[MadToy]

Just replaced both my water pump and thermostat on my 11 N55 335i. During the bleed procedure, the new pump was quite loud - sounding like an RC airplane taking off. Everywhere I read about it, everyone says it's very quiet. Both pump and tstat are OE parts from Bimmerparts. Did I get a bad pump?

[GoRomeo]

Originally Posted by MadToy

Just replaced both my water pump and thermostat on my 11 N55 335i. During the bleed procedure, the new pump was quite loud - sounding like an RC airplane taking off. Everywhere I read about it, everyone says it's very quiet. Both pump and tstat are OE parts from Bimmerparts. Did I get a bad pump?

Probably, Ask them to send you a new replacement pump so you can install it and re-assure that indeed is defective.

[MadToy]

That's what I'm afraid of. 3 hours of hard work completely for nothing :/

[MadToy]

Mine sounds just like this. Seems some folks think it's normal. I hope so....

[///Mposter]

Originally Posted by MadToy

Just replaced both my water pump and thermostat on my 11 N55 335i. During the bleed procedure, the new pump was quite loud - sounding like an RC airplane taking off. Everywhere I read about it, everyone says it's very quiet. Both pump and tstat are OE parts from Bimmerparts. Did I get a bad pump?

After I did my single turbo kit , I had to bleed the pump. I thought maybe I didn't fill it enough , but when I ran the bleed cycle the second time, it made the weird noise at the same sequence again . It's quiet when you start it, then you are okay. But if you warm the car up and it's making noise ( non bleed cycle) then I would assume you do have an issue.

[MadToy]

Originally Posted by ///Mposter

After I did my single turbo kit , I had to bleed the pump. I thought maybe I didn't fill it enough , but when I ran the bleed cycle the second time, it made the weird noise at the same sequence again . It's quiet when you start it, then you are okay. But if you warm the car up and it's making noise ( non bleed cycle) then I would assume you do have an issue.

I did find another video of an N55 making the same noise. I haven't started it yet, since I also changed plugs, and broke a coil - so have to wait for the new coils to get here before I can crank it up.

Thanks!

This is exactly how it sounds - even though it doesn't seem to be an issue for this guy.