I have only been visiting this forum for about 3 months or so. Several times I have seen people posting about replacing the waterpump in their 1996 328i regardless of its condition because of a plastic impeller used in its construction. I just couldn't see replacing a part that wasn't broken so I call up my local BMW service department and they said, "Hey, don't worry about it. Its fine, I've never heard of one of them going bad." Wouldn't you know it 2 months later my waterpump impeller explodes into a bunch of pieces and I'm stuck on I-95 during rush hour. The tow truck alone cost 150% of the cost of a new waterpump. I ended up having to have my waterpump and thermostat replaced.
My mechanic said that he flushed the system a couple of times. Do I need to worry about any residual plastic piece floating around in there or will the metal impeller finish them off. Thanks for all of the great advice. I will definiately be a little more proactive in the future.
Well.. how bad did the impellar break apart... did you get to see that???... If he flushed the system twice.. then he has done all that he can to get anything out. If there is something in there.. it will do one of two things.. either deteriorate into pretty much nothing... or cause problems with your new impellar.. which I dought.. but I've heard stories.. You should be fine... The big thing is.. just as long as none of those pieces make it to your radiator.. you'll be fine.. if it does.. you've got a busted radiator that leaks... due to a piece of plastic... and has been logged by the high pressure... You should be fine.. just be careful.. and pay attention to the temp gauge... Good Luck!!!!
Yes... only production cars from 96 and earlier have plastic impellars... no worrys...
As you know I have a 97... which would also mean I have the metal one.. but this part has failed on me also... if you are reaching 100k.. I would say go a head and change that sucker.. you might learn something.. also replace your thermostate... both would be a good idea...
I took apart my old water pump and came to find the seal that kept the impellar shaft inner workings clean of coolant and such.. wore.. and from my best guess leaked coolant into the inner workings.. and eat the inner shaft bearings.. till the shaft it self let go... hence the mere fact my fan would wobble around.. because the shaft the held it still while it turned was broken..
Think about this as your mileage creeps up on you...
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.