Well, some of you know but I've talked to the parts guys and BMW has gone back to plastic impellar water pumps. Its not like the 1st generation ones but the plastic material is suppose to be more stronger/heavy duty.

And just another note, the 2nd gerneration water pump (metal impellar) still do fail.. mainly the bearing will fail and cause coolent to leak thru the "weep hole". It happened to me at 53k miles.

Common complaints for early failure of the pump are coolent leaks, low coolent level, intermitent erratic idle.

Jeez, how hard is it to make a water pump reliable? I've never replace one on any other car... I've also never had a car less than 100K.

Thanks for the info.

Thanks for the heads up man........I had to replace mine just not too long ago.......parents wre pissed cuz they thought I was at fault for it :(

Originally posted by John (PA)
Jeez, how hard is it to make a water pump reliable? I've never replace one on any other car... I've also never had a car less than 100K.
I've had to replace water pumps on just about every car I've owned, except for the POS Nissan Sentra that I had when I couldn't afford anything else. One car I had went through 3 or 4 water pumps in around 110K miles. Maybe you've just gotten all the good pumps, and I've gotten all the bad ones! :)

Jim

yeah - my water pump bearings on my metal impeller one were starting to go bad at 43k so i had to have my whole cooling system replaced due to some of my fan blades puncturing my radiator.

Originally posted by Jon Caldito
And just another note, the 2nd gerneration water pump (metal impellar) still do fail.. mainly the bearing will fail and cause coolent to leak thru the "weep hole". It happened to me at 53k miles.

Did you have a sudden rise in temp. or did you catch it before anything detrimental happened? I changed mine from plastic to metal, not because of increased reliability, since it's a given that a WP is a throw away part, but for increased predictability. If the new metal WP is going to fail, whether it be a bearing or some other issue, there is a better chance of catching it in time due to noise or leakage as opposed to the sudden grenading of the plastic impeller which is virtually undetectable until the event occurs.

Originally posted by Jon Caldito
Well, some of you know but I've talked to the parts guys and BMW has gone back to plastic impellar water pumps. Its not like the 1st generation ones but the plastic material is suppose to be more stronger/heavy duty.

And just another note, the 2nd gerneration water pump (metal impellar) still do fail.. mainly the bearing will fail and cause coolent to leak thru the "weep hole". It happened to me at 53k miles.

Common complaints for early failure of the pump are coolent leaks, low coolent level, intermitent erratic idle.

Jon - Funny you mention failure of the main bearing. My 98 had 34,000 miles on it and my METAL water pump began to fail due to a main bearing. Luckily, it was covered under warranty and didn't cost me a cent. I never thought that I would have needed to replace my water pump so soon....

Originally posted by Jon Caldito

And just another note, the 2nd gerneration water pump (metal impellar) still do fail.. mainly the bearing will fail and cause coolent to leak thru the "weep hole". It happened to me at 53k miles.



All water pumps eventually fail. Its just a fact of life. Like someone else said, every car will have a water pump fail. The failure is usually the seal around the shaft will leak. It usually starts very slowly and goes unnoticed for a while. Eventually you will start seeing a small puddle of coolant on the ground under the car.

Early in March afterwork, I started up the M3 and had a Low coolent level message. I first though of a faulty coolent level sensor but when I checked the expansion tank, it was really low. I never caught it because I dont have a garage to park my car and I dont always observe the parking space that I park into.

Anyways, from the top of the engine bay I couldnt visually inspect leaks. I did a cooling system pressure test and my radiator cap failed. Wouldnt hold pressure. I then pressurized the cooling system and didnt see anything from the top. I raised the M3 to inspect the underneath portion of the engine and found a trail of coolent on and behind the water pump pully and on the bottom of the thermostat housing.

I removed the water pump pully to make sure it was leaking since the leak on the bottom of the t-stat housing can actually drop down on the water pump pully making it seem like a faulty water pump. Well, I found coolent seeping from the weep hole (system is pressurized) and bought a remanf. water pump and installed it.

Where did you find a reman? How much was it?

Well, all or most BMW water pumps are now remanufactured. Same thing goes with when you get steering racks, ac compressors, and transmissions.

Hey guys....where is this 'weep hole' in the water pump? Can you see it if you point a flashlight from top (standing up in front of the car), just to the left of the oil filter?

TIA

JatZilla,

In order to inspect the "weep hole", you would have to remove the engine fan, the alternator/accesory belt, and water pump pully.

I believe the weep hole is on the lower side (passenger side) of the water pump housing.

Originally posted by Jon Caldito
Well, all or most BMW water pumps are now remanufactured. Same thing goes with when you get steering racks, ac compressors, and transmissions.
is it always the case on Trannies? I though you could "ask" for a "new" one off the line.

BMW never ceases to amaze me. And rarely in a good way.

My 92k water pump (plastic impeller) just failed last Tuesday. Sucked because I was going to change it last weekend, but my radiator drain plug was busted, so I waited until this weekend.

Anyway, my pump failed at the bearing, the impeller was fine. Luckily I was able to make it home (albeit with a lot of noise). I have had to add a cup of coolant twice in the last 6 months, so that must have been a sign. The bearings were so trashed I could wiggle the pump shaft about 1/8"!!!

Yup the BMW waterpumps suck, but at least they're easy to swap out. I can do them in 35 minutes now :12:

BIMMER95 -
I think 35 minutes would be a slow install for you. You are the water pump master!

Jon Caldito

Common complaints for early failure of the pump are coolent leaks, low coolent level, intermitent erratic idle. intermitent erratic idle

I was wondering if the water pump being responsible for a bad idle is a general understanding or a fact. My car does not idle in the mornings, after holding the accelerator for numerous minutes and 20 mins of driving the car idles most of the time. I had many friend mechnics look at the car and no avail, i personally changed the ICV, O2, Fuel pressure regulator, fuel filter, plugs, intake manifold gaskets. After changing these parts except fpr the O2, i realized they all worked fine but the car has over 108k miles (95 325i) so i didnt take them out. I am currently looking into the possibility of a bad head gasket, but it had never occured to me that a bad water pump could be the coulprit. If you could please provide any feedback or links, former posts concerning this it will be very appreciated. Thankyou