Water pump catastrophic failure

[Harley Monster]

I am kicking myself for not listening to what this car has been trying to tell me for the last several months. We have had a slight chirping noise coming from the fan belt area, not severe, but not normal either. I figured an idler pulley or tensioner pulley bearing was beginning to fail. It is now obvious that it was more than that.

Posted below are some photos of the result of a catastrophic failure of the water pump on our 2001 BMW X5 at 98,000 miles. This pump was changed out at 58,000 miles and is not the original (see explanation below). It is apparent to me that the bearing of the water pump failed taking out the seal and allowing the pump shaft to oscillate and collide in the water pump cavity destroying the impeller. As the shaft oscillated the fan blade took out the shroud and belt along with the blade.

I believe I have most of the parts ordered and the majority of them should arrive today from Pelican Parts. I am replacing nearly everything in the cooling system: New improved Stewart water pump with 20% more flow, 20% more bearing surface, SS impeller and improved seal; radiator hoses; belts; belt tensioners and pulleys; idler and water pump pulleys; fan blade; fan shroud; thermostat and housing and new expansion tank cap. Pelican Parts by the way has provided me with excellent service...they even responded to a tech question email I sent them in only 6 minutes!

I have decided to also do the heater hoses while I am in there, but have not order the parts yet.

I don’t think the water pump cavity is damaged enough to affect the performance of the new water pump as the machined circumference where the impeller rides is not damaged. The only damage is at the rear of the cavity.. I pulled all those pieces shown in the photo of the impeller out of the water pump cavity and I am hoping that any pieces that went through the system will not come back and haunt me later.

I plan on back flushing the radiator with a hose to remove any small pieces that may have made it into the radiator.

I am considering attempting to backflush the engine, but I have not figured out the best way to do this. I am open to suggestions from the pro mechanics on this site or those who know this engine better than I do.

I don’t know for sure, but I think the problem began 3 years ago when I took the X5 in to have the air conditioning recharged at a independent AC shop where I have been happy with their work. The owner called me and told me that my fan clutch was not working properly and I told him to go ahead and replace it. He later called and said they could not get the old fan clutch off the pump and needed to replace the pump too. I told him to go ahead. My guess is that they did not know about the left hand threads as the fan came off very easy for me using a pry bar between the pulley bolt heads and a 10" Crescent wrench.

I question the quality of the replacment pump they used, the pulley flange does say ”Meyle - Germany” on it but it could have been a cheap rebuild of a German pump, I don’t know, but that is my suspicion.

I am hoping that the engine did not overheat too much and take out the head gasket or warp the head which seems to be a common problem with BMW’s that overheat…we will see.


My recommendation...DO YOUR OWN WORK WHEN YOU CAN!

Harley Monster

[chilliwilli]

Sorry to hear...I changed mine as a preventative maintenance measure, thanks to this forum, i also had pulleys, hoses and all belts replaced. I take her in for a full diagnosis twice a year, before summer & winter. Paranoia can be healthy sometimes...

Best of luck with the repairs.

[Werewolf]

Can you give us a little more detail on the chirping noise / sounds before the failure.

How loud?
Only on startup?
Pitch?

[Harley Monster]

Werewolf, I will do the best I can, sounds are difficult to describe.

The sound could only be heard outside the car at idle, we would notice it when we stopped to pick up our mail and when we got out of the car to open our gate. I think it is best described as a soft chirping in sound at the rate of approximately 1 per second. As you walked in front of the car you could hear a mild chirp, chirp, chirp, chirp... If you say that in a soft whisper you get the idea.

I knew it was something in the accessory belts and just assumed it was an idler bearing starting to go out.

Another thing, my wife would report an occasional smell of antifreeze inside the car and lately I had to add maybe a cup at a time to bring the coolant up into range. The adding of the coolant was after she got the low coolant warning. I never saw any type of coolant leak and it never left a puddle, but I am now assuming the seal was beginning to go and the pump was leaking out the weap hole and the smell was entering the cabin.

Looking back on it these were all warning signs that I should have paid more attention to.

The repair is going smooth as silk; however, I ordered the wrong idler pulley on the alternator side...not the spring loaded tensioner, but the idler. Mine is an offset pulley (11-28-7-841-228-M40) and I ordered one with the hole in the center for a different application.

[e30mpower]

Ahhhh man you just saved me so much money... My chirp chirp started last week, I knew when I bought it the dealer said it needed a new fan clutch and some attention paid to its cooling system. Nobody seems to be able to hear the chirp except for me, and everyone has been telling me that cars make noises. I'm like I know my car, I know when it's asking for something to be fixed. You've definitely convinced me to make a service appointment Friday.

[bankerkys]

Ouch.

[Harley Monster]

e30M, if you are going to have the dealer do the work I would ask them to give you prices for not only the pump, but also for the other componets involved...the labor may not be that much more once they get into it. My Bentley book recommends changing hoses every 4 years, my were original and I really don't think they needed to be changed as there were no cracks inside or out and they were soft and supple...but I did them all anyway along with the two tensioners, belts, thermostat. The pulley bearings on the tensioners and the idler are showing signs of wear and I am glad I replaced them.

This is really an easy job...I spent more time cleaning than repairing, the engine looks brand new now.

[djrolo]

Man, I exactely know what you are talking about as my X had that only a few weeks ago. Paid nearly 500€ for repair (including brake fluid and some checks without material).

Water pump break downs don´t seem to happen rarely because my mechanic had 4 other cars (E39, another X, E46 and E36) with same "events".

But the impact of our damages caused more pain and costs than it did with the others.

And I sure know what it means to listen to strange sounds of your car!!!! The only thing is... after the repair this awkward sound still is there when starting the X cold.... but my mechanic tries to calm me down (everything is fixed.... should be fixed...)

[Harley Monster]

djrolo...you might try some silicone spray on your accessory belts, if that quiets the noise down it is the belts...if that does not quiet the belts then I would look at the idler pulley bearings and the tensioner bearings. If you have replaced the water pump there really is no other place the noise can be coming from unless you got a bad pump.

I think one of the problems is these cars are so well insulated we do not often get out of the car with the engine running to hear these warning signs until it is too late. I think it pays to do a "walk around" the car every so often just listening for stuff you would not hear from inside the car...open the hood and listen too. Often your car is warning you it is developing a problem...we just don't listen.