bigrackbuck

My E60 525xi started getting an overheat condition last week, when I cycle the pump through the bleeding process it appears to work just fine, the pump kicks on and off and coolant flows back to my reservoir and I can feel the large hoses pressurize during this process. I ordered a pump & thermostat and opted to only change out the thermostat yesterday since the pump appeared to be working fine. long story short the overheating situation is still there. When i put the code in to watch the actual temperature it starts out low at say 4-10 degrees C. Then it starts to rise normally, the fan kicks on & varies speed. Once the car gets above 80-90 C, the fan kicks into a very high mode. Is it really possible that the pump could be failing even though it tests out okay during bleeding? Or is there something else i'm missing? It was a real blister to access and replace the thermostat, i hate the thought of going through this process again! Also, does anyone have a diagram for my series engine for the cooling system? Thanks

txag_530i

You might have an intermittent fault with either the coolant pump or one of the two coolant temperature sensors. One sensor is located by the engine oil cooler, and the other is located by the lower radiator hose.

I was getting the high temperature message when my pump was dying. I would pull over and turn off the car for a couple of minutes. I restarted the engine and the alarm went away. It was almost as if the pump needed to be reset every-once-in-awhile.

How many miles are on the car? From the small sample that I've read about on the interwebs these pumps seem to go out at around 50-60k miles. My engine's pump went out at 55k.

twh

bigrackbuck,

You need to pull the codes to be sure. I'm betting you need a new pump as well.

I have a 2006 530xi and got a yellow over temp warning on the iDrive the other day. It wasn't a complete failure and I was able to get the car home without it turning turing into the red warning. I pulled the codes and the pump was intermittent. I could see it having RPMs lower than required and then it would work - at least enough to drive the car. I've also replaced my wife's water pump on her 2009 X5. She wasn't so lucky and had the red turn the car off now warning.

bigrackbuck

txag,
My car has just shy of 130K miles on it, to my knowledge and after having everything apart I don't think the water pump has ever been replaced. I have one sitting in a box from ECS at home, but didn't want to throw $400 at it if something else was the root cause. Normally I wouldn't blink if i was planning on keeping the car for several more years, but I've been getting a hankering for a 535i Xdrive, so I didn't want to put unnecessary money into it, but if that's what it needs I want to do right by the car and next owner. It runs like a top!! Do you recall if your pump was still functioning and able to bleed the system when it was going bad? Mine seems to bleed fine?? Thanks!

bigrackbuck

twh,
Is there a way for me to pull my codes without a diagnostics tool/reader? I wasn't sure if there was a way to get the codes like you could on some of the older BMW's? Did you end up replacing your pump in your 530xi? It's a real treat removing it isn't it!! I am kind of kicking myself for not replacing it yesterday while i had the TStat out, it's basically the same amount of work, but an additional $400. thanks!

bigrackbuck

Anybody else have any experience with something similar to what I have going on??
Thanks!

twh

You can pull the codes from a 2006 with the older K-line OBD cable or the newer DCAN+K-Line cable. I have both cables and the both work with INPA.

I did in fact change my water pump and thermostat and the small u-shaped hose that connects the two. If your car has 130K miles and it's never been changed, just do it anyway. It is going to go out at some point. Interestingly, my wife's 2009 X5 electric water pump went out about 18 months sooner than my 2006 530xi. Both cars have about the same mileage.

bigrackbuck

Any other input from others who experienced this? I'm getting ready to do the job again for the 2nd time in 3 days, this time the water pump.

bigrackbuck

Okay, here's the conclusion. I replaced the water pump last night and walla, the problem is fixed! Boy was that a treat to do it twice in 3 days!! My hands look like i put them inside the mouth of a shark, kinda hard to wear gloves in an area that is really too small for my hands already! For anyone else out there who might run into something similar; don't let the bleed cycle mislead you that the pump is functioning properly unless you know how it functions when new. When I went through the bleed cycle by depressing the accelerator peddle for 8 seconds after turning ignition switch on, the old pump would cycle on for about 2-3 seconds then pause for about 7-10 seconds(roughly) then come on again. So it appeared that my pump was working just fine...or so i thought. As soon as installed the new pump and performed the bleed cycle was i ever surprised!! The new pump would cycle on for 13-15 seconds per cycle and the coolant came out with much greater force! It would then pause briefly and cycle back on. No over temperature alarm! Thanks everyone!

twh

Congratulations!