[ahhllen]

Hello. I recently started getting the low coolant warning on my dash. I fill it up with about 2-3 liters of 50/50 coolant then next day, i get the same warning. I filled it up with another 2-3 liters of distilled water which only last about a day before I get another warning.

Could this be the usual expansion tank leak? I will remove the undercarriage this weekend to see where it is coming from. I do get a wet spot on the floor underneath the passenger side after i park from a drive. No visible white residue can be seen looking at the engine bay from the top. It seems like it only leaks when certain pressure is reached in the cooling system and then the whole expansion tank is emptied.

Has anyone had this issue? Most of the threads i searched seen only has a slow leak..

I've been driving it for about 3 days now since it's my only car and I just refill it as soon as I park.

[BeastMode335i]

Well it could be quite a few things, but check all ur hose connections and I'm sure you'll find the root of the issue..

[ahhllen]

Originally Posted by BeastMode335i

Well it could be quite a few things, but check all ur hose connections and I'm sure you'll find the root of the issue..

Would you recommend a coolant dye or a certain brand to make the leak easier to see?

[BeastMode335i]

Originally Posted by ahhllen

Would you recommend a coolant dye or a certain brand to make the leak easier to see?

Hmm, i'm a bit old school for matters like this and would first remove all the plastics in the way, grab a flash light and get to scopin out the area.. It may be something very easily identified, but if after looking through all the hose connections, you still don't see it, I'd probably go through the hoses and check one more time.. Those dye kits work, but IMO it's wasting money unless you really looked down through there and can't find it..

[BeastMode335i]

Check your expansion tank, upper hose that's under the OFH, and all the other connections up top.. If nothing found, then i'd slide under the car and check the water pump area and turbo coolant hoses..

[steertrak335i]

I had the same recently. It turned out to be the waterpump with a small crack in it . Good luck

[ahhllen]

Originally Posted by BeastMode335i

Check your expansion tank, upper hose that's under the OFH, and all the other connections up top.. If nothing found, then i'd slide under the car and check the water pump area and turbo coolant hoses..

Thanks for the diagram, I'll check those areas and hopefully find some white coolant residues on one of the hoses or expansion tank.

Originally Posted by steertrak335i

I had the same recently. It turned out to be the waterpump with a small crack in it . Good luck

Was it draining out only a few liters at a time as well? How did you diagnose it was the water pump?

[ahhllen]

It's def leaking somewhere near the belt at the very bottom. My whole undercarriage is soaked.

[ahhllen]

It looks like it's coming from the coolant outlet hose under the OFH. There's def oil around it and probably coolant since there's a small puddle right under the hose. It stopped dripping just a few minutes after i took off the undercarriage since the car got cold. I filled up the coolant reservoir but it hasnt leaked since.

[ahhllen]

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[ahhllen]

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[JuniorB]

Get a power washer on that engine already!

[ahhllen]

Started up the car and saw coolant drip right away from the Outlet Coolant Hose (p/n 11537541992). Anyone know of a DIY to replace this part?

[ahhllen]

Found this replacement from a thread with the same issue..

http://m.ebay.com/itm/182218057115

http://www.e90post.com/forums/showthread.php?t=1117422

Has anyone else tried it before? I wouldnt mind replacing the whole hose but it seems like it would be a PITA.. and the aluminum piece looks nice lol.

[BeastMode335i]

Originally Posted by ahhllen

Found this replacement from a thread with the same issue..

http://m.ebay.com/itm/182218057115

http://www.e90post.com/forums/showthread.php?t=1117422

Has anyone else tried it before? I wouldnt mind replacing the whole hose but it seems like it would be a PITA.. and the aluminum piece looks nice lol.

That's exactly what I thought it was going to end up being, and had already planned on linking you to that item on eBay.. It's a very common failure point on these motors, and many people, myself included, have bought that eBay part to fix this issue.. You can get to it without removing much of that stuff up there, it's just a tight squeeze.. And be careful when removing it, because if it did like mine and started to disintegrate, some of those pieces can actually fall down into the engine and you'll have to flush it all out, which is not fun.. Probably a good time to do a coolant flush anyways, supposing you haven't done one recently..

Also, make sure when seating the new part that the o-ring doesn't crimp, or else you'll have a huge leak once everything is put back together..

PS - I reused my factory hose for about 6 months after replacing this part, until I swapped my turbos, then I upgraded all my coolant and oil lines, and I had no issues for those 6 months, just make sure everything is nice and snug.. And to test your theory, top off ur coolant reservoir and start your car.. Point a flashlight in the direction of this item under the OFH, and you'll most likely see little drips coming out of it.. That's what mine did, and it actually leaked down right to the water pump area, which is what I initially thought it was that was causing the leak.. Luckily this cheap little item fixed my leaking woes.. Good luck..!

[ahhllen]

Originally Posted by BeastMode335i

That's exactly what I thought it was going to end up being, and had already planned on linking you to that item on eBay.. It's a very common failure point on these motors, and many people, myself included, have bought that eBay part to fix this issue.. You can get to it without removing much of that stuff up there, it's just a tight squeeze.. And be careful when removing it, because if it did like mine and started to disintegrate, some of those pieces can actually fall down into the engine and you'll have to flush it all out, which is not fun.. Probably a good time to do a coolant flush anyways, supposing you haven't done one recently..

Also, make sure when seating the new part that the o-ring doesn't crimp, or else you'll have a huge leak once everything is put back together..

PS - I reused my factory hose for about 6 months after replacing this part, until I swapped my turbos, then I upgraded all my coolant and oil lines, and I had no issues for those 6 months, just make sure everything is nice and snug.. And to test your theory, top off ur coolant reservoir and start your car.. Point a flashlight in the direction of this item under the OFH, and you'll most likely see little drips coming out of it.. That's what mine did, and it actually leaked down right to the water pump area, which is what I initially thought it was that was causing the leak.. Luckily this cheap little item fixed my leaking woes.. Good luck..!

I'll probably wait to do my coolant when I of my OFHG sometime this year. Would it be really messy if I don't drain the coolant when I disconnect the hose? I already ordered the eBay part and should be delivered next week. Now I just gotta figure out if I should keep driving it to work and keep refilling it for the mean time or get a rental. Thanks for the feedback, I really appreciate it!

[BeastMode335i]

Originally Posted by ahhllen

I'll probably wait to do my coolant when I of my OFHG sometime this year. Would it be really messy if I don't drain the coolant when I disconnect the hose? I already ordered the eBay part and should be delivered next week. Now I just gotta figure out if I should keep driving it to work and keep refilling it for the mean time or get a rental. Thanks for the feedback, I really appreciate it!

It's messy even when you do drain the coolant and oil lol, so you may want to consider just changing fluids when you change the parts, that's how I have typically done it and never had an issue in doing such..

[ahhllen]

Originally Posted by BeastMode335i

It's messy even when you do drain the coolant and oil lol, so you may want to consider just changing fluids when you change the parts, that's how I have typically done it and never had an issue in doing such..

Do you know how much torque is needed to tighten the 2 bolts?

[BeastMode335i]

Originally Posted by ahhllen

Do you know how much torque is needed to tighten the 2 bolts?

Honestly I just went hand tight and than about another 1/4 turn.. Just make sure the o-ring don't get crimped when installing the new one..