New guy here, quick question

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Nov 6, 2012 | 05:50 AM
  #1  
Hello everyone, just bought my first amg ever. I turned to the darkside as my bimmer friends say. its a very well maintained, one owner c36 amg. having owned 2 e36 m3's and one e46 m3, i have to say that i am pleased with my purchase.

just recently a really bad whine has started in the engine bay. upon a closer look, it seems to be coming from around the alternator and having to do with the belt. the noise gets louder at lower rpm's and very loud at idle. I sprayed the belt with belt dressing and the noise went away for about ten minutes before it came back. Also at idle, my low battery light comes on but goes away as i go up gears. I only work about 8 miles from work so right around the time the noise gets very loud, im at my destination.

any advice on what it could be? after doing some research, ive narrowed it down to it being the alternator or the idle tensioner but would really appreciate some direction based on the symptoms.

also, id be very interested in mac based service manual if any exist. i like working on my car and altho a bentley manual would be the obvious choice, id like to have something on my mac for convenience sake.

thanks in advance!
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Nov 6, 2012 | 08:25 AM
  #2  
Welcome! Congratulations on your choice for an AMG and for joining this forum as you will certainly find out we are a GREAT crowd

Regarding the noise you are having, it could be several reasons: idler pulley, alternator bearing or belt. Try starting with the least expensive and change the belt with a new one. That is never a bad idea as belts do break and could leave you stranded in the middle of nowhere. The belt could need some tightening and this would give better pressure at low speed on the alternator, but as you mention the charge light flickers at idle, I have a feeling your alternator is on the brink.
Keep us posted on your findings
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Nov 6, 2012 | 01:41 PM
  #3  
i will check the belt and move up from there. I will definitely return with my findings.

thanks for the feedback!
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Nov 6, 2012 | 09:37 PM
  #4  
How mechanically inclined are you? You can check the voltage on the battery with the engine running to measure the charging voltage. 12.4V means no charge. Generally, 14.2 to 14.4 volts is a standard charging voltage. You may not get that at idle, but have a friend get it up to 3k rpm and you should see that. If it is low, you could have a bad alternator or slipping belt.
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Nov 8, 2012 | 03:53 PM
  #5  
well it turns out the alternator is fine and the culprit is the belt tensioner. unfortunately I also found that im leaking oil from the head gasket on the drivers side .

another issue that Im having is that my car hesitates between first and second gear. I wan to say its oxygen sensors but would like to hear what else may cause it. Transmission has plenty of oil and was serviced before i bought it.

its a really nice cool day in florida and i just put a k&n filter on the car and damn the car can perform, its just too bad i couldnt push it. these things love the cool weather. oh well, id rather save my engine than a couple of minutes of highway fun.

any advice on places to order parts? I usually buy parts from pelican but would like to know where I can get the best deals.
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Nov 8, 2012 | 04:36 PM
  #6  
Pelican is great (they used to be about 4 miles from my house!), but there are many good online sellers. I use and recommend autohausaz.com and BMAparts.com . Those 3 sites should cover 99% of your needs.
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Nov 9, 2012 | 11:43 AM
  #7  
hezitation between 1st n 2nd is a possible o2 sensor problem.
had this problem on my car when I bought it, european cars don't have CEL in instrument cluster.

try your car from standing still, put it in drive and do a hard launch.
automatic upshift from 1st to 2nd will cause hezitation and a possible bang noise from transmission?
rest of the gears will upshift normal.

also try when you driving at very low speed @ 10 - 20 miles/hr or so and launch your car, does your transmission hezitate your ESP flashes?
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