Coolant leak without warning

[kaput]

So my new to me X5 has a leak. Im gonna try and find it tomorrow during the day in hopes I can fix it quick. I was updating my GPS maps with the vehicle running (It's 22 degrees here so temp is not an issue) and I noticed a bit of steam. I popped the hood and sure enough, it's wet under there.

I can't tell exactly where it is coming from, but it is on the drivers side. I looked and it's possible the rad has a leak, but nothing was spewing out. The upper hose was wet, but so was the expansion tank, as was the side of the engine, but not dripping if you know what I mean. I checked the level, and it was low, below the min mark, but iDrive didn't say anything.

What are the common places you would develop a leak in a 35i X5 from 2012? I had an E46 before and it was radiator, expansion tank, blah blah, blah, but I figured some of you might know something is more likely than others. It's dark outside, so I couldn't get a great look at anything.

I'm going back to where I bought it (he also services them) since it is less than 90 days and under 2k miles to see if he can help me figure it out.

Any insight?

[AlphaBetaX5]

Originally Posted by kaput

So my new to me X5 has a leak. Im gonna try and find it tomorrow during the day in hopes I can fix it quick. I was updating my GPS maps with the vehicle running (It's 22 degrees here so temp is not an issue) and I noticed a bit of steam. I popped the hood and sure enough, it's wet under there.

I can't tell exactly where it is coming from, but it is on the drivers side. I looked and it's possible the rad has a leak, but nothing was spewing out. The upper hose was wet, but so was the expansion tank, as was the side of the engine, but not dripping if you know what I mean. I checked the level, and it was low, below the min mark, but iDrive didn't say anything.

What are the common places you would develop a leak in a 35i X5 from 2012? I had an E46 before and it was radiator, expansion tank, blah blah, blah, but I figured some of you might know something is more likely than others. It's dark outside, so I couldn't get a great look at anything.

I'm going back to where I bought it (he also services them) since it is less than 90 days and under 2k miles to see if he can help me figure it out.

Any insight?

Expansion tank cracks and leads to low coolant. Pretty common in X5s.

Happened to me!
Look for a crack and a possibly a jet stream of the coolant when engine gets to normal temperature.


The connections of the tank are also known to leak.

To change the tank: extract the coolant or drain it, then change the tank. Don’t forget to vent the system.

Search for bmw cooling system bleeding venting procedure.



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[kaput]

I know about the venting procedure. The X5 is my 4th BMW. I just wanted to know if anything specific and unique about the X5s made them get leaks.

[andrewwynn]

I just my coolant reservoir (expansion tank). It had an invisible crack that weeped fluid until it ran down the side and eventually puddled under the car. I actually noticed the cabin heat was taking longer than usual before I noticed any other symptoms.

If you replace, realize their is a thermostat for the transmission cooler if you have auto that will need to be replaced. My reservoir came with one.


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[kaput]

Can you conform that the E70 has the same thermostat for the trans cooler as an E53, as there are no manual E70s in the world?

[kaput]

Well, so far so good. Replaced the entire tank, from BMW. $130 which I didn't think was bad with all sensors and new o-rings. Just topped it off with coolant, drove it up to temp (using the scan gauge 2) and checked the level.

Seems to be doing ok. I'll report back after going to work tonight if anything happens.

[kaput]

Things seem ok. The tank was replaced and I drove it twice (once through the snow on the way home) and all is well. I assumed it would be easy. Thanks for the help AlphaBeta. It's not that I am ignorant, or blind, it was just cold as hell, and dark. I figured someone would confirm a few things to look at, and the next day (yesterday) I saw a puddle form under the upper hose connection. Replaced it and it is as good as new.

[Bimmer360]

I replaced mine too last month. Pretty common I heard for X5. Yes no warning on the iDrive either.

[andrewwynn]

I've read that the failure of the thermost in the base of the reservoir can cause the failure of the reservoir.

When I replaced mine recently, I didn't realize the kit contained the thermostat so I ended up with a spare.

I'm going to put that thermostat into my wife's x5 to see if I can't extend the life of her reservoir.


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[Tomaz]

I have replaced 2 expansion tanks in my 01' X5 4.4 with over 200K and most recently 1 tank in my 13' X5 3.5i. It appears to be an X5 common problem. At least they got rid of the incredibly fragile pipe that connects the expansion tank to the radiator on the E53