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Idiot Alert - Idle car.

Discussion in 'General Mercedes-Benz Related Discussion' started by Unsound Methods, Jun 12, 2019.

  1. Unsound Methods

    Unsound Methods Senior Member

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    Morning all.

    Ive been away and the weather is a bit rubbish at the moment, and Ive not had my 91' 300SL-24 out of the garage for a couple of weeks, so i decided to start the car up for 15 minutes (as per a mechanics advice on not using a car through the winter) to give the battery a boost.

    So start her up and waddle off to do some other bits, 45 minutes later i remember the car is still running. duh ...

    I nelected to check the temp dial, and the car has cooled down considerably. but theres no smoke or terrible 'burnt to failure' smell so im assuming/hoping ive not done any damage? I'm guessing its not entirely a good thing leaving it running for that long?

    Could I have done any damage or is 45 minutes nothing in the grand scheme of things?

    cheers
    Dani
     
  2. Naraic

    Naraic Moderator

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  3. OP
    Unsound Methods

    Unsound Methods Senior Member

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    I do like an unambiguous answer! ;)
    thankyou Naraic!
     
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  4. JDPEClassUK

    JDPEClassUK Active Member

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    I agree - no damage, but would be good to give it a run to clear any coking caused by long idle running for 45 mins.


    Sent from my iPhone using Tapatalk
     
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  5. RhodiBill

    RhodiBill Senior Member

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    No - None - Nada....

    NB. But the only thing I do do if I do this is to leave the window open just in case the car decides to lock itself for some strange reason.... ;)
     
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  6. MalcQV

    MalcQV Senior Member

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    I store both my 360 (in a garage) and recently my Z3 (outside with a cover) and on battery conditioners in the winter months and only start them if I need them moving. When I do run them I do so for at least 25-30 minutes so as everything gets warm. Ultimately the most engine wear occurs prior to getting to temp. So whilst idling warms the car it does so slowly and causes more wear.
    This is why today the owner's manual tells you to start the car and go, not to idle. It warms up quicker and therefore less wear.

    There's lots of contradicting information on storing cars both long and short term (I call winter storage short term) regarding running the engine to push oil round (obviously good) down to cold temperatures leading to high fuel content (choke) and bore wash causing none lubrication (bad). You take your pick :D

    All that said tolerances on newer engines are tighter and on an older design it possibly does not apply the same. Either way 45 minutes IMHO is probably actually better than 15 so long as it does not overheat. In future i would say about 25 minutes is best.


    Better still if you can actually drive it then that is the best.
     
  7. OP
    Unsound Methods

    Unsound Methods Senior Member

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    thanks MalcQV, thats muxh appreciated. What battery conditioners do you use? perhaps that might be an option worth considering.


     
  8. Uncle Benz

    Uncle Benz Senior Member

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    45 minutes? Provided the cooling fan works it's fine. Embarassing incident, some years ago I was closing up the workshop and I had to bring an S500 in from the lane into our secure compound. The battery sounded low, so I parked it and left it running while I brought the other cars in and locked the workshop.
    The next morning I was opening up and I thought "I can hear an engine running, whisper quiet but something definitely idling". Yup, I'd left it running all night. On the plus side the battery was fully charged.
     
  9. umblecumbuz

    umblecumbuz Senior Member

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    Smart battery charger/conditioner?
    C-Tek seems favourite, but there are several similar on the market now for a lot less money. I paid around £30 for mine. My friends now use it almost as much as I do!
     
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  10. EmilysDad

    EmilysDad Senior Member

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    Ooops! :rolleyes:
     
  11. daibevan

    daibevan Senior Member

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    Did you top up the fuel? ;);)
     
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  12. Uncle Benz

    Uncle Benz Senior Member

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    It had used a fair bit as I recall, but it didn't run out
     
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  13. rorywquin

    rorywquin Senior Member

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    Wouldn't it be better to take the car for a run on a nice day and get everything moving?

    I don't believe that 15 minutes of idling will even put back the energy used to start the car.........and if your alternator is not functioning properly, you could possibly be running the battery even flatter.

    The other danger is exhaust fumes (if car does not have a cat converter, you are also getting a garage full of carbon monoxide).
     
  14. OP
    Unsound Methods

    Unsound Methods Senior Member

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    We havent had " a nice day" for almost 2 weeks. ;) - normally this time of year i'd be using it all the time but weather and work have curtailed that a bit. unfortunately the stitching is coming undone around the soft-top window so it isnt water tight at present, so i dont take it out if theres any chance of rain - at the moment there little chance of anything else it seems...

    It seems to do the trick over the winter months when i dont use it. It fires up very quickly if i run it for 15 (or so) minutes every week or two. But I am considering a charger for next winter.
     
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  15. MalcQV

    MalcQV Senior Member

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  16. Capra

    Capra Senior Member

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    Are there any dangers of running a car at idle overnight?
     
  17. Uncle Benz

    Uncle Benz Senior Member

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    Well it isn't something I would generally do! Plenty of risks. It could have overheated, caught fire and burned to the ground. Luckily I got away with it, and I have been careful not to repeat the mistake. I'm wishing I hadn't mentioned it now!
     
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  18. LostKiwi

    LostKiwi Senior Member

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  19. stwat

    stwat Senior Member

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    It also promotes moisture build up in the oil and breather systems.
     
  20. RhodiBill

    RhodiBill Senior Member

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    I can well understand what you did because they are whisper quiet. If mine is idling from only a couple of metres away I cannot tell if the engine is running. Even inside I occasionally look at the Rev Counter because I think it has stalled for some reason - but it hasn't....
    So if you forget you've left it running there is no audible warning letting you know you have!
     

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