[A14]

2021 x3 xdrive30i w/ B48, 105k kms (65.5k miles): Twice now the white coolant tank has been low on coolant, the first time it showed a dash light, second was just low in the tank. I found traces of dried coolant coming from the oil filter housing. Drained oil and it’s good, no evidence of mixing.

I’m going to order the metal oil filter housing but what else should I be preemptively changing? Water neck? Which lines are particularly prone to failure or should they just all be done? Any other upgrades available besides the filter housing?

Trying to keep it reliable… (perhaps a futile goal?) If I’m going to end up slowly piecemeal replacing a bunch of stuff I’d sooner just do it all at once and save a roadside failure. Thanks

[admranger]

FCP Euro has a video on replacing the oil filter housing on a B58 iirc, which should be similar to the B48. They mention some preemptive maintenance items to change iirc.

[tig488]

i got the aluminum neck and housing, I also changed the large T pieced pipe that runs to the neck. also replace the Rein gaskets with OEM BMW ones. I read where the Reins leak after a few months.

[X3dr1ver]

Rein is one of the many BMW OEM suppliers so there's a big chance you're buying the same thing for more money.

[Mondomensch]

There have been reports of leaks when using the gaskets that come with the aluminum OFH and not swapping in BMW ones.

[bje3524]

Also regarding the neck, don’t purchase the aluminum neck Rein neck (CRP-CHU0929) because the packing that comes with the neck will fail early (Read the reviews on FCP Euro). Replace the neck with the original plastic BMW one (11118511205) that has the good OEM packing. My Rein neck packing failed soon after the replacement.
And as stated above by Tig488 for the aluminum OFH, instead of the Rein packings use BMW OFH packings 11428591460.

[srybicki]

I just had my done on my 530e at 140k miles. Used OEM also changed the water pump and thermostat since we were in there already.

[Bergan00]

Originally Posted by A14

2021 x3 xdrive30i w/ B48, 105k kms (65.5k miles): Twice now the white coolant tank has been low on coolant, the first time it showed a dash light, second was just low in the tank. I found traces of dried coolant coming from the oil filter housing. Drained oil and it’s good, no evidence of mixing.

I’m going to order the metal oil filter housing but what else should I be preemptively changing? Water neck? Which lines are particularly prone to failure or should they just all be done? Any other upgrades available besides the filter housing?

Trying to keep it reliable… (perhaps a futile goal?) If I’m going to end up slowly piecemeal replacing a bunch of stuff I’d sooner just do it all at once and save a roadside failure. Thanks

So i just went through this entire process myself and one thing I learned is there are 2 different cooling systems, old and new 2020 up uses the new so you dont have the gooseneck and the oil filter housing is a 5 bolt housing instead of a 4 bolt, what went on mine was the coolant line from the expansion tank to the block, had to remove the intake manifold for that. I also upgraded to a aluminum oil filter housing and changed the Heat Managment module

[tig488]

what I did was purchase the OEM plastic water neck from BWM AND the Rein, (the plastic was less than $40) and used the OEM BMW gasket with the Rein neck. I dont think you can buy just the OEM neck gasket by itself. I just felt more comfortable having the aluminum neck because the plastic is what cracked. i didnt mind buying the oem neck just for the gasket.

[Bergan00]

Originally Posted by tig488

what I did was purchase the OEM plastic water neck from BWM AND the Rein, (the plastic was less than $40) and used the OEM BMW gasket with the Rein neck. I dont think you can buy just the OEM neck gasket by itself. I just felt more comfortable having the aluminum neck because the plastic is what cracked. i didnt mind buying the oem neck just for the gasket.

I did the same on the new cooling system there is no coolant hose that goes into the oil filter housing but I swapped the gasket that was on there with an OEM gasket costed around 30 bucks but was worth it

[mct128i]

Originally Posted by tig488

what I did was purchase the OEM plastic water neck from BWM AND the Rein, (the plastic was less than $40) and used the OEM BMW gasket with the Rein neck. I dont think you can buy just the OEM neck gasket by itself. I just felt more comfortable having the aluminum neck because the plastic is what cracked. i didnt mind buying the oem neck just for the gasket.

Just curious - were there any obvious differences between the two gaskets?

[tig488]

No they looked and felt identical but there has to be a difference because people were saying after a month or so the reins started leaking again. So their material must be more affected by heat cycles than the bmw ones.

