[Chocolate Lab]

Hey guys, I'm in the middle of my long-planned first cooling system overhaul and so far it's going fine...

But a quick question: got my water pump out and it has a metal impeller! And it's an original BMW, not a Stewart. Now I see why people say the Stewart looks like a work of art... This one does, too.

It looks perfectly fine and doesn't sound funny or act like the bearings are bad... Should I replace it, or leave it in there? I'm almost tempted not to change it even though it has a ton of miles on it. My car has 166k and I can't imagine putting 25k more miles on it.

Anyway, I'd heard that BMW used to use metal impellers many years ago, but I didn't expect my car to have one.

Thanks for any advice!

 

[330ciandr6]

If you have a new one, and have the old one out, I would definitely install the new one.

 

[dmax]

Hey guys, I'm in the middle of my long-planned first cooling system overhaul and so far it's going fine...

But a quick question: got my water pump out and it has a metal impeller! And it's an original BMW, not a Stewart. Now I see why people say the Stewart looks like a work of art... This one does, too.

It looks perfectly fine and doesn't sound funny or act like the bearings are bad... Should I replace it, or leave it in there? I'm almost tempted not to change it even though it has a ton of miles on it. My car has 166k and I can't imagine putting 25k more miles on it.

Anyway, I'd heard that BMW used to use metal impellers many years ago, but I didn't expect my car to have one.

Thanks for any advice!

166K and you're only putting another 25K on it? Why not just part it out while the system is drained.

They won't feel anything now with that life giving fluid out, OP. It's honestly the nicest time to put it down.

220,220 today...don't know what time that will be! :bawling: Another e46 gone.

Is there some sort of :gong: smilie for that?

'Very disappoint' poster of something appropriate!

 

[Chocolate Lab]

If you have a new one, and have the old one out, I would definitely install the new one.

Because of the bearings? I listened really closely for that, and it feels and sounds exactly like my new one...

I guess I was thinking that even though I got an OEM, I would hate for something to go wrong with it when this BMW one looks clean as a whistle and doesn't have the infamous plastic impeller. And now that I know how to do this and it's really not that bad, I wouldn't mind replacing it if it ever showed any signs of trouble. But maybe you're right and I should do it now. I was kind of thinking I could put the new one in my X3, which has 85k and I'm sure does have the bad impeller, but I guess I could always put the metal BMW one in there if I needed to.

And DMAX, maybe I was being conservative. :craig: I just don't drive as much as I used to... Several years ago 25k would only be about 14 months year for me!

Actually, now that I've taken everything apart and looked at it, the more I think the only problem I was having was my radiator fan after all. The whirring sound I was hearing was my pulleys, which were all going bad. But it's fun (and cool) for a newb like me to take all this apart and look at every part separately. Thanks to the board for all the help on that. (Not that want to jinx myself... I'm not done yet!)

Anyway, back to topic, I wonder when BMW starting using the dreaded plastic impeller... Shame they didn't keep making this metal one.

 

[dmax]

Because of the bearings? I listened really closely for that, and it feels and sounds exactly like my new one...

I guess I was thinking that even though I got an OEM, I would hate for something to go wrong with it when this BMW one looks clean as a whistle and doesn't have the infamous plastic impeller. And now that I know how to do this and it's really not that bad, I wouldn't mind replacing it if it ever showed any signs of trouble. But maybe you're right and I should do it now. I was kind of thinking I could put the new one in my X3, which has 85k and I'm sure does have the bad impeller, but I guess I could always put the metal BMW one in there if I needed to.

And DMAX, maybe I was being conservative. :craig: I just don't drive as much as I used to... Several years ago 25k would only be about 14 months year for me!Actually, now that I've taken everything apart and looked at it, the more I think the only problem I was having was my radiator fan after all. The whirring sound I was hearing was my pulleys, which were all going bad. But it's fun (and cool) for a newb like me to take all this apart and look at every part separately. Thanks to the board for all the help on that. (Not that want to jinx myself... I'm not done yet!)

