x3Prancer wrote

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.

abbike18 wrote

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.

runwild wrote

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

805jive wrote

Abbike, did the o-rings work to fix the leak on the opaque reservoir hose or did you have to replace the whole hose? I have the same problem. Can you send a link to the o-rings you used? How do you disconnect that little hose from the reservoir? All these connections look like brittle plastic and I don't want to break anything. Let me know when you have a moment. Thanks.

x3Prancer wrote

Another leak found on the turbo coolant line. These things are a cheap piece of crap. The hose looks short, it connects to the metal line attached to the turbo.

mamboX3 wrote

My 2 cents. I did this as well this weekend. I ordered the hose, took the plastic T out of it. Dremel the ring off of the original hose. Reinstall the new plastic T with a hose clamp and reattached everything. The only difference I did vs you, is that I created a cork plug as to not loose too much coolant from the radiator. Lost about 1/4 of the reservoir just from the unplugging of the hose.

x3Prancer wrote

I completed the repair of the turbo coolant line. It was really easy. The hardest part was getting my screwdriver to find the tab of the top plastic connector to pop it up so I could remove it. Total cost of parts for this was $21 USD.

One important thing I found out was, the leak wasn't actually the plastic connector. That piece was fine upon inspection when I removed it. The reason for the leak was clamp. The clamp is another cheap, POC, that wasnt holding the coolant from seeping thru. If you want, you could just replace the clamp for $1 with a better one. BMW obviously wanted to save 50 cents and get the shops to take away our $900 (that was the quote I got to replace this coolant line).


2019 X3 sDrive:
Coolant Hose: https://www.ebay.com/itm/355751929771
Part #: 11 53 8854735
Clamps: Autozone EZ clamp 1/4" (made by Koehler)

x3Prancer wrote

When you cut the top off the clamp where you have drawn, the clamp will pop and loosen up. From there, you can use a flat head screwdriver to remove it. Very easy to do. I was thinking of putting 2 clamps in there as well, but decided not to. You could try replacing only the clamp first, and see if that fixes your leak. If not, then replace the connector too. The hardest part of this job for me was finding the clip of the connector to pop it up. Its facing away from you towards the engine, so its not easy to see it.

805jive wrote

Did you find that your leak came from the upper radiator hose tee connection or was it lower down on the ribbed plastic tube that goes down the driver side of the radiator?

runwild wrote

Mine was from the t-fitting but I bought it with the upper hose from BMW and found an Indy shop that replaced it for a few hundred bucks. It’s been good ever since

805jive wrote

Okay, good to know because the leak appears to be coming from an area below the t-fitting. Your photos were very similar to mine. Thanks for the update.

805jive wrote

Okay, good to know because the leak appears to be coming from an area below the t-fitting. Your photos were very similar to mine. Thanks for the update.

Jolbex wrote

Just a quick question: why do you cut this clamps? Its the easiest clamp to open, just use a flat screwdrive, push under the "locking ridge' and pop it open. Its a 1 second job.