Help please

[56wedge]

Worried owner of a 1997 540I 6 speed. 175,000 miles. Within the last 60 days, 3 exploded fans. First repair was a new fan blade and clutch. Second repair was new fan blade and new motor mounts. Latest incident ruined radiator, small dent in hood. Repair shop is completely stumped. Any input / advice would be great.
Thank you.

[osc911]

The new viscous coupling (clutch) could be faulty. How did you test it?

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[BimmerBreaker]

Did they at any point replace the water pump?

How are your engine mounts?

[56wedge]

Thanks for the quick replies. Nothing was mentioned about the clutch. It is the original clutch. Could you tell me how this might be the culprit? Yes, the water pump has been replaced - about a year ago.

Thank you again.

- - - Updated - - -

Sorry, I forwarded bad info. The clutch was replaced. It was new last month.

[easymoney]

Were the parts recently replaced aftermarket? I understand new but if they were substandard and cheaper then you will run into problems like you are having now.

[BimmrMeUpSnotty]

The important question we should be asking you is..... What brand clutch fan did you buy?

[AquilaBMW]

Thanks for the quick replies. Nothing was mentioned about the clutch. It is the original clutch. Could you tell me how this might be the culprit? Yes, the water pump has been replaced - about a year ago.

Thank you again.

- - - Updated - - -

Sorry, I forwarded bad info. The clutch was replaced. It was new last month.

If the fan clutch is bad, it can cause the fan to rotate at a higher RPM than it is supposed to. As I understand it, a bad clutch can cause the fan to rotate at actual engine speed which can cause a catastrophic failure such as you are experiencing. The clutch is usually the main culprit in situations like this.

Have you seen a rise in engine temp during this period? If the clutch is faulty, another indication could be higher temps like in traffic or such.

[edjack]

If the clutch is seized, I would expect the engine temp to remain normal, as it's fully engaged. A seized clutch will cause a loud fan noise at off-idle engine speed.

I'd be prone to suspect front engine mounts, at this mileage, allowing the engine to move around under acceleration and cause the fan to contact the rad.

[56wedge]

Thank you all for responding. All of the parts have been OEM. They tell me this is all they use in their repairs. edjack, the engine mounts where replaced after the second incident.

Is it common for a clutch to "bad" out of the box?

Also, as I replay the failures in my mind one piece of information stands out. All three times I was pulling away from a stop. Not fast at all. Controlled, in 1st gear not reaching more than 15mph. Bang. I hope this information and my answers to your questions helps.

Thank you all again.

[AquilaBMW]

Edjack - you are spot on that a seized clutch will cause a loud noise - seems OP hasn't reported that. However, I have seen cars run higher temp in traffic due to a bad clutch.

56wedge.... have you visually checked the fan with the engine running to see if there is a wobble at all? I believe you said the water pump was replaced, but I'd still give it a visual check. Also, as others suggested, I would check the motor mounts again. could be the engine does indeed move as you pull away under power. You can check for movement with the car stationary and someone revving it up while you watch.... just be careful.

[56wedge]

AquilaBMW, et al., A quick update. The shop has replaced the radiator and fan. They also replaced the top radiator hose - they said it had some minor damage but didn't know if it caused the problem or was damaged as a result of the fan exploding. At this point they have told me they still do not know what caused this to happen three times. They seem to think the radiator hose that was replaced was very, very close to the rotating fan blades and think it might have been the wrong hose. The hose wasn't damaged in the two earlier failures, so I'm skeptical and worried about driving the car. I was offered a diagnosis (not by the shop) not previously mentioned - crankshaft crank - thrust washer? They are worn out and causing the crankshaft to move forward when pushing in the clutch and accelerating causing the water pump / pulley, etc. to move slightly affecting the fan. Your thoughts would be great. Thank you all again.

[1999 540i m]

AquilaBMW, et al., A quick update. The shop has replaced the radiator and fan. They also replaced the top radiator hose - they said it had some minor damage but didn't know if it caused the problem or was damaged as a result of the fan exploding. At this point they have told me they still do not know what caused this to happen three times. They seem to think the radiator hose that was replaced was very, very close to the rotating fan blades and think it might have been the wrong hose. The hose wasn't damaged in the two earlier failures, so I'm skeptical and worried about driving the car. I was offered a diagnosis (not by the shop) not previously mentioned - crankshaft crank - thrust washer? They are worn out and causing the crankshaft to move forward when pushing in the clutch and accelerating causing the water pump / pulley, etc. to move slightly affecting the fan. Your thoughts would be great. Thank you all again.

Sounds like you need a new mechanic!