[x3Prancer]

On my 2019 30i, there is a leak on the radiator connector (the y-shaped one). I cleaned it yesterday, and this morning found some residue on the connector where the 2 lines split out from the connector. Looks like something cracked on the plastic, and now it is slowly leaking. Slowly leaking, as I topped the coolant off about a month ago, and that was the first time I topped it off since getting it in 2019. Could be getting bigger, but will see. My question is, can I do this myself? Do I need to empty the coolant, or is it easy enough to remove the hoses, disconnect the y shaped connector from the radiator, install a new one, and top it off. This seems to be a common issue, anyone hear if BMW is going to do anything about it?

You can see the coolant residue (the white stuff) forming where the lines split.

[smaglik]

I'm not familiar with where that exactly is, but if you're at a high point in the system, you may be able to get by without draining coolant. If it's not at a high point, you can use a turkey baster to pull everything you can out of the reservoir, and that'll help reduce head in the system, but tbh, draining the coolant isn't the end of the world, especially when it'll save hundreds and hundreds of $. Catch what falls out, run it through a paint strainer on the way back in to grab any particulates it might have picked up, top off, and follow the bleed procedure. I haven't had to do it on this vehicle yet, but typically you just pull off the belly pan and the blue radiator plug is right there.

[x3Prancer]

Its the one circled below. I guess my question is though, instead of having to replace the hthe entire assembly (hoses, and connector) is it possible to disconnect the hoses from the connector, then remove/replace the connector from the radiator, then re-attach the hoses? That way I wont have to mess with trying to replace the hoses too, that would make this job alot easier wouldn't it?
Thanks

[smaglik]

Originally Posted by x3Prancer

Its the one circled below. I guess my question is though, instead of having to replace the hthe entire assembly (hoses, and connector) is it possible to disconnect the hoses from the connector, then remove/replace the connector from the radiator, then re-attach the hoses? That way I wont have to mess with trying to replace the hoses too, that would make this job alot easier wouldn't it?
Thanks

No. I don't think they even sell the connector without the hoses attached. It's actually really easy to replace the connectors with the hoses attached. You just need a pick to release the connector.

[mct128i]

Originally Posted by x3Prancer

Its the one circled below. I guess my question is though, instead of having to replace the hthe entire assembly (hoses, and connector) is it possible to disconnect the hoses from the connector, then remove/replace the connector from the radiator, then re-attach the hoses? That way I wont have to mess with trying to replace the hoses too, that would make this job a lot easier wouldn't it?
Thanks

I agree completely that the problem is the molded plastic fitting - the sharp angle created where the small hose is T'eed off should have been designed with more support/webbing to help prevent this part from cracking.

While creative, your proposed solution to replace just the plastic fitting is likely more work than just replacing the entire hose. As has been stated, you can't buy just the fitting so would need to buy a new hose assembly then cut off and discard the new hose to get you just the plastic part that is leaking. Removing the metal band clamp from your existing hose could be done but would require care in order to not damage the rubber.

I recently replaced the hose assembly (along with replacing the plastic connector pipe that mates to the cylinder block) and it's doable by the average home mechanic. The connector pipe replacement is not at all necessary (unless it's also leaking) and omitting this step would make the job much easier.

[x3Prancer]

ok, thanks mct128i......yea that clamp is permanently attached and would need to get cut off...I was thinking dremel....then a new clamp would be needed to connect the old hose back on....risky I agree. Still thinking about it....maybe removing the computer out of the way is easier.... Did you lose alot of coolant the way you did it? How did you top it off, did you have to do the vacuum fill, or did you just top it off in the fill tank?

[mct128i]

Originally Posted by x3Prancer

ok, thanks mct128i......yea that clamp is permanently attached and would need to get cut off...I was thinking dremel....then a new clamp would be needed to connect the old hose back on....risky I agree. Still thinking about it....maybe removing the computer out of the way is easier.... Did you lose alot of coolant the way you did it? How did you top it off, did you have to do the vacuum fill, or did you just top it off in the fill tank?

