. Vaico/Meyle seem like safe bets. Try furious method and see if there are any others that make them. Graf and Behr make a lot of cooling system components.

Remember, DONT OVERFILL IT!

X5SND, I was of the impression that the expansion tank was just replaced when I go the truck (about a year and 15t miles ago). That's why I didnt change it out when I replaced the rad. It crossed my mind though...shoulda listened to intuition!

Thanks too for the feedback on Üro and MTC. Not that experienced with BMW yet honestly, so feedback like that helps a lot!

On the OEM, I got what you mean and thanks for that, but in cases when the manufacturer who makes a particular part for BMW is known (like with Lemforder for tierods) and I dont mind going with that brand. For expansion tanks, would you happen to know who makes the BMW-branded ones?

J, yeah that seems plausible. Will check out the other manufacturers you mentioned and reviews too. At least the brands to avoid are clear, it's a start!

You are in So.Cal, contact Max at oembimmerparts, he can get you that part within a couple of days. Meyle is a good brand, and also Behr, but I'm not sure they make coolant tanks.

i got the OE expansion tank in May of 2013 (original was seeping at the seams between the top and the bottom portion), replaced it without much drama, now we are in November of 2013, and the tank is seeping again at the top/bottom seam (started sometime in September)... Original Equipment, bearing BMW logo... was spanking brand new in factory box...

since i still have the old unit, I wonder, if I could split the top and bottom open, and then reseal them together, using some crazy sh!t thermoresistant, waterproof glue...

has anyone done that?

If you mean #8 in the diagram below...then it depends if the one in your old ET works. If it does, when you replace the tank, remove the old one and screw it into your new tank.

If you didn't know...you can always tell when a part comes with other parts when they are bracketed together...for example...#7 is bracketed with #5 which means that it comes with #5 (as well as being able to be purchased separately using its BMW part nbr found in the part nbr index below the diagram).