In my years of ownership, yesterday was the first time I've heard that dreadful noise. Even by being well-read here and knowing about the phenomenon in advance, it still puts you aback - until reason sets it.
It's the ticking / tapping / knocking / clicking sound when you haven't started the beast for a while. In my case, it was 14 days. But my beast has been asleep for at least that duration before, in similar conditions.
Why now and never before? Can't say. She's error-free and 3k miles into an oil change. She was last driven on a 30deg F day. The ambient temps have been rather constant until yesterday, when it spiked up to 45deg. That's the nicest day I've seen in a while, so I went for a ride.
Upon startup, the racket is so startling you think "OMG Rod Bearings !!!???#@!". It's really loud. Perhaps 5x louder than "normal VANOS rattle." It's louder from the bottom or wheel wells, than the kidney grills or windshield. You can hear it from the cabin. It's RPM-sensitive. There is no added-vibration.
It doesn't diminish by idling. You drive off gingerly. It's still there. Have faith. It goes away in about 10mi -- pretty much whenever the engine gets up to temperature.
In summary:
Here are some consolidated reference threads:
http://www.m5board.com/vbulletin/e3...n/169592-non-vanos-ticking-noise-video-2.html
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/154057-weird-noise-engine.html
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/152001-werid-clicking-noise.html
Hopefully, this post contains enough searchable keywords for others to find.
A question:
For those rare amongst you that have heard both this sound and actual failing rod bearings, can you contrast & compare them?
It's the ticking / tapping / knocking / clicking sound when you haven't started the beast for a while. In my case, it was 14 days. But my beast has been asleep for at least that duration before, in similar conditions.
Why now and never before? Can't say. She's error-free and 3k miles into an oil change. She was last driven on a 30deg F day. The ambient temps have been rather constant until yesterday, when it spiked up to 45deg. That's the nicest day I've seen in a while, so I went for a ride.
Upon startup, the racket is so startling you think "OMG Rod Bearings !!!???#@!". It's really loud. Perhaps 5x louder than "normal VANOS rattle." It's louder from the bottom or wheel wells, than the kidney grills or windshield. You can hear it from the cabin. It's RPM-sensitive. There is no added-vibration.
It doesn't diminish by idling. You drive off gingerly. It's still there. Have faith. It goes away in about 10mi -- pretty much whenever the engine gets up to temperature.
In summary:
- the scary noise happens when you don't start her for a long period of time
- it's not rod bearings
- don't panic -- it's not going to explode
- go for a ride
Here are some consolidated reference threads:
http://www.m5board.com/vbulletin/e3...n/169592-non-vanos-ticking-noise-video-2.html
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/154057-weird-noise-engine.html
http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/152001-werid-clicking-noise.html
Hopefully, this post contains enough searchable keywords for others to find.
A question:
For those rare amongst you that have heard both this sound and actual failing rod bearings, can you contrast & compare them?