I don't recall how much fluid I needed when refilling but I purchased 1 gallon (which makes 2 gallon once mixed with deionized water) from the dealer along with the hose. It's hard not to make a mess - I simply disconnected the hose from the radiator and drained as much as I could into a narrow container I placed at the front of the engine, angling the hose down gets most of what you need out. Be sure to purchase the correct coolant - early 2019's use the blue and later ones use the green coolant.

Once hose replacement is complete, fill via the expansion tank and then follow the coolant bleed procedure which takes around 11 minutes. Search on here for this if you don't have this procedure.

[abbike18]

Hi everyone - had a coolant issue myself just recently. Had a really slow leak. Went searching through the engine bay and found no evidence of a leak. Read around and decided to try the expansion cap.

No luck. Still a slow leak. Then (see first picture) I discovered white crust under the forward tube on the expansion tank. During a pressure test this bit would even leak if I jiggled it. This also made sense since it would only be gasses escaping here - so slow and no evidence. Must have found it! Replaced the front tube.

Did a pressure test and no luck - still losing pressure. Not sure, I left the car sit overnight. Came back the next morning to try a pressure test again and when I pressurized it I heard a slow drip. I went investigating and was able to trace down the turbo coolant hoses where they enter the turbo. It was the top hose. See second picture.

This all made sense now - The system only leaks when it has pressure. It only has pressure when it is hot, and the turbo is hot. So any leaking coolant would get vaporized instantly and leave very little evidence.

I pulled the tube and replaced the O-rings for $6 each. Here's the scary thing though - the o-rings are only 14 months and 14k miles old! They were in a very compressed flat shape. The new o-rings were 1.5mm thick and the ones I pulled out were compressed down to 1.25mm. So I'm a bit confused here why they would go bad so fast - Maybe a fluke or maybe there's some issue with the o-rings. See the last picture for a visual of old (barely) vs new oring.

[Novvaa]

Can someone who has performed the bleed procedure describe it here? Do I need any special tools or anything?

[freshxdough]

Originally Posted by abbike18

Hi everyone - had a coolant issue myself just recently. Had a really slow leak. Went searching through the engine bay and found no evidence of a leak. Read around and decided to try the expansion cap.

No luck. Still a slow leak. Then (see first picture) I discovered white crust under the forward tube on the expansion tank. During a pressure test this bit would even leak if I jiggled it. This also made sense since it would only be gasses escaping here - so slow and no evidence. Must have found it! Replaced the front tube.

Did a pressure test and no luck - still losing pressure. Not sure, I left the car sit overnight. Came back the next morning to try a pressure test again and when I pressurized it I heard a slow drip. I went investigating and was able to trace down the turbo coolant hoses where they enter the turbo. It was the top hose. See second picture.

This all made sense now - The system only leaks when it has pressure. It only has pressure when it is hot, and the turbo is hot. So any leaking coolant would get vaporized instantly and leave very little evidence.

I pulled the tube and replaced the O-rings for $6 each. Here's the scary thing though - the o-rings are only 14 months and 14k miles old! They were in a very compressed flat shape. The new o-rings were 1.5mm thick and the ones I pulled out were compressed down to 1.25mm. So I'm a bit confused here why they would go bad so fast - Maybe a fluke or maybe there's some issue with the o-rings. See the last picture for a visual of old (barely) vs new oring.

