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Topic Review (Newest First)

  • 05-19-2010, 10:41 PM
    me_iam

    Found it, had to laugh

    Got a flashlight and looked around nothing obvious. Got out the stethoscope and with some repidation started the car, the noise was very loud and still a high pitched noise like a grinder. Nothing obvious on top end in fact nothing at all with stethoscope. As I was looking around still pushing the stethoscope around the noise came almost to a complete stop. Then I noticed something shining sticking ou to the front that looked like it would have stopped the fan from moving but it did not. Shut down the car, stuck my fingers down to pull at what ended up being the bolt that holds alternator belt tension wheel on the block. The tensioner is a bit crooked, and now the belt is worn. All I need to do is replace the belt, probably the wheel as I think that is what was rubbing against its mount.

    What a relief.http://members.roadfly.com/me_iam/BMW-003F.jpg

    91 850i Calypso
    01 740i Sport
    94 Yamaha V-Max Mod's 120+ HP
  • 05-19-2010, 07:53 AM
    TxGR8White

    mine was no oil to drivers valvetrain, which

    resulted in the camshaft "eating" itself into the all-aluminum bearing cap in front. I also don't want to be an alarmist, but within a couple of minutes the damage was already done and a head replacement was in order. You want to REALLY investigate this well before letting that motor run for any period of time...
  • 05-19-2010, 12:54 AM
    me_iam

    Re: Burnt Valve?

    Thanks Paul, I assumed valve but I may get lucky it is on drivers side on an 850 and does sound as if it is from the front, that is why I first thought it was a fan or something there. Still very nervous about starting it, but will try quickly to see if it is one of these items instead.http://members.roadfly.com/me_iam/BMW-003F.jpg

    91 850i Calypso
    01 740i Sport
    94 Yamaha V-Max Mod's 120+ HP
  • 05-18-2010, 09:43 PM
    poboy

    Re: Burnt Valve?

    On second thought, a loud tapping noise is very different from sounding like a grinder or skill saw. A high pitched metallic grinding sound indicates a bearing of some sort running dry. If you have stethoscope, suggest checking the alternator and power steering pump first (assuming sound is from driver's side). Could still be an oil starved top end, but lets be optimistic.Paul

    '91 850i (225,000 and begging for more)
    '90 750il (159,000 and catching up fast)
    '80 Fiat Spider 2000 (resident hospice patient)
  • 05-18-2010, 09:21 PM
    poboy

    Re: Burnt Valve?

    First thought was that you had a dry lifter, which is fairly common and not of serious concern. This is evidenced by a loud tapping upon start up, but very quickly (5 seconds or so) fades away as oil pressure builds. But after a second read, and I do not want to be an alarmist, but you may have had a banjo bolt back out of the valve train oiler assembly (I'm assuming you're referencing the 850). Result is no oil to most of the top end - rockers, lifters, valves, etc. Not necessarily a common problem, but definitely known. Check the archives. I also would not start her again until more info was available.Paul

    '91 850i (225,000 and begging for more)
    '90 750il (159,000 and catching up fast)
    '80 Fiat Spider 2000 (resident hospice patient)
  • 05-18-2010, 09:03 PM
    me_iam

    Burnt Valve?

    Went to the grocery and on the way back started the car and a loud fast tapping noise came on. First thought was perhaps the fan was touching something. Noise level reduced significantly after about 30 seconds and drive the mile home got it in garage and opened the hood. The noise was/is loud. Almost sounds like a grinder or a skill saw. Checked the oil and it was very low. Topped off oil and started again, let it run for about a minute thinking perhaps it was dry on top. No change in the noise, it is loud. Drivers side. Dont care to start the car again even to get to mechanic. Any thoughts on this?http://members.roadfly.com/me_iam/BMW-003F.jpg

    91 850i Calypso
    01 740i Sport
    94 Yamaha V-Max Mod's 120+ HP

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