2008 135 72K miles - Possible Water Pump Failure - Need some Help

[RWD FUN]

Not to put another one of these posts out there but my situation is a little different than some others I've seen and need some direction and answers

The main difference is that I am NOT getting any codes, but 10 seconds after I start the car the electric radiator fan kicks on. I had the initial instance where I went into a yellow then red limp mode for coolant temp, but since I don't let the car run long enough to get to that point.

Reading and condensing all the other posts about this I have done the following

1. Checked continuity of the distribution block on top of the battery in the trunk - All good

2. Checked various fuses in the fuse panel behind the glove box. Using the BMW provided card, I checked all the ones next to the engine picture. 4, 11, 12, 16, 17, etc All good. The only info I could find on an actual water pump fuse is #37 is that correct? Which fuses should I check?

3. Checked the one 50A fuse in the ECU/DME compartment in the engine bay on the passenger side. The one that you have to remove the air filter and tray to get to. There was only one fuse on the side toward the front of the car that I could see and it was 50A and was good. Somewhere else I saw it mentioned to be 40A or 60A, but not 50A. Is this the correct fuse or did I miss something?

4. I pulled the connector off the pump and the thermostat housing and made sure they were clean and dry and well seated. I hadn't had any problems and this coincidentally happened right after I splashed a fairly decent puddle. My next stop I noticed the fan on and shortly after the limps modes began. Any ideas if water could have shorted anything in the electrical system.

5. I performed the coolant purge process and the pump does cycle on for 2-3 seconds then off and repeats. The pump doesn't sound great, but I don't have anything to compare it to. I also squeezed the top hose and there doesn't appear to be any pressure or flow. I also opened the reservoir and did NOT see any coolant flowing back through the small pin hole at the top rim. What should the pump sound like? Should I be able to hear water flowing? Why wouldn't I get a code if the pump is not operating properly?

A couple other system questions that have me confused too.

1. It appears that the thermostat is on the outlet (cold side of the radiator) How would it open in that case? What is the wire that goes to it for? Temperature or is it electronically controlled to open

2. Why is the fan coming on so quickly after start up? The code reader showed coolant temp below 170F and the fan still comes on. Is there a different TC that is controlling the fan?

I don't have a problem changing the pump and thermostat, but want to make sure there isn't an odd electrical problem first

Thanks
Joe

[RWD FUN]

Huh, 75 views and nothin'?

I was really hoping a BMW tech or ex-tech might be able to answer these questions or at least why there are no codes if the pump is bad. That's really the last thing keeping me from ordering the parts.

I'd also really like to know about the coolant path and if the thermostat is electronic or mechanical

[Chanka]

Did you get any BMW codes? Same thing happened to me. I pulled 2f15 coolant temp sensor, plausibility

[Miko226]

Water pump failed. 72k was generous of the pump most die around 50k. Mine died at 63k

[RWD FUN]

Originally Posted by Chanka

Did you get any BMW codes? Same thing happened to me. I pulled 2f15 coolant temp sensor, plausibility

No codes on the standard OBDII scanner, but it wasn't a full on scanning system. Would the BMW codes be hidden on a standard scanner?

When you pulled the 2f15 code was it the pump failure or was as simple as the temp sensor failed?

Thanks
Joe

[RWD FUN]

Originally Posted by Miko226

Water pump failed. 72k was generous of the pump most die around 50k. Mine died at 63k

I'm pretty close to calling it that. I saw somewhere else someone mention BMW extended the warranty on the pumps too. I knew about the HPFP extension. Is the water pump extension a myth?

Thanks
Joe

[Chanka]

It hasn't come back yet. It will be hidden from a regular obd2. Im at 66k. Water pump and thermostat should be replaced at our mileage anyway.

[Miko226]

There is no Water Pump extended warranty though there should be since they all die so early its pretty weak of BMW. They will sometimes give a couple of those errors before they actually die and leave you stranded somewhere.

[cadeucsb]

My water pump died at 30k. Yellow coolant icon kicks on, accelerator does less and less, icon goes red, accelerator does little to nothing and coast to should and power off. Look up the issue, let it cool a bit, start it back up, limp from yellow to red, back to shoulder.

Towed to dealer, pump replaced.

[RWD FUN]

Originally Posted by cadeucsb

My water pump died at 30k. Yellow coolant icon kicks on, accelerator does less and less, icon goes red, accelerator does little to nothing and coast to should and power off. Look up the issue, let it cool a bit, start it back up, limp from yellow to red, back to shoulder.

Towed to dealer, pump replaced.

Just had deja vu other than mine is 70k and it's not going to the dealer. Just odd it happened right after a puddle splash.

Seems like Bavarian auto has the best prices around for a complete kit. I have to do brakes too so I guess I'm in for a hurtin'

Thanks all
Joe