Water pump failure at 43k miles!

[digitaljok]

Heading home from Las Vegas last weekend, the water pump on my '03 X5 failed. Of course being a Sunday, no dealers were open, so I had to leave the keys in a drop box and rent a car to get back to LA. Fortunately, BMW replaced the pump and fan belt under goodwill (thanks goes to Danielle the SA and Curtis the manager at Desert BMW of Las Vegas).

I asked them to check the cylinder head and block for warping, but it doesn't sound like they got to that. How do I know if there was any damage to the engine from the overheating? Will the engine just lose compression, or could it be more subtle than that (like higher wear that won't be immediately obvious)? Also, have the OEM replacement parts switched over to metal impellers or I am just going to have this problem again (and again)?

And for the record, has anyone here experienced a water pump failure earlier than this? 43k miles is really ridiculous. Especially when you're in the middle of Las Vegas trying to get home on a sweltering July Sunday.

[vinuneuro]

Our first water pump failed at 35k miles. Second one failed at 80k. From my experience, the bearing in the pump assembly is what is more likely to fail.

[asawadude]

BMW now sells an OEM replacement water pump for 3.0i with a composite impeller, replacing the previous metal impeller model which replaced the original plastic impeller model.

The plastic impellers would basically deteriorate from heat, contamination, ice, etc. All it takes is one strategic crack on a blade or the shaft and the impeller would start the process of disintegrating.

Waterpumps with the metal impellers are not always the answer. There are several aftermarket brands as well as some BMW out of date OEM stock. The impeller is solid metal and therefore much heavier; the bearings are not up so spec, so they wear out quickly. Watch out for the cheap brands - if you want a good pump with a metal impeller, go to a reputable source like Turner Motor Sports, Pelican, or Bavarian Auto, all of whom who sell the highest quality replacement parts.

The latest version of the OEM water pump uses a composite impeller. My independent mechanic says the composite pump has none of the issues as described for the 2 earlier models. His preference is to install the composite instead of the metal impellers. Based on what he told me, I put in a composite water pump in my '99 328i earlier this year. No issues thus far in 5 months.

[lo_jack]

Originally Posted by asawadude

BMW now sells an OEM replacement water pump for 3.0i with a composite impeller, replacing the previous metal impeller model which replaced the original plastic impeller model.

The plastic impellers would basically deteriorate from heat, contamination, ice, etc. All it takes is one strategic crack on a blade or the shaft and the impeller would start the process of disintegrating.

Waterpumps with the metal impellers are not always the answer. There are several aftermarket brands as well as some BMW out of date OEM stock. The impeller is solid metal and therefore much heavier; the bearings are not up so spec, so they wear out quickly. Watch out for the cheap brands - if you want a good pump with a metal impeller, go to a reputable source like Turner Motor Sports, Pelican, or Bavarian Auto, all of whom who sell the highest quality replacement parts.

The latest version of the OEM water pump uses a composite impeller. My independent mechanic says the composite pump has none of the issues as described for the 2 earlier models. His preference is to install the composite instead of the metal impellers. Based on what he told me, I put in a composite water pump in my '99 328i earlier this year. No issues thus far in 5 months.

And you could get a hold of one of those where?
Part numbers might also be nice.

[Zulu95]

There is a $200 after market, all metal, replacement available from Turner, Bavauto etc. that is much better than OEM. Claimed 20% greater flow.
My pump failed at 37K.

[rogerkiu]

How about the pump for 4.4i V8 engine? Anything I should take care of?

[lo_jack]

I am liking this composite idea though.

What is the point of flowing more coolant past the radiator than stock if you are making no more heat than stock? I am not trying to be insulent but I have never really figured that out. I do know at some point it is possible to outflow your radiator's thermal efficiency, which would actually make you run hotter.

But if you could run at operating temp but not above, you would not need the fan, which is something.

I'm no thermodynamicist though so I am curious.

[fast4d]

I've never had a BMW water pump fail.

the one in the 02 X5 was replaced at 100k miles as maintenance.

I replaced the original one in my 98 3 series @ 55k miles. no need. just a precaution. I used a generic pump and it did not perform as well as the BMW pump. I put a new BMW pump in 20k miles later.

[BimmerDude]

I too had my water pump go out at 72k. Thank God I was already parked in front of my brother in laws house. But I've heard that there is only one type of water pump for the V8. So either way I guess I'm looking at changing this again around 130K. Not bad, my Lexus LS400 needed a new pump around 80K, so I guess it is pretty normal wear and tear on any automobile.

[Wagner]

The OEM water pump was poo, be glad you had it replaced now instead of when BMW would have made the cost your problem.