[chrisk03]

My Indy did the aluminum OFH, BMW gaskets, water pump, and some other hoses from water pump...around 80k miles on our B48. Make sure to follow the bleed/purge procedure for air in the lines after all put back together or you'll likely have low coolant in 1 or both coolant tanks (clear/black).

[mperl93]

I have a leak in my heat management module and at the same time I am planning to change the oil filter housing to aluminum. I only found it available through OEMBimmerparts.com, they sell Hudson and RhineWerks for the 2021 X3 B48 engine. My plan based on research was to use BMW gaskets between the housing and block. For the oil cooler to the housing I can't find BWM gaskets, has anyone had an issue with the aftermarket aluminum housing oil cooler to oil filter housing gaskets leaking on the TU version OFH?

[Wgosma]

Be careful about the housing- was at my local independent BMW shop and they had multiple problems with aluminum OFH and related parts for cooling system, they indicated leakage and have reverted to using Genuine BMW plastic housings.

[Mondomensch]

At least the new plastic bmw ones should be good for another 60k miles, which might be enough for your ownership.

[smass]

This thread reminded me I need to come up with a preemptive plan for my original cooling system that has 125k miles on it. I checked FCP and ECS and the pricing seems to have jumped up 25% in the past few weeks. This was for my B58. Hopefully this is just temporary.

[evox]

Originally Posted by smass

This thread reminded me I need to come up with a preemptive plan for my original cooling system that has 125k miles on it. I checked FCP and ECS and the pricing seems to have jumped up 25% in the past few weeks. This was for my B58. Hopefully this is just temporary.

The B58 has a much different oil filter housing design than the B48; it doesn't suffer the same problem as the unit on the B48s. It's still made of the same thermoplastic manufactured by Mahle, but because of the way the coolant and oil passages are laid out it doesn't fail like on the B48s.

On the B48s 9 times out 10 it's the center squarish coolant passage that fails. It's a bad design.

I just did the one on my daughter's X3's B48. It failed at 70,074 miles. When I replaced her oil filter housing she also saw weeping from two other coolant lines. The turbo coolant return line, and the heater core return line. But there were a number of lines that the thermoplastic of the quick connects were showing evidence of browning degradation but weren't leaking, so I went ahead and replaced all her coolant lines. Which was a little overkill.

I fully expect to be replacing other components on her B48's coolant system before she has 125k miles on it.

For B48 owners I'd put this on the list of preventative maintenance BEFORE 70k miles or you to might experience the joys of paying for a flatbed tow.

[evox]

Originally Posted by A14

2021 x3 xdrive30i w/ B48, 105k kms (65.5k miles): Twice now the white coolant tank has been low on coolant, the first time it showed a dash light, second was just low in the tank. I found traces of dried coolant coming from the oil filter housing. Drained oil and it’s good, no evidence of mixing.

I’m going to order the metal oil filter housing but what else should I be preemptively changing? Water neck? Which lines are particularly prone to failure or should they just all be done? Any other upgrades available besides the filter housing?

Trying to keep it reliable… (perhaps a futile goal?) If I’m going to end up slowly piecemeal replacing a bunch of stuff I’d sooner just do it all at once and save a roadside failure. Thanks

Every owner with B48 engine should probably plan on doing this (if it already hasn't been done) between 50k-70k mile. The thermoplastic oil filter housing is a bad design. 9 out of 10 will have their center (squarish) coolant passage fail. There is a lawsuit filed on this, and I suspect BMW will be required to do at least one recall. But the way the the passages on the B48 sit I don't know what they're going to do other than replace it with an aluminum housing.

So yes, on the B48 I think it's a good idea to go ahead and replace the oil filter housing BEFORE it fails. I just did this on my youngest daughters 2019 X3. It failed right at 70,074 miles requiring a tow home.

She also had weeping from the turbo coolant return hose right at the auxiliary water pump, and she had weeping at the heater core coolant return hose right at the junction on engine coolant return line. I replaced all the hoses in the coolant system. Which was overkill.

If you don't want to go through the expense of doing what I did at least while you're doing the oil filter housing you might consider visually inspecting all the quick connects for signs of degradation or weeping (turning brown or discolored--dried coolant evident) and I'd replace any I found. Pay special attention to the thermoplastic junction between the engine coolant return hose and the heater core return hose, it has been known to crack at that junction.

