[dabruguy]

I had the water pump and thermostat put on last december, just today (of course it snowed last night) on my way to work, I got about 10 minutes away, and the Coolant Temperature light came on my dash, and the car went into LIMP mode, I was next to a gas station, so I went in and bought a gallon of anti freeze, it hardly took any. I was able to start the car (after approx. 10 minutes) and got 3 miles before the light and LIMP mode happened again.

I was able to get the car back home but had to stop multiple times when the LIMP mode kicked in
2009 bmw 328i (with 133,000)

[techwhiz]

Water pump again.

[tlow98]

it's odd for an OE N52 water pump to go this early. Check the codes and report back. We can't help until we get that info.

[iqraceworks]

Originally Posted by techwhiz

Water pump again.

Yep....waterpump or thermostat.

The motor is getting hot....plain and simple. Have you tried doing the "purge mode" with the water pump to see if you can hear it running?

[dabruguy]

tell me of this "purge mode"
I will look for codes tonight when I get home, driving the wife's jeep today

[nsjames]

Originally Posted by tlow98

it's odd for an OE N52 water pump to go this early. Check the codes and report back. We can't help until we get that info.

pump was replaced.

we don't know if it was an OE quality part or not.

OP, you need a way to read codes if you ever want to entertain the idea of diagnosing the car yourself.

don't use regular coolant.

and quit driving it until it shuts off from the over temp, unless you want to also do a headgasket/head job.

[dabruguy]

this was an aftermarket pump not from the dealer, but from AutoZone,
I just started it again, no leaks
this comes on the dashboard when it is warmed up

[dabruguy]

no codes but I only have a handheld to see check engine codes

[iqraceworks]

Originally Posted by dabruguy

no codes but I only have a handheld to see check engine codes

Download the MHD app.....I'm pretty sure it will let you scan codes for free.

[relative4]

Originally Posted by dabruguy

this was an aftermarket pump not from the dealer, but from AutoZone,

And there's your answer. But you should still get a proper interface. ISTA, MHD, ProTools, Carly, Foxwell, Launch.

[gbalthrop]

Originally Posted by dabruguy

I had the water pump and thermostat put on last december; just today (of course it snowed last night) on my way to work...the Coolant Temperature light came on my dash, and the car went into LIMP mode, I was next to a gas station, so I went in and bought a gallon of anti freeze, it hardly took any. I was able to start the car (after approx. 10 minutes) and got 3 miles before the light and LIMP mode happened again...
2009 bmw 328i (with 133,000)

Originally Posted by dabruguy

this was an aftermarket pump not from the dealer, but from AutoZone; I just started it again, no leaks; this comes on the dashboard when it is warmed up

Originally Posted by dabruguy

no codes but I only have a handheld to see check engine codes

Here is the TIS circuit diagram for the Coolant Pump for the 2009 328i, with N52 Engine (make sure you have N52 & NOT N51):
https://www.newtis.info/tisv2/a/en/e...ooling/vFKjkjB

You need to get a PLAN for how to properly diagnose what is happening. The 1st SWAG is that the Coolant Pump is NOT running, at least some of the time, but that ASSumes a number of things you have NOT stated or ruled out:

1) What is the ACTUAL Coolant Temperature (a) as reported by the ECTS (Engine Coolant Temp Sensor) to the DME, AND (b) as measured at the OFH where the ECTS is located, using an Infrared Thermometer? You said you had NOT lost any significant amount of coolant. It is POSSIBLE that you don't actually have an overheat issue, just a ECTS signal to the DME indicating ~ 115C to 120C Coolant Temp, causing warning lights to come on, and Limp Mode. You can read ECTS signal temp either with "Engine Temp Parameter" readout using a Generic P-Code Reader, or using Hidden Menu 7.00.

2) A generic P-code reader CANNOT read the 5 HexCodes related to Coolant Pump Faults: 2E81 - 2E85. There are NO P-Code equivalents for those 5 codes, so if ANY of those codes is saved in DME memory, you CANNOT read them with a P-Code reader. You NEED to use a BMW-specific Scan Tool or Software such as INPA or ISTA in this case.

3) Those BMW-specific Scan Tools or Software can ALSO show you Coolant Pump (or Thermostat) Function under DME Control and the pertinent Coolant Temp in real time, AND allow you to ACTIVATE the pump at various "Over-ride" Speeds, to see if it responds to the speed signal provided.

4) As with ANY Electrical issue (whether real or imagined) begin with checking the fuses. In this case, F37 powers the CONTROL circuit for both the Thermostat & Coolant Pump, and F33 powers the Pump Motor. Also check the Connector to the Pump, X6035 and the Brown Ground wire at pin #4 of that connector for continuity to ground.

You MAY have a bad Coolant Pump, but there are a LOT of other things that should be checked BEFORE you simply R&R a 1-year-old Pump.

George

[Volasko]

Originally Posted by dabruguy

tell me of this "purge mode"
I will look for codes tonight when I get home, driving the wife's jeep today

Taken from Pelican Parts DIY Guide:

Turn ignition ON (do not start engine), set temperature controls in vehicle interior to full warm and blower fan speed to Low. Press accelerator pedal to floor and hold down for ten seconds. Electric coolant pump will run for about 12 minutes to circulate coolant and bleed air from cooling system Once pump has run the cycle, check level of coolant in expansion tank and adjust as needed.

Essentially this is a way of checking if the coolant pump works without driving your car. It should sound like a dishwasher running once you start the bleed procedure as it forces the pump to run to push out all the air in your system. If you can't hear moving coolant (it should be pretty obvious in a quiet area) then you know your pump has failed. It is a nice safe check without trying to drive your car and overheat your engine. Also if you can't get heat out of your HVAC vents another sign of a failed motor (no flow of coolant = no heating inside your car).

From all signs you've mentioned this would be a text case failed coolant pump motor.

[banglenot]

FYI: The only replacements for the N52 pump should be BMW or Pierburg (the OEM builder).

There are low quality products coming out of China, which Pierburg has tested and found severely compromised, and crap out early.

On FCPEuro, the Pierburg is $260, and the BMW original is heavily discounted at $320. Even BMW Atlanta is down to $292 for the BMW original.

The Autozone Duralast (whatever that is) is $371. They claim lifetime warranty. Dump it and get the right product. No reason to buy cheap knockoffs.

In the meantime: NEVER drive a BMW engine with a failing waterpump. Even a mile. Flatbed it to somewhere to fix.

[dabruguy]

thanks for the info on FCPEuro, good prices there, I will be purchasing the Piersburg from them.