[NGD85]

I am at my wits end here. I’m posting in hopes that someone,anyone has any ideas.

I have a 2014 BMW 335i. The water pump has been cycling on for 2 days now. It does it intermittently. The last time it did this was a few months ago in November.

Mods:
Tune ( Bootmod3)
BMS intake
Catless exhaust
And suspension.

I had JB4 a year ago and when it did this I got rid of the jb4 in favor of bootmod3. It went away for a while

So far I’ve:
Removed jb4 and swapped to BM3
Flashed back to stock after it started doing it agin 2 days ago and it’s still doing it


What the car does is sound like it turns on and then the pump starts to cycle. If I lock or unlock it the pump stops and then restarts after a few minutes. When the car is on it runs flawlessly but it’s killing the battery right now and I’m trying to get to the bottom of this.

Any suggestions would be amazing!
Nick

[IK6SPEED]

Originally Posted by NGD85

I am at my wits end here. I’m posting in hopes that someone,anyone has any ideas.

I have a 2014 BMW 335i. The water pump has been cycling on for 2 days now. It does it intermittently. The last time it did this was a few months ago in November.

Mods:
Tune ( Bootmod3)
BMS intake
Catless exhaust
And suspension.

I had JB4 a year ago and when it did this I got rid of the jb4 in favor of bootmod3. It went away for a while

So far I’ve:
Removed jb4 and swapped to BM3
Flashed back to stock after it started doing it agin 2 days ago and it’s still doing it


What the car does is sound like it turns on and then the pump starts to cycle. If I lock or unlock it the pump stops and then restarts after a few minutes. When the car is on it runs flawlessly but it’s killing the battery right now and I’m trying to get to the bottom of this.

Any suggestions would be amazing!
Nick

Error codes?

[NGD85]

None that were from anything thermostat related. The flash wipes the codes. I’ll check again after I drive it a bit more but nothing glaring

[njdangelo]

Originally Posted by NGD85

I am at my wits end here. I’m posting in hopes that someone,anyone has any ideas.

I have a 2014 BMW 335i. The water pump has been cycling on for 2 days now. It does it intermittently. The last time it did this was a few months ago in November.

Mods:
Tune ( Bootmod3)
BMS intake
Catless exhaust
And suspension.

I had JB4 a year ago and when it did this I got rid of the jb4 in favor of bootmod3. It went away for a while

So far I’ve:
Removed jb4 and swapped to BM3
Flashed back to stock after it started doing it agin 2 days ago and it’s still doing it


What the car does is sound like it turns on and then the pump starts to cycle. If I lock or unlock it the pump stops and then restarts after a few minutes. When the car is on it runs flawlessly but it’s killing the battery right now and I’m trying to get to the bottom of this.

Any suggestions would be amazing!
Nick

How do you know the water pump is cycling? Is that the only auxiliary randomly turning on?

[NGD85]

There is a few clicks and then the pump starts cycling. I confirmed by unscrewing the overflow cap while the car was cold and the water was flowing back into the overflow as it circulated. during this process none of the lights within the car turn on. No fuel pump prime. Just the clicks and the water pump cycling

[upsidedownfunnel]

It could be unrelated to your JB4 issues. It could just be a bad water pump. You figure you have a 2014 with about 75k miles then you got about the usual lifespan for an N55 water pump. Might also want to check the thermostat and look for any leaks and possible corrosion on electronics. It's also probably not a bad idea to check the relay.

[NGD85]

Where/ which one is the relay for the pump? I’ll get under it in the next day or two and check the plugs as well

[upsidedownfunnel]

I have no idea where the relay is. To be honest though, it sounds like you just need to replace the water pump. How many miles do you have?

[claytonkethe]

Originally Posted by NGD85

I am at my wits end here. I’m posting in hopes that someone,anyone has any ideas.

I have a 2014 BMW 335i. The water pump has been cycling on for 2 days now. It does it intermittently. The last time it did this was a few months ago in November.

Mods:
Tune ( Bootmod3)
BMS intake
Catless exhaust
And suspension.

I had JB4 a year ago and when it did this I got rid of the jb4 in favor of bootmod3. It went away for a while

So far I’ve:
Removed jb4 and swapped to BM3
Flashed back to stock after it started doing it agin 2 days ago and it’s still doing it


What the car does is sound like it turns on and then the pump starts to cycle. If I lock or unlock it the pump stops and then restarts after a few minutes. When the car is on it runs flawlessly but it’s killing the battery right now and I’m trying to get to the bottom of this.

Any suggestions would be amazing!
Nick

Sounds strange, almost like a plug is loose and then becoming connected, weird. Looking forward to seeing the solution.

[NGD85]

Originally Posted by upsidedownfunnel

I have no idea where the relay is. To be honest though, it sounds like you just need to replace the water pump. How many miles do you have?

I have over 100k, I bought it used. Aside from cycling while the car is off there is no heating issues and nothing wrong with the pump and or thermostat. I guess ill just have to pony up and purchase a new one next check and see where that takes me. I was just trying to avoid getting a new one if the existing one was still good.

[NGD85]

Originally Posted by claytonkethe

Sounds strange, almost like a plug is loose and then becoming connected, weird. Looking forward to seeing the solution.

If the plug was loose wouldnt it give me issues while the car was in motion vs standing still. Ill still check as not many options left.

[Imperial328i]

Someone said relay and I think that's a good idea. There is a control circuit for the pump and somehow it's getting power when it shouldn't. There's either a short to ground or a malfunctioning relay. Hold off on the pump it may be much cheaper a fix than that.

[Imperial328i]

Here is the N55 cooling schematic. I would check connections at all involved electronics. I'm an avionics technician and I have seen electronics do some wild shit and get fixed by a simple reseating of the connectors.

[NGD85]

That is awesome! I cant really read it too well but it looks like there is a inline 50a fuse? or relay that powers the pump. pg2 integrated supply module?

[SeanFitz335]

Inspect the connector to the pump for corrosion. It is not uncommon for the pump to leak around the connector, causing corrosion in the plug. This can cause a short and electrical demons on the LIN bus.

Ask me how I know.

[BimmerBoy007]

Originally Posted by SeanFitz335

Inspect the connector to the pump for corrosion. It is not uncommon for the pump to leak around the connector, causing corrosion in the plug. This can cause a short and electrical demons on the LIN bus.

Ask me how I know.

I am having the same problem on my 2015 335i (59k miles). Car is overheating but I’m not sure If water pump is the problem. Got it diagnosed at Indy bmw shop and they showed me corrosion on water pump connector. The quoted me $1200 for replacing the whole water pump. Would it be better for me to change connector before water pump to see if that is the problem?