Hi , recently Dec 26/08 me and my friends where driving back from Niagra and madea stop on one of my friends house, we parked the Mini and turn off the engine, when i start the engine again i heard a noise on the engine, its like grinding sound but not loud, did shut of the engine and pup the hood and start it again, same noise. i thought it was just snow cought on the engine or lose part like fan or supercharge, did check my temp guage and seems to be normal and my engine light is off, and im just hitting 90000k, so i drove the mini and i test the supercharge to see if its working, and for sure its working. so when i made another stop to friends place again, then this time the noise is louder so i turn off the car and push it a parkin lot and have it towed. it was towed to BMW dealers and what they say is a problem with the water pump a bering went inn to the pump and made the noise, no idea what bering they were saying, so i did agree to have it fix since it coverd by the warranty. then after a few days they called back and now they said they have replace the pump and bearing but this time the alternator is making the noise, but nto that loud.

my question is is possbile that water pump and alternator are tied inn together and if alternator can cause such grinding noise. or just BMW making money out of.. need your opinion. by the way im driving a MCS 03..

also BMW is charging me $1300Cdn . is that true and im better of getting my alternator fix somwhere else.

thanks for you time... mscmagno

 

It is a puzzling coincidence and may be possible, but then again, a grinding noise sounds like the water pump drive gears on the back of the supercharger have failed from lack of fluid. Read this https://www.northamericanmotoring.co...ater-pump.html for background on this issue. They may or may not have misdiagnosed the source. My water pump recently began to “squeal” instead of a grinding noise and the noise went away after replacing it. Mine was the first water pump “failure” I’ve ever heard about.

Now that the alternator is suspect it directs suspicion in a different direction. The alternator and water pump (via the supercharger) are belt driven by the crankshaft vibration damper. Since you have a 2003 model, you may have the early crankshaft vibration damper that is prone to failure. When the rubber separates from the pulley (will make noise), it causes the pulley to slip or loose grip on the belts, affecting those systems, however, you stated that your supercharger is functioning, so I’ll assume you mean it was producing boost, it did not overheat, and no dash warning lights, so it may not be the cause. Question the service department for more troubleshooting details and ask them to inspect the crankshaft vibration damper. Take tension off the belt and grab the damper from below and push, if it touches the cam chain cover, or wiggles, it is bad.

Sorry I can’t be certain, but that is the way it is when attempting long distance diagnostics.

 

Thanks for the response,i did pull out the Mini out of the dealer to have it check with another repair shop, but i'll check what you told me. but quick question lets its crankshaft vibration damper, is that part of the alternator and do i need to replace the alternator or just that part. im asking due to BMW is charging me $900 to replace the alternator and im looking to find away to save and not to get rip off.. thanks.

 

The crankshaft vibration damper is on the end of the crankshaft, a belt wraps around it and the alternator, it is not on the alternator. Here is a DIY on PDF post #7 that will provide some background on location and replacement. Solid, light weight pulleys are less expensive than OEM, but much controversy surrounds their use. I don't endorse them, but I'm more ambivalent than staunch objectionist.

Be sure to share the information about the water pump gears on the back of the supercharger with the new repair shop. And, have the BMW shop return the other take-off waterpump to you.

 

i got the mini back from the dealer, and they replaced the water pump noise and now is its okay. however theirs a bit noise on the engine not as load as before, this time its sound like a clicking noise below my intercoler, i can only hear the noise when im in idle but when the car start running the noise is gone, did test it out and confirm it when i turn my ac and radio off. according to the dealer my alternator must be replace due to the pulley on the alternator already ceased and the barring is the one that making that clicking noise, it make sense to me. also the dealer told me that i cant drive the mini on the highway unitl i changed the alternator due to the pulley might give up and come off and snap the belt and cause big damage. so now my question is that true? and do anyone have a good idea where i can cheap alternator rebuild or new here in Toronto. and can i still drive it on the highway. im scared to put power on the car when i drive , due last time i did that it made that loud sound that brought me to the dealer i the first place.. any sugestion?