coolant system help!

Alright so my water pump went bad and actually ended up imploding in the system. I retrieved serveral large plastic parts from the old pump, but i want to get all the plastic parts out of the system. I have my water pump and thermostat out. Would it be best to leave the engine drain plug in and fill it with water through the thermostat hole and watch for pieces to come out? then drain the system completely? Anyone having any advice on this i would appreciate greatly. It's quite cold in ohio today and would like to get this job done as quickly as possible.

I think that would be the best solution. I can't think of anything that would be better. Would hurt to try it.

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Went ahead and filled it up and drained it out, got alot of tiny small pieces, but no large ones. I'm kind of at a loss here for where the rest of the plastic pieces could be. I have a new pump with the metal impellar design, but really dont want to put everything on, to have to take it back off again for not getting all the pieces out. Would anyone have any ideas on what i could do to insure that there would be no ill effects when putting everything back together? Thanks!

Large pieces probably won't pass through the cooling system passages. The main concern would be blocking the flow to some part of the cylinder head. Have you done a search, here, at bimmerfest, and bimmerforums? I can't imagine this is the first time this has happened to someone.

I've searched both here and bimmerfest, that's where i got the idea of filling through the thermostat with the drainplug in. But other than that i didn't really find anything helpful in my situation. The only other thing i can think of would be to take the lower radiator hose off and see if anything tried passing through to the radiator?

Not sure how you made out, but I would try flushing from the engine back to the water pump. The lower radiator hose would also be a "must check".

The primary passage from the water pump is into the cylinder head. You can pull the engine coolant temperature sensor (at the back of the head, below #6 intake port) and flush back from there. I haven't checked, but imagine this is a pita to get to.

Hmmm? I was thinking of pushing water up from the block drain and see if anything comes out from the opposite direction.

You could use a wet/dry vac and suction out from the wp hole.

Have you tried 'sort of' reassembling the broken pieces to get a sense of how much you're missing?

take the radiator out and flush it.

i would flush the whole system 2-3 times to be sure.

ended up pulling the lower hose, filled through the thermostat, drained from the engine drain plug, blew water through the drain as well. also used a vac and got a large chunk from behind the water pump. reassembled everything and have about an hour on everything with no signs of overheating and hot air coming from the vents. am i in the clear?

Originally Posted by truckcap22

ended up pulling the lower hose, filled through the thermostat, drained from the engine drain plug, blew water through the drain as well. also used a vac and got a large chunk from behind the water pump. reassembled everything and have about an hour on everything with no signs of overheating and hot air coming from the vents. am i in the clear?

Probably at least until the next thing breaks!

Nice going OP...just monitor the temp gauge and for the next few days, check your coolant level. You had the heat on when filling it, I presume. If not, get the heat on, run the car, and expect a low coolant light.

Yes, I did have the heat on while filling it. Bled it correctly and checked the coolant again before I drove again today. It was still perfectly where I filled it up to. Drove another 100 miles today with no fluctuation in the temp gauge at all. Crossing my fingers! Thanks for all the help and e46fanatics for having awesome info to search through!

I need to just replace thermostat, but was planning to replace hoses and water pump with metal propeller. Do you recommend that I replace radiator and expansion tank as well? What brand parts do you recommend?

How old is the car and mileage?

2001 325i with 78k

Originally Posted by spherehunter

2001 325i with 78k

most on here will try to help you out as much as possible when they can. and when new, we all make posts asking questions that have been answered a hundred times before because we are just unaware with our limited experience on the site.

given that, you are asking a question that is covered in depth on at least one sticky and usually at least two or three threads a day.

I'm not above asking questions "spur" of the moment from time to time when I need help, and I need it now, but for goodness sake, search and read the E46 Cooling system guide sticky by E46Mango and then post your questions.

short answer you'll probably get - YES - replace your entire cooling system, and both hoses and all pulley while you're at it.

Good luck!

Originally Posted by spherehunter

I need to just replace thermostat, but was planning to replace hoses and water pump with metal propeller. Do you recommend that I replace radiator and expansion tank as well? What brand parts do you recommend?

Definitely replace the ET. Get a CoolXpert as that is OEM.

You can probably wait on the radiator as those don't completely blow up and drain all your coolant in 5 seconds. If you do get a new one, try to get Behr.

Originally Posted by spherehunter

2001 325i with 78k

Damn that is low miles. I guess the car is garaged. As such, the car must be great shape.
What to replace is a matter of philosophy and how well you know your car and disposable income.
Some believe since you need to change a part and you are already in there, to change it all. Others play the wait and see card.
In addition to the hoses, I would change the ET since they usually fail at around 100k. I've seen radiators that have failed at 100k as well, but not usual. They are cheap and easy enough DIY. So if you have the money, and you're going to have it all apart, then change as well.
Throw in the sensor and she transmission check valve.
There are hose lines that are in the front and accessible to easily replace. Then there are two lines that connect from the ET to the engine that connect under the intake manifold. you may want to plan to replace these at another (weekend) time sine the manifold has to be taken off.

Lastly, since you'll have the front end taken apart including belts, i would recommend replacing belts, tensioners and pulleys. They usually go bad around 100k as well. Make sure you get the correct types (hydraulic vs mechanical).

Hope this helps. Enjoy.

Thanks, The belt is new I was definitely going to replace water pump plastic pully with a metal one. BV Auto have a cooling overhaul kit for 334.95. I have to check out which tensioner I need to get.

Complete cooling system overhaul in a convenient kit! Includes the following components:

Radiator - Nissens
Radiator Expansion Tank
Upper Radiator Hose
Lower Radiator Hose
Coolant Level Sending Unit
Expansion Tank Bleeder Screw
Water Pump & Gasket - With Upgraded Metal Impeller - Meyle
Thermostat & Gaskets - Wahler
Coolant Temperature Sensor

I cant find anything on the Transmission check valve though.

Thanks for your response.

Originally Posted by spherehunter

Thanks, The belt is new I was definitely going to replace water pump plastic pully with a metal one. BV Auto have a cooling overhaul kit for 334.95. I have to check out which tensioner I need to get.

Complete cooling system overhaul in a convenient kit! Includes the following components:

Radiator - Nissens
Radiator Expansion Tank
Upper Radiator Hose
Lower Radiator Hose
Coolant Level Sending Unit
Expansion Tank Bleeder Screw
Water Pump & Gasket - With Upgraded Metal Impeller - Meyle
Thermostat & Gaskets - Wahler
Coolant Temperature Sensor

I cant find anything on the Transmission check valve though.

Thanks for your response.

How about expansion tank cap and belts? water pump pulley bolts? how about fan/fan clutch (assuming you are auto)

as far as metal impeller, that is not an "upgrade" in other words, there's no reason to mention its material.

I am going to replace cap, but belts are new. I will also be changing plastic bleeder screw for a metal one. Fan seems to be newer. Ill have to check. Thanks for the input.

I copied the cooling system kit directly from Bavarian Auto Sport they labeled it as an upgrade not I.