Anyway, back to topic, I wonder when BMW starting using the dreaded plastic impeller... Shame they didn't keep making this metal one.

There was only a few years when the composite impeller was bad...I had one blow on my e36.

If you know your other car has a bad impeller, you should replace that...but honestly, whichever car you want to be more reliable, put the one you have in...composite or metal...as long as it's not a crappy walmart WP!

It's right there, just a few bolts away, and is a nice thing to have reliable for four years.

BTW, on the one you pulled, you said it felt fine. Assuming 'fine' is like with other bearings, then it shouldn't spin freely when you turn it. If it does, it's on it's way out...as far as I know...I'm assuming the bearing is similar to others we have in that regard, but maybe not. I do know I've seen a few cars with bearing 'bits' collected on the underskirt, so they certainly can have a bearing issue on top of an impeller one.

It's low hanging fruit. I think it'd be a good idea to just not worry about it for 4-5 years and replace now.

Doug

 

[Alpha Beta]

dmax, you know anything about an expansion tank without a lip? Never seen it before. It's in my car!

btw it's the lip that has the intruction on how to check coolant written on it.

 

[330ciandr6]

All of them have that unless someone pulled it off.

 

[flashmeow]

BMW used to use metal impellar but it was too heavy (messed up bearing) so they went back and forth. let me see if I can remember this correctly:

metal impellar (too heavy. strain bearing).....switch to plastic impellar (too weak due to heat cycle)....switch to aluminum impellar (too weak..welds would break under strain)...then BMW switch to composite impellar (reinforced nylon)

 

[Chocolate Lab]

Thanks for the info, very interesting.

I started to leave the old one in, but went ahead and put the new OEM Saleri in... Though to answer Doug's question, when I said the old WP felt fine, I meant that it felt just like the new one, no play or sound from it, spun just like the new one.

Now I just have to get that lower radiator hose off!

 

[dmax]

Thanks for the info, very interesting.

I started to leave the old one in, but went ahead and put the new OEM Saleri in... Though to answer Doug's question, when I said the old WP felt fine, I meant that it felt just like the new one, no play or sound from it, spun just like the new one.

Now I just have to get that lower radiator hose off!

hose it down with water or wd, and use a large flat head screwdriver to gently wedge it off...go from side to side...wherever you can.

It will come loose about 2 mins. after you give up on it.

 

[Tangent_]

I noticed the same thing when I overhauled my cooling system at roughly the 155,000 mile mark; the water pump looked in great shape. I still replaced it with the Stewart pump I'd bought, but I kept the old one as an emergency spare... If you're going to reuse it, you should at least replace the o-ring so it doesn't leak.

 

[Chocolate Lab]

hose it down with water or wd, and use a large flat head screwdriver to gently wedge it off...go from side to side...wherever you can.

It will come loose about 2 mins. after you give up on it.

LOL... I'm sure.

Was going to update my old cooling thread, but I guess I'll just put it here... Only real snag so far has been that I thought the Dayco/Duralast 89133 would work with the hydraulic tensioner, but it didn't. So I just put the old one back on for now -- changing belts and pulleys isn't too bad so I don't mind doing this in a few days or next weekend. Fortunately, it seemed pretty much okay -- much better than my AC tension pulley and idler pulley, which sounded like it was totally out of grease.

Of course I haven't gotten to the fun of bleeding yet...

 

[new//M3fan]

BMW used to use metal impellar but it was too heavy (messed up bearing) so they went back and forth. let me see if I can remember this correctly:

metal impellar (too heavy. strain bearing).....switch to plastic impellar (too weak due to heat cycle)....switch to aluminum impellar (too weak..welds would break under strain)...then BMW switch to composite impellar (reinforced nylon)

Yep, the bearings were shot on my metal impeller pump. No sure if it was a BMW part or not. Either way I replaced it with a brand new OEM composite WP from tischer BMW.

