[sandman0615]

Hi all, thanks in advance. any help is appreciated

I have a 2006 325xi. I personally replaced the water pump/tstat at about 120k miles, its been working well and its currently at 173k. I went to start the car yesterday and got the coolant warning. I checked the reservoir and it was really low. Not completely dry but the line was towards the bottom of the tank. Looked around extensively with a flashlight and there are no obvious leaks

I topped it off last night. Checked today and the fill level hasn't changed. I went to start the bleeding procedure (temp max, fan lowest, no a/c or auto, accessory start and pedal down 10+ sec), which i've done on this pump and has worked in the past. The bleed procedure doesn't appear to be starting.

I got a low battery warning after trying for a few minutes, and figured maybe it won't start the bleed with low batt. I let it idle for about 40 mins without being able to bleed the top off to charge the battery. Turned off the engine, tried again, still no bleed.

My plan is to check the reservoir when it cools down to see if any has leaked. If not, i plan to drive it around close by for about 30 mins and check for any leaks. If not, i can hopefully assume its fine, but now that the bleed won't start i'm concerned theres a problem with the pump I can't tell until it overheats.

Is there anything that would prevent the bleed procedure like low batt? Is there any correlation between a pump that won't start bleeding and the low coolant? Is it safe to test drive? I'm really just looking for any insight or advice.

Thanks again

[juld0zer]

Connect a charger and try again or fully charge the battery (best) then try again.

Did you roll the door lock to simulate a shut door before inserting the key?

I usually count to 11 for good measure.

Perhaps the pump is cactus and caused the cooling system to overheat and thus overcome the expansion tank cap and lose coolant?

[sandman0615]

small update

there were no detectable leaks with the car off or at idle. I drove it around for about 30 mins, monitoring the temp with the hidden kombi menu, stayed at ideal temp around 220f/105c.

with the engine hot though, i checked again for leaks and it looks like the lower radiator hose has a small drip leak. mercifully, it looks accessible without having to take apart half the car or even jack it up.

still not sure why the bleed procedure won't start though, the voltage looks good around 13v. Its my backup car so i'll use it for short distances. if the leak stays minor and i can top it off every month or so i'll probably not bother (175k miles, car is on its way out), otherwise it looks like its part number 17127531581