Is my water pump going bad?

[HyeWarrior]

So I've come across an issue, curious what you guys may think

-2012 N55 with 55K miles
-Just installed a JB4 Harness B over the weekend with a charge pipe and intake
-Flex Fuel wires were not connected (not sure if this is a big deal)
-Car drove fine all week on Map 5, yesterday morning sitting in traffic, yellow engine overheating light comes on, then turns red by the time I pull over. I shut the car off, let it cool down, reset to Map 0. Checked engine bay, no signs of anything wrong. Turned the car on again and drove to work perfectly fine on Map 0
-Checked coolant level in the afternoon after work, coolant was basically empty, filled with water to get me home
-Car drove fine for 20 miles, but got a CEL towards the end of my drive
-Checked this morning and the water in the coolant tank is still at the same level, so I don't believe there's a leak anywhere



Forgive me for being a noob, im still new to these cars, but I'm just trying to figure out what it might be. Im going to try to read the codes tonight at some point. I'm wondering if this is a water pump issue, or something related to the charge pipe/tune...

Any ideas?

Thank you guys SO much

[HyeWarrior]

Finally was able to run some codes.

28A0
2C57
377A

Looks like the 377A is confirming my suspicion

[The Wind Breezes]

My car's been slowly losing coolant and I can see black particles in the coolant in the overflow tank. I assume my pump will go out whenever it feels like.

[135i OREO]

Sounds like your water pump is going out. Something to look for is, when I would turn on my car, the radiator fan would crank up full speed within like 2 minutes. I'd go ahead and order a water pump and thermostat now and try not to drive the car. Especially if you are getting a yellow check engine and then the red. You run the risk of majorly F'ing things up.

[HyeWarrior]

I tried doing a climate control test to see if the pump would turn on. It does, I hear it turn on, but then the radiator fan comes on full blast within a few seconds as well. All signs seem to be pointing at the water pump :/

[HyeWarrior]

Does anyone have a part number for 2012 N55 135i water pump + thermostat?

I see varying part numbers saying its for the older model 135i's

[rob24ert]

Oh damn. How many miles do you have on the car?


Edit. Nvm just saw. It seems thats the mileage for waterpump. Is yours under warranty still?

[Rob_BMW_PNW]

Originally Posted by HyeWarrior

I tried doing a climate control test to see if the pump would turn on. It does, I hear it turn on, but then the radiator fan comes on full blast within a few seconds as well. All signs seem to be pointing at the water pump :/

What is the 'climate control test'?

[The Wind Breezes]

I kinda want to replace mine preemptively cuz I don't think it's worth getting stranded to save few hundred. 47K miles.

[HyeWarrior]

Originally Posted by Rob_BMW_PNW

What is the 'climate control test'?

Found it on the N54Tech forums

1. Insert key and press start button
2. Turn drive and passenger side climate control to full blast
3. Turn on defroster
4. Manually turn down fan to lowest setting (not off)
5. Press and hold gas pedal for 10 seconds


You should hear the water pump come on with water going through it, it sounds like an electric buzz (open the hood if you want). Mine did make the buzz noise, but no water, and radiator fan came on quickly on full speed.

[HyeWarrior]

Originally Posted by rob24ert

Oh damn. How many miles do you have on the car?


Edit. Nvm just saw. It seems thats the mileage for waterpump. Is yours under warranty still?

5k over the warranty

[stewy604]

If you're replacing the water pump, I'd do the t-stat while you're in there. I just had the water pump fail on our 1'er, car has 50k on it.