 

[Alpha Beta]

All of them have that unless someone pulled it off.

Oh no, I can tell this one was made that way. At least there isn't any obvious sign of molestation.

What's more interesting is the pic illustrated in the Dinan cold air intake instruction manual match the shape of the expansion tank!

 

[dmax]

LOL... I'm sure.

Was going to update my old cooling thread, but I guess I'll just put it here... Only real snag so far has been that I thought the Dayco/Duralast 89133 would work with the hydraulic tensioner, but it didn't. So I just put the old one back on for now -- changing belts and pulleys isn't too bad so I don't mind doing this in a few days or next weekend. Fortunately, it seemed pretty much okay -- much better than my AC tension pulley and idler pulley, which sounded like it was totally out of grease.

Of course I haven't gotten to the fun of bleeding yet...

There's a dayco pulley for all three pulleys. Go to Dayco's site and plug in the oem number you have for the part. It'll give you a pulley number.

I did it a month ago...think I might have listed the numbers...maybe not.

 

[Chocolate Lab]

Thanks, Doug... I just messed up on that one. I was pretty certain I had a mechanical tensioner (thought my car was old enough), so I hadn't even looked into the hydraulic one much. And I really thought the 89133 would work on it anyway. My bad.

But that's okay, I'll get one from the BMW dealer Monday. For some reason, the guy there gives me really good prices... Sometimes better than what I can order OEM for online.

Anyway, I've got it all back together, except for the fan, and am ready to start adding coolant back in.

Rookie question here, but is it okay for me to start the car then hop out and check everything? I'm doing this all by myself here. Wonder if I should wait until I can get another set of eyes present so I can shut it off immediately if something happens, or if that's not necessary. I sure would like to finish this tonight, though.

 

[dmax]

Thanks, Doug... I just messed up on that one. I was pretty certain I had a mechanical tensioner (thought my car was old enough), so I hadn't even looked into the hydraulic one much. And I really thought the 89133 would work on it anyway. My bad.

But that's okay, I'll get one from the BMW dealer Monday. For some reason, the guy there gives me really good prices... Sometimes better than what I can order OEM for online.

Anyway, I've got it all back together, except for the fan, and am ready to start adding coolant back in.

Rookie question here, but is it okay for me to start the car then hop out and check everything? I'm doing this all by myself here. Wonder if I should wait until I can get another set of eyes present so I can shut it off immediately if something happens, or if that's not necessary. I sure would like to finish this tonight, though.

You shouldn't need to when you're adding coolant, if you're doing it right.

Follow directions and the worst will be a coolant leak and pulleys out of alignment.

Read more threads on bleeding...like until 'you' bleed.

 

[epistaxis2008]

My 95 e36 had a waterpump go and it was a piece of crap...ur better off with the metal one which is what I replaced mine with...the plastic impeller on mine got jammed and then the spindel or axel in which turns the impeller melted the impeller because the rod was spinning and the impeller was not the crazy amount of friction melted the impeller right off...it was in two pieces when the guy took it out. Although u do not know the miles on urs and if u plan to rid the car soon don't worry but if ur anal about ur car work then do it while its opened up n ur workin on most of it anyway...mine was under 150 bucks so urs shouldn't be much more...good luck bro

Sent from my SPH-M910 using Bimmer App

 

[Optio]

That stainless steel impeller water pump was only used in model years 1999 thru 2000. It is a near bullet proof design and the reason later cars used the composite ones was to save some cost. I know of 1999 to 2000 E46 with more than 200,000 miles and still going strong on that stainless steel water pump.

 

[MercForHire]

Me too. My car is a 2000 323 and when I did the coolant overhaul at 125k miles, the original pump was a steel one. The waterpump was solid. Thermostat was kinda worn out.
I think if I didn't do the water pump, it still can run couple of years.
Oh well, preventive maintenance.