sudden/grinding noise -front of engine 95 525i TU?

[Russell]

I suddenly noticed a rattle/grinding noise that seems to come from the front of the engine. No change with air on or off. noise may vary slightly with speed. I can sense/hear in the car at low speed. At higher speeds it seems to be masked by noad noise. Temperature gauge is fine. Performace seems normal.

I suspect alternator related pullies, belt noise, water pump or alternator bearings. Anything else? Can fan clutch make this sort of noise?

Any help is appreciated

[Joestancampiano]

Try taking all the belts off and running engine for a short time. If it is quiet, then put one belt on and try again. This should help you isolate the problem.

Joe

[myblack540i]

Does it come on with the ignition "on" but motor "off"? I have the same thing, and I think I've traced it to the cruise control module. My problem is with the V8, I can't get to it without removing the radiator. So for now, I just roll up the windows so I can't hear it.

[Russell]

Does it come on with the ignition "on" but motor "off"? I have the same thing, and I think I've traced it to the cruise control module. My problem is with the V8, I can't get to it without removing the radiator. So for now, I just roll up the windows so I can't hear it.

[Russell]

As part of the work I am changing antifreeze, replacing plastic thermostat cover with aluminum cover, replacing all belts and pullies/tensioners. While this may be all or even only part of the problem, these items are well overdue. I wanted to do this work myself. However, it needed to be done NOW, not on a weekend.


We also found the plastic shroud around the fan is "crumbling" from heat and age. Parts of it would actualy break apart in your hand. We had to order a new one. I am sure there was some vibration/noise from the shroud as well.

OT- As I drove up to his shop there was such a range of cars sitting there. A super well maintained 1976 2002 automatic, restored 68 camero SS, a new Bentley coupe, Porsche turbo and Audi A6. This is not counting the usual array of BMWs, VWs and "older" Volvos. They specialize in BMWs, water cooled VWs and selected Volvos.



I suddenly noticed a rattle/grinding noise that seems to come from the front of the engine. No change with air on or off. noise may vary slightly with speed. I can sense/hear in the car at low speed. At higher speeds it seems to be masked by noad noise. Temperature gauge is fine. Performace seems normal.

I suspect alternator related pullies, belt noise, water pump or alternator bearings. Anything else? Can fan clutch make this sort of noise?

Any help is appreciated

[RobPatt]

I've got the 'bad vibe' too, need to isloate whether it's a tensioner or a regular pulley.... how much were the pulleys? -Rob '93 525ia @130K


As part of the work I am changing antifreeze, replacing plastic thermostat cover with aluminum cover, replacing all belts and pullies/tensioners. While this may be all or even only part of the problem, these items are well overdue. I wanted to do this work myself. However, it needed to be done NOW, not on a weekend.


We also found the plastic shroud around the fan is "crumbling" from heat and age. Parts of it would actualy break apart in your hand. We had to order a new one. I am sure there was some vibration/noise from the shroud as well.

OT- As I drove up to his shop there was such a range of cars sitting there. A super well maintained 1976 2002 automatic, restored 68 camero SS, a new Bentley coupe, Porsche turbo and Audi A6. This is not counting the usual array of BMWs, VWs and "older" Volvos. They specialize in BMWs, water cooled VWs and selected Volvos.

[Russell]

Rattle/noise sound at idle appears to be reduced or gone. I replaced the two pullies and belt associated with the alternator and PS and water pump. Already did the AC pulley and belt. Parts were about 110 dollars (indy price) and labor for a total of about 200 dollars. Not sure of exact price since I had other items done such as radiator flushand refill (blue BMW antifreeze), fan shroud and aluminum thermostat cover installed.

However when I blip the throttle from idle, up to about 2000 or so rpm, there still appears to be a slight rattle. Wonder if this the "vanos rattle" I hear about occasionally on the forum? Some have even said there is a "vanos repair kit available". Others say the vanos rattle is a myth. I need to find out more.



I've got the 'bad vibe' too, need to isloate whether it's a tensioner or a regular pulley.... how much were the pulleys? -Rob '93 525ia @130K