What pressure for radiator 328i

Grease23 · 05-09-2024, 08:27 PM

I changed the thermostat and the coolant and the upper radiator hose. Poured in new coolant. Then before I ran the bleeding procedure, I thought I'd pressure test the coolant system. Everything is great until I hit 6 psi, at which point the radiator end of the new coolant hose moves back slightly and coolant sprays and pours out. The clip is still in place.

Am I expecting too much of these goofy clip-on hose connections? I'm used to cars passing easily at 10 to 12 pounds. The upper hose is from fcp but I don't think it is BMW official product. I'm hoping somebody is going to tell me that these are special low pressure systems and 5 psi or so is fine, but I realize that would be too good to be true.

Thanks for your help.

Grease23 · 05-10-2024, 08:17 AM

Turns out the problem is the after-market hose. (Vaico brand?) It slides on, but just won't slide on the last 1/16th inch that the factory one does. Since the channel for the metal clip is quite narrow, this prevents the clip from engaging. I've tried pushing as hard as I can and it won't quite get there. I'm going to go get the factory hose from a dealer today.

What is a bit surprising in retrospect is that the cooling system will hold 5-6 psi with no clip engaged. It doesn't leak at all, then it suddenly pops off with a real gusher.

05-09-2024, 08:27 PM	#1
Grease23 Enlisted Member 33 Rep 36 Posts Drives: BMW 328i Join Date: Jan 2024 Location: Seattle iTrader: (0)	What pressure for radiator 328i I changed the thermostat and the coolant and the upper radiator hose. Poured in new coolant. Then before I ran the bleeding procedure, I thought I'd pressure test the coolant system. Everything is great until I hit 6 psi, at which point the radiator end of the new coolant hose moves back slightly and coolant sprays and pours out. The clip is still in place. Am I expecting too much of these goofy clip-on hose connections? I'm used to cars passing easily at 10 to 12 pounds. The upper hose is from fcp but I don't think it is BMW official product. I'm hoping somebody is going to tell me that these are special low pressure systems and 5 psi or so is fine, but I realize that would be too good to be true. Thanks for your help.
	Appreciate 0 Tweet Quote

05-10-2024, 08:17 AM	#2
Grease23 Enlisted Member 33 Rep 36 Posts Drives: BMW 328i Join Date: Jan 2024 Location: Seattle iTrader: (0)	Turns out the problem is the after-market hose. (Vaico brand?) It slides on, but just won't slide on the last 1/16th inch that the factory one does. Since the channel for the metal clip is quite narrow, this prevents the clip from engaging. I've tried pushing as hard as I can and it won't quite get there. I'm going to go get the factory hose from a dealer today. What is a bit surprising in retrospect is that the cooling system will hold 5-6 psi with no clip engaged. It doesn't leak at all, then it suddenly pops off with a real gusher.
	Appreciate 0 Quote