If the car is only 14 months old then why not let warrant take car of it

[abbike18]

Originally Posted by freshxdough

If the car is only 14 months old then why not let warrant take car of it

Car was out of warranty. orings were from a turbo install

[x3Prancer]

So, as seen from my previous post in the thread, the upper radiator hose connector had a leak in the area where the auxiliary host connects to it. The auxilliary hose leads to the heater core. This seems to be a common failure point. There were no other leaks that I could find. Instead of replacing the entire coolant hose, I opted to replace only the plastic connector. In order to do this, I had to purchase the entire hose, and cut off the clamp, and remove the hose from the connector. When I started to remove the auxilliary hose from the side of the main upper radiator hose connector, I couldn't. It was fused so badly I couldnt get them separated. It ended upbreaking off. Once I got the side piece off, I removed the main connector from the radiator, which wasn't so bad, just required some gentle tugging. After the connector was separated, i cut the clamp off of the main upper radiator hose, and separated the hose from the connector. Then I put the new connector in (I put a little vaseline to make it go in easier), then connected the uper radiator hose and the auxilliary hose to the connector using Koehler screw clamps. To access that area a little better, I removed the screw nearest the front of the car from the silver crash brace, and pushed that off to the side.

I had very little coolant loss. Maybe 1/2 - 3/4 of a jug, most of which was loss of coolant due to the leak from before. The resevoir was filled 3/4 of the way, and Im monioring it for a few days if it needs to get topped off.

Also one important thing I realized. Because the auxilliary hose got fused to the upper hose connector, I would have had to replace BOTH hoses completely, that would have made this job considerably more work if I replace the entire the hoses instead of just the connectors.

So far so good, the job took me in total about an hour.

Here are the parts I needed to buy:

Radiator Hoses:
64-21-9-354-459 (heater core hose for 2019 X3 sDrive)
17-12-7-535-529 (upper radiator hose for 2019 X3 sDrive)
Clamps:
Koehler Enterprises Hose Clamps, Hose Clamp Box of 10, Radiator Hose Clamp, Silver, Size SAE 20
Koehler Enterprises Hose Clamps, Hose Clamp Box of 10, Radiator Hose Clamp, Silver, Size SAE 28
BMW Coolant
Distilled water

You will need a dremel to cut the existing clamps off, a screwdriver, and pliers

Here are some pics.

[tjswarbrick]

Just confirming that "some things never change."

Wife's 2018 X3M40i started leaking coolant last week, at 62k miles.
Dealer diagnosed upper radiator hose. Wants $1060 to replace. Hoses not covered under CPO warranty.
Since since they're in there, he recommends lower radiator hose at the same time. Additional $200, parts and labor (labor is minimal with upper hose off and system drained.)
He said it's like 4.2 hours (book) labor for the upper hose.
I mainly came on here to see if he's completely off his rocker. Looks like he isn't, so I'll have him fix it. Begrudgingly. And do the lower one so I don't have to come back in 5000 miles for that.
Urgh.
On the bright side, it's the first repair I've had to pay for on this car since we bought it in 2020 with 18k mi on the odo.
(I also have a 150,000 mile non-CPO 135i, so I know that's bound to change...)

[runwild]

Can you guys help me to figure out if I have a leaking hose or it’s my radiator? I found my leak just now… it looked wet near the lower hose where it connects to the radiator.

I also have a 2019 and just hit 65k miles. So ironic how these problems seem to be happening at the same year/mileage range

[tjswarbrick]

Originally Posted by tjswarbrick

Just confirming that "some things never change."

Wife's 2018 X3M40i started leaking coolant last week, at 62k miles.
Dealer diagnosed upper radiator hose. Wants $1060 to replace. Hoses not covered under CPO warranty.
Since since they're in there, he recommends lower radiator hose at the same time. Additional $200, parts and labor (labor is minimal with upper hose off and system drained.)
He said it's like 4.2 hours (book) labor for the upper hose.
I mainly came on here to see if he's completely off his rocker. Looks like he isn't, so I'll have him fix it. Begrudgingly. And do the lower one so I don't have to come back in 5000 miles for that.
Urgh.
On the bright side, it's the first repair I've had to pay for on this car since we bought it in 2020 with 18k mi on the odo.
(I also have a 150,000 mile non-CPO 135i, so I know that's bound to change...)

Finally got the X3 back. Dealer charged $1,302 labor PLUS $444 parts. He gave my wife a $150 discount when she called him on it. $1633 total, vs the $1400 he told me.