Turning heater on exploded my cooling system

[Fried_Chicken]

I pulled the two hoses going to the heater core off because I suspected the leak would be around there. No leak there.

However, when I looked, the hose running sort of perpendicular underneath had completely come off from wherever it’s supposed to be attached. For the life of me I can’t figure out where that hose goes. It goes from the front, along the driver’s side of the engine, then turns left towards the passenger side and into the engine or something.

What hose is this? Can I reach it without taking the intake manifold off?

[edit]

Found the connector, hopefully I can reach it w/o taking off the intake manifold:

37406

[Vas]

There are 2 hard plastic coolant lines under the intake manifold that eventually fail and leak. Unfortunately the intake manifold has to be removed to access them.

Image below is showing the cooling system hoses. https://uploads.tapatalk-cdn.com/20201027/605064f917390c7768237fd0ba8c059b.jpg

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[Fried_Chicken]

That pic is perfect ^ ^

Just got some clarity: The hose that broke is: 64218376999 or 64218376153. I’m not sure which one.

Specifically the connector at the end broke so the hose is floppy. If I can remove it by hand (I can reach it by hand), I could replace the hose without having to take the intake manifold off. I plan on reworking the entire cooling system, but now is inconvenient for me. Was planning on doing that in ~30k miles. I see form the pic I could conceivably reach the clip. If I can pull the clip off, I should be golden.

Is there any particular brand that isn’t prone becoming brittle and breaking like the OEM hoses are?

[Vas]

That pic is perfect ^ ^

Just got some clarity: The hose that broke is: 64218376999 or 64218376153. I’m not sure which one.

Specifically the connector at the end broke so the hose is floppy. If I can remove it by hand (I can reach it by hand), I could replace the hose without having to take the intake manifold off. I plan on reworking the entire cooling system, but now is inconvenient for me. Was planning on doing that in ~30k miles. I see form the pic I could conceivably reach the clip. If I can pull the clip off, I should be golden.

Is there any particular brand that isn’t prone becoming brittle and breaking like the OEM hoses are?Part number 64218376999 is the hose that connects to the hard coolant line under the intake manifold. The other end of it uses a hose clamp and connects to the heater valve control valve.

Part number 64218376153 connects directly to the heater core on the firewall and goes to the expansion tank/bracket.

Both hoses can be replaced without removing the intake manifold.

As far as the plastic coolant lines, genuine bmw is the best option. There are other manufacturers that make them out of plastic but they don't fit/seal well to the engine.

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[Fried_Chicken]

Part number 64218376999 is the hose that connects to the hard coolant line under the intake manifold. The other end of it uses a hose clamp and connects to the heater valve control valve.

Part number 64218376153 connects directly to the heater core on the firewall and goes to the expansion tank/bracket.

Both hoses can be replaced without removing the intake manifold.

As far as the plastic coolant lines, genuine bmw is the best option. There are other manufacturers that make them out of plastic but they don't fit/seal well to the engine.

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64218376999 it is.

I already ordered the part made by Elaplast, apparently they’re German OEM. Hopefully I can get it sorted and be on my merry way. For bleeding, I turn the heater on, fan on medium, park the car on an incline, leave the expansion tank open, and keep pumping fluid until the appropriate level is reached?

[Vas]

64218376999 it is.

I already ordered the part from Elaplast, apparently they’re German OEM. Hopefully I can get it sorted and be on my merry way. For bleeding, I turn the heater on, fan on medium, park the car on an incline, leave the expansion tank open, and keep pumping fluid until the appropriate level is reached?For bleeding procedure see below,

Loosen the coolant expansion tank bleeder screw. Turn the ignition ON (do not start engine), set the temperature controls in vehicle interior to full warm and blower fan speed on low. Slowly fill the expansion tank until coolant level is at the top. Install coolant cap and start the engine. Run engine until coolant is coming out of the expansion tank bleeder screw and is free from bubbles. Once coolant is free of bubbles, tighten the expansion tank bleeder screw.

Shut the engine OFF and allow it to cool. Check the coolant level in expansion tank. Top up coolant until level indicator is at MAX. Once at MAX, your cooling system is full.*

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[Fried_Chicken]

For bleeding procedure see below,

Loosen the coolant expansion tank bleeder screw. Turn the ignition ON (do not start engine), set the temperature controls in vehicle interior to full warm and blower fan speed on low. Slowly fill the expansion tank until coolant level is at the top. Install coolant cap and start the engine. Run engine until coolant is coming out of the expansion tank bleeder screw and is free from bubbles. Once coolant is free of bubbles, tighten the expansion tank bleeder screw.

