E46Fanatics - View Single Post - How can I tell if my new water pump is working properly?

seigi009 · 01-09-2013, 12:18 AM

So, I just replaced my water pump (graf), water pump pulley (uro aluminum), idler pulley and belt. After replacing coolant (BMW 50/50 w/ distilled) and bleeding, I started her up and heard/felt a bump coming from the engine. It got me thinking that maybe something happened to the water pump but I can't tell if it is working. I took it for a 10mile test drive and the temp needle never strayed from the middle and my heat works perfectly.

I was told that if you see a small stream of water running into the expansion tank then your pump is good. Well, my old pump stopped making the stream of water into the expansion tank so I replaced it with the Graf one with a metal impeller but I still don't see a stream either when the car is cold or warm. Do I have some clog somewhere?

I am at 120k and my expansion tank is original (replacing next month) and so are my upper and lower hoses. Thermostat was replaced last year.

I searched high and low for an answer before posting this so any help would be most appreciated. Thank you.

01-09-2013, 12:18 AM	#1
seigi009 Registered User Join Date: Jul 2011 Location: Raleigh, NC Posts: 172 My Ride: 03 325i View My Garage	How can I tell if my new water pump is working properly? So, I just replaced my water pump (graf), water pump pulley (uro aluminum), idler pulley and belt. After replacing coolant (BMW 50/50 w/ distilled) and bleeding, I started her up and heard/felt a bump coming from the engine. It got me thinking that maybe something happened to the water pump but I can't tell if it is working. I took it for a 10mile test drive and the temp needle never strayed from the middle and my heat works perfectly. I was told that if you see a small stream of water running into the expansion tank then your pump is good. Well, my old pump stopped making the stream of water into the expansion tank so I replaced it with the Graf one with a metal impeller but I still don't see a stream either when the car is cold or warm. Do I have some clog somewhere? I am at 120k and my expansion tank is original (replacing next month) and so are my upper and lower hoses. Thermostat was replaced last year. I searched high and low for an answer before posting this so any help would be most appreciated. Thank you.