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Strange Sound and Erratic Starts

Discussion in 'DIY (Do-It-Yourself)' started by slinky66, Oct 21, 2009.

    slinky66 guest

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    OK, BMW DIY gurus, I need your help with this one.


    • Cranks fine but won't start
    • small motor running sound coming from driver side, near firewall when ignition is on (sorry about the low quality image) but that's where the sound is coming from
    • Was able to start car after 12 hours but still heard the sound when the ignition was on

    Any ideas where in the fuel delivery/ignition system this problem is coming from? I did not jump out the fuel pump yet because that small motor sound from under the hood has me going down a different path

    • Member


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    I can't help with your problem, but I can help you with your description of the problem. "Cranking" is "turning over". It means that the starter is engaged properly and it is able to rotate the engine crank as it should. What you meant to say is, the car cranked/turned over, but it would not start. That means you have an ignition or fuel delivery problem, but it eliminates all the inquiries into the starter switch, starter, and battery. That is how we narrow a problem down to its cause.

    sgrabina guest

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    will the car start if you cycle the key (turn the key to position two, turn it off and then turn it back to position two and then start the car) if this makes a difference i would look for a failed check valve what could be happening is as the car sits (overnight or for a long period of time) the fuel could be leaving the fuel rail, lines and back into the fuel tank because of gravity and therefore cycling the key would re-prime the system so to speak so the engine would have fuel to run the engine. If not i would check the fuel pump itself as it can be a source of failure. other possibilities can be fuel pump or dme relays or faulty injectors etc... start with the basics and if it goes beyond your comfort level i would take it to a known quality repair shop or dealer to properly diagnose it because you would need a fuel pressure gauge to attach at the fuel rail to check for a loss of fuel pressure while the car sits.

    sgrabina guest

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    i can't really tell what is in the picture it almost looks like heater valves or possibly the auxiliary water pump. the aux water pump delivers coolant to your heater core(s) depending if you have dual climate control in the car and thus gives you heat during the winter time.

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