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Topic Review (Newest First)

  • 01-26-2011, 03:36 AM
    Whorse

    Thanks guys!

    Im gonna disconnect the battery every night till the weather is nice enough to work on it.
    not that its doing anything over night but it will calm my nerves after the last electrical fire debacle.
  • 01-25-2011, 10:52 PM
    jimlev

    The easiest thing 2 do would be to unplug 2 pump (

    or the relay in the DME box. As I wrote above the relay switches power to the air pump and the DME controls the relay.
  • 01-25-2011, 10:18 PM
    Whorse

    Im 100% sure its the air pump

    first months of ownership i thought it was the pusher fan turning on but one day i was standing in front of the car with the hood open and engine running and it turned on. Was NOT the fan was the air pump behind the bumper.

    This is scaring me cause last time electrical things were bugging out the car went on fire after sitting for 9 hours.
  • 01-25-2011, 02:45 PM
    Panos

    the air pump will not turn on it traffic >>

    you can confirm its the air pump by unplugging it before a cold start. If you still hear the noise look at idler pulleys and belt driven accessories.
  • 01-23-2011, 08:17 PM
    horse325es

    It IS the air pumps guys

    I got that video from an m5 forum, watch the whole thing it stops after the 120-130 seconds.
    But his only turns on for the cold starts.

    Very weird. Why does mine turn on randomly? I noticed it happens in stop and go when im being lazy with the gas pedal and the car almost stalls out on take off. Does it think it just restarted maybe? but if its only cold starts that wouldn't make sense since the car was at operating temp.

    BTW my noise stopped for now but i know for sure that pump turns on in traffic.

    AND I'm 100% sure it was the same exact noise as the video.

    Andreas
    Queens NY
    BMWCCA# 186796
    86 325es (wrecked by careless driver)
    87 325 300k (project for life)
    00 540is 6spd 180k (daily driver)
  • 01-23-2011, 11:20 AM
    Bmw540san

    +1, that's definitely not air pump, as JimLev said

    it's probably bearing. If you have stethoscope, you could find the exact source, just be very carefull with engine running.



    1998 BMW 540i 6 speed
    Arctic silver, M sport suspension (euro delivery), prod. date 05/98, non VANOS
    Staggered 18" style 32 OEM wheels
    3.15 open differential
    Remus exhaust
    AFE CAI with improved heat shield
    Z3 shifter
    VDO oil pressure and temperature gauges in place of headlight/fog switches
    Powder coated valve covers-satin black
    CDV delete
    Debadged
    AEA DRL module (aftermarket daytime running lights)

    1997 BMW 528iA
    Alpine white, premium package, prod. date 04/97, single VANOS
    Staggered 17" style 32 OEM wheels
    Debadged
    AEA DRL module
    Custom made sun blinds for rear seating area

    2000 Nissan Frontier Desert Runner, AKA "The Work Horse"

    Garage aids:
    Direct Lift Pro Park 8
    Campbell Hausfeld 28 gallon oil lubricated air compressor
    Newair ACP-1400H portable air conditioner and heater
    Auto Enginuity scan tool with BMW enhanced option
    Actron 9135 scan tool-for quick readouts


  • 01-23-2011, 09:07 AM
    jimlev

    Sounds like a bearing, check the idlers, etc (m)

    The secondary air pump runs at a much faster speed than the sound in your video.
    If you speed up your engine does the pitch of your squeal change? If so, this would indicate something that one of the belts is turning.
  • 01-23-2011, 03:28 AM
    horse325es

    This is exactly what i heard

    What controls it? what can be triggering mine? my coolant temp sensor works fine.






    Click if embeded video does not work

    Andreas
    Queens NY
    BMWCCA# 186796
    86 325es (wrecked by careless driver)
    87 325 300k (project for life)
    00 540is 6spd 180k (daily driver)
  • 01-22-2011, 10:21 PM
    jimlev

    Yes, we're sure






    "Drive It Like You Stole It, A Sickness for Quickness"
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  • 01-22-2011, 09:24 PM
    Bmw540san

    I wonder if you have short somewhere causing

    pump to come on and off randomly.



    1998 BMW 540i 6 speed
    Arctic silver, M sport suspension (euro delivery), prod. date 05/98, non VANOS
    Staggered 18" style 32 OEM wheels
    3.15 open differential
    Remus exhaust
    AFE CAI with improved heat shield
    Z3 shifter
    VDO oil pressure and temperature gauges in place of headlight/fog switches
    Powder coated valve covers-satin black
    CDV delete
    Debadged
    AEA DRL module (aftermarket daytime running lights)

    1997 BMW 528iA
    Alpine white, premium package, prod. date 04/97, single VANOS
    Staggered 17" style 32 OEM wheels
    Debadged
    AEA DRL module
    Custom made sun blinds for rear seating area

    2000 Nissan Frontier Desert Runner, AKA "The Work Horse"

    Garage aids:
    Direct Lift Pro Park 8
    Campbell Hausfeld 28 gallon oil lubricated air compressor
    Newair ACP-1400H portable air conditioner and heater
    Auto Enginuity scan tool with BMW enhanced option
    Actron 9135 scan tool-for quick readouts


  • 01-22-2011, 08:28 PM
    horse325es

    Re: Air pump screeching

    Is it only cold starts or all kinds of starting? Maybe my dme thinks its stalling out and restarting?

    Andreas
    Queens NY
    BMWCCA# 186796
    86 325es (wrecked by careless driver)
    87 325 300k (project for life)
    00 540is 6spd 180k (daily driver)
  • 01-22-2011, 08:20 PM
    horse325es

    You guys sure??

    In the summer it would come alot on in traffic for about 30 seconds at a time. When it came on last night was after i got stuck in a little snow and had to spin the tires a few times. I thought this pump comes on to cool off the cats when they are to hot. And yes I'm sure I'm not hearing the electric fan on the front of the condenser.

    Andreas
    Queens NY
    BMWCCA# 186796
    86 325es (wrecked by careless driver)
    87 325 300k (project for life)
    00 540is 6spd 180k (daily driver)
  • 01-22-2011, 09:29 AM
    jimlev

    Right, pump should only come on when the car is (m

    first started and the engine is cold. The secondary air pump is powered from relay K6304 (in DME box), which is controlled by the DME.
    If it is the air pump that is making the noise (and not an idler pulleys, AC, alt, or waterpump) hope for the relay to be bad, otherwise it's going to be a pricy fix.
    The fuse for the pump is under the pass side carpet.
  • 01-22-2011, 09:12 AM
    Craig in Canada

    Re: Air pump screeching

    The pump will not come on in stop and go traffic. It runs for 10-120 seconds (or something like that) at startup ONLY. Unless you were shutting the engine off in this stop and go traffic or I misread your post you heard something else.
  • 01-22-2011, 04:29 AM
    horse325es

    Air pump screeching

    Car sat all day in the snow and it was really icy today. I went for a 40 mile drive, when i got off the highway and was in stop and go traffic I heard the air pump turn on as normal but it was screeching like a loose alt. belt. I remember a few threads on a problem with the egr system and water building up in the pump. I'm assuming the water in the pump froze and is causing this noise.
    Can anybody point me in the right direction? I always thought this was a M50 problem.

    Andreas
    Queens NY
    BMWCCA# 186796
    86 325es (wrecked by careless driver)
    87 325 300k (project for life)
    00 540is 6spd 180k (daily driver)

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