With the clearance you'll have while doing the oil filter hosing you'll have the best access to the heater core coolant hoses which run from the firewall down long the left side of the bay under some coolant lines and DME, so you might want to go ahead and replace both of those. I'd also plan on replacing the short coolant hose running from the oil filter housing to the transmission heat exchanger. You'll have to disconnect that hose to replace the oil filter hosing and the O-rings often kind of form fit to their old connection point, so once disturbed they can leak. I'd also replace the engine coolant flange, leaking or not at over 60k miles while you are there, and I'd replace the engine coolant return line (the one with the junction with the heater core return line). Oh and you probably want to replace the Engine Coolant Overflow Hose, if it's not already cracked there's a good chance you crack and or break it during this procedure.

I removed the intake manifold and DME, some people just remove the intake, and some have said they can do it by just removing the DME, I did both. So I had wide open access on that side of the engine bay. Since it was my youngest daughters car I went a little overboard.

Some people go further and just plan for a total refresh of the coolant system. Heat management unit, Water pump, idler pully, 2 auxiliary water pumps, and radiators.

If you chose to do all that using BMW or OEM parts that could run up your bill. Just spitballing The heat management unit is around $500, waterpump(s) all in probably $800-$1,000, and radiators...I'd have to price it, around $1,000 I imagine.

Mahle makes the heat management units for BMW, so you can get the exact same heat management unit without the BMW logo and box for a couple of hundred less. I think Rein makes the coolant hoses, so you could also save some money there.

Still, to refresh the entire coolant system to showroom new, you're probably looking at $3k doing it yourself, and your first born child if the dealership did it for you (jokes).

[smass]

Originally Posted by evox

The B58 has a much different oil filter housing design than the B48; it doesn't suffer the same problem as the unit on the B48s. It's still made of the same thermoplastic manufactured by Mahle, but because of the way the coolant and oil passages are laid out it doesn't fail like on the B48s.

On the B48s 9 times out 10 it's the center squarish coolant passage that fails. It's a bad design.

I just did the one on my daughter's X3's B48. It failed at 70,074 miles. When I replaced her oil filter housing she also saw weeping from two other coolant lines. The turbo coolant return line, and the heater core return line. But there were a number of lines that the thermoplastic of the quick connects were showing evidence of browning degradation but weren't leaking, so I went ahead and replaced all her coolant lines. Which was a little overkill.

I fully expect to be replacing other components on her B48's coolant system before she has 125k miles on it.

For B48 owners I'd put this on the list of preventative maintenance BEFORE 70k miles or you to might experience the joys of paying for a flatbed tow.

Good to know about the B58 OFH. I finally found my seepage. It the fitting on the OFH for the hose that goes up to the electric pump. I may just change the O ring as I think I can reach it from underneath. I also have a seeping water pump, $500+ and only available from BMW......

If this were my daughter's car I would change 100% of the cooling system right now. $3k+ in parts alone! We live in AZ so this is a safety issue. But since it is mine, I carry water around and can limp it home in most situations.

[Wgosma]

Coolant system refresh at 50K miles, no way…70K maybe. The independent BMW shop who works on my car when I can’t or won’t suggested 100K based on their experience, and yes they have done quite a few OFH replacements.

[evox]

Originally Posted by smass

Good to know about the B58 OFH. I finally found my seepage. It the fitting on the OFH for the hose that goes up to the electric pump. I may just change the O ring as I think I can reach it from underneath. I also have a seeping water pump, $500+ and only available from BMW......

If this were my daughter's car I would change 100% of the cooling system right now. $3k+ in parts alone! We live in AZ so this is a safety issue. But since it is mine, I carry water around and can limp it home in most situations.

For B48 owners when the OFH goes it can go really fast with little or no warning. What you think might think is a slow leak from O-rings leaking will turn into a pull over right now and shut her down event.

My daughter said her low coolant level warning came on at a stop light, and almost immediately upon driving forward she got an engine overheating warning.

Thankfully I taught her well, she pulled over immediately, so no turbo damage. The coolant hemorrhaged out fast from the low side, she called me, I was pretty sure what it was, I got there confirmed it the low side was almost completely drained, and called a flatbed tow truck. There was no limping home on this one.

I was angry at myself because I knew the problem with the B48's thermoplastic OFH, and was planning to change hers out preemptively, but put it off. Like I said B48 owners really need to do this before theirs fail. Hers failed at just over 70k miles, but some have bit the dust as early as 30k-40k miles.