Shut the engine OFF and allow it to cool. Check the coolant level in expansion tank. Top up coolant until level indicator is at MAX. Once at MAX, your cooling system is full.*

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Clear as day. Appreciate it. It was always a wild goose chase for me to properly bleed the system.

[Fried_Chicken]

Fixed!

The old hose I had was a total PoS. Unfortunately I don’t know the company (I installed it 10 years ago or so when I did my whole cooling system).
The new is by a company called Elaplast, and it fit beautifully, and had an o-ring (unlike the unknown old one.

[johnrando]

Glad that worked out.

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[John in VA]

The old hose I had was a total PoS. Unfortunately I don’t know the company (I installed it 10 years ago or so when I did my whole cooling system).
!0 years is a good lifespan for a hose, POS or otherwise!

[Fried_Chicken]

Glad that worked out.

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Thanks! Hopefully the cooling system lasts another 30k miles, then I'll go and do everything. Now's an inconvenient time.


!0 years is a good lifespan for a hose, POS or otherwise!

Yeah, it's a PoS b/c it was a PITA to install and uninstall. It used plastic compression rather than an o-ring. I remember how awful it was at the time. The new one has an o-ring making life easy.

[Fried_Chicken]

Car is leaking... I'm just going to do the whole cooling system. I'm not going to play cat and mouse with this.

[Fried_Chicken]

Just finished the whole cooling system... 3 days straight of work, although it took a bit to get my groove on.

Removed the intake manifold, replaced the solid cooling lines, replaced the engine temperature, oil pressure, and coolant temperature sensors, water pump, radiator, expansion tank, radiator hoses and the radiator. Cleaned the throttle body and got new gaskets, as well as all the oil separator hoses. Admittedly, the intake and breather hoses were quite clean. Left the heater corse hose because it is out of RUBBER AND DOESN'T GET BRITTLE AND BREAK WHAT A CONCEPT BMW TAKE NOTE. Also did the spark plugs and coils, and I also wrapped the little electric lines w/new plastic coverings where it got brittle and turned to fuzz.

I'm still not sure how to refill/bleed the cooling system on these, but starting the engine, letting it idle, and continually topping off the expansion tank did the trick. Once it stopped sucking coolant, I topped it off, revved it, let it sink; rinse + repeat. Obviously the heater was running to get all the shit into the heater core. I also did the oil filter housing gasket, and did an oil change before starting the engine to drain any gritty shit that might have dropped into the oil system before it can cause damage somewhere. Basically repeated what I did 7 years ago. It was surreal going back in and thinking about what naïve hands did all this work the first time. I also pressure tested the system, and it held 10 psi for a solid 5 minutes.

While I had the alternator out, I checked the brushes and they're well worn. I tried two voltage regulators and neither were the right part. I have pictures, so now I'm on the hunt for the appropriate one. I don't want to buy a new alternator if I don't need to.

All in all, I've developed a newfound hatred for plastic. Plastic can die in a fire, except then it'll give you cancer. My friend has a nissan 350z, and it's held together by gum, spit, zip-ties, and gypsy magic. He also feeds it the shittiest wal-mart fluids money can buy. Even still HE doesn't have to dismantle half his engine every 7 years. Whatever, in the end he drives a nissan, while I drive a BMW.

[Will]

Nice work, glad you got that leak taken care of and those parts replaced.

Maybe you can try this place for alternator parts: Maniac Electric Motors (https://www.maniacelectricmotors.com/2001-2005-bmw-320-325-330-525-120-amp-alternator-0124515050-0124515097.html)

Disclaimer: I've never used them before, just passing along a referral.

[Fried_Chicken]

I found the appropriate voltage regulator part. $60 should keep my alternator running for another 160k miles, hopefully.

[Will]

Nice. Hope it fixes it. Keep us posted. Where'd you end up sourcing the voltage regulator from?

[Fried_Chicken]

Nice. Hope it fixes it. Keep us posted. Where'd you end up sourcing the voltage regulator from?

FCP Euro carries them. I suspect someone swapped out the connector on mine (car side), because I'd prior ordered one specific for the vehicle and it was the incorrect one.