Charger noise

[dubpolishers]

Hi guys and girls...

i have a problem

help is needed ASAp..

I drove up to see some freind slast night who live about an hour and half away... i got there fine and switched off.. when coming bk out to start the car.. it starte didling bit funny.. than settled.. i let the car warm up and than when about to move off i hear a noise like a very loud rattle ro vibration of some sort when the car is between 1-2k revs.. i opened the bonnet and couldnt see anything out of the norm but th enosie is coming from the charger area.. any help guys?? advice of what it could be??
im located in e.london so any specialists around here?? bit worried about driving it any where... and not that emchaniclaly minded to look myself... i will try and warm it up and record the nocie and location but ha any one any idea what it could be?? have i killed the charger?? it stop smaking nosie after 2k.. and drives fine after...

Thanks in advance

cheers

[Raw]

A few thoughts;

Probabley not the charger, they tend to go with a bang!
Could be the alternator if it's in the general charger area, that may explain the poor idle?
The fact that a noise occurs at a particular rev range is normaly to do with harmonics and resinant frequency.

[dubpolishers]

this may sound weird but while iw as taking a shower.. i thought about it being the alternator as its situated directly under the charger.. and the noise does sound like from under the charger...

and again as u stated mate would be the cause of poor idle... as the car was about to cut out... all lights dimmed till i accelerated and it came back to life again... but if it was the alternator wouldnt it do it at all tiems?or is it coz the moving part at higher speeds just gets stuck and stops the rattling around??

sorry for all the ques bit of a noobie to g40s..

cheers

[G-spot]

This may sound even more weird, (as I've just got out of the shower,) but are the drive belts taught enough, loose belts can chatter a bit, and also give poor drive to your alternator.  If their original twin belts, check both as a loose or worn one could be the problem.

[dubpolishers]

Ha Ha thats cool buddy im glad your thinknig of my problem and trying to help.. i gave the belts a little tug and they seam ok not loose or too tight.. im no mechanic and am clueless when it comes to engines.. but i have ears and eyes and can at least try and determine where the noise is coming from loooool...  is there any way to check if the alternator is knackered??

am i right in thinknig that if i slide th ebelt off the charger and hand turn it.. and if if turns with out any noises/hardness/ thats it ok to rule it out or not??

cheers guys

[Raw]

You're right about checking for resistance by turning it by hand but that will only tell you about the condition of the bearings and therefore the age/general condition. You realy need to check the output volts with a multimeter to see if it's working fully.

Check the battery output when the engine is off, then start the car and see how the volts (across the battery) rise. I stand to be corrected but from memory the alternator should put out at least 13.5 Volts at idle, a healthy one more like 13.8. rev the engine and see how the volts rise if the volts improve with the revs thaen it's probably the alternator

[dubpolishers]

wicked top man... im not even being able to drive the car either... bit worried about it.. taken a day off on friday to check it out and try and sort it out.. any other suggestions??

so even if the charger span properly it could still be knackered??

cheers

[G-spot]

so even if the charger span properly it could still be knackered??

If the charger spins(or turns) without any mechanial noises or interferance, then you could be safe in saying its not shot yet, if its not been serviced for a long time then I'd recommend getting it done, as worn apex seals can liberate their retaining groove, and jam between the compressor(G-Lader) walls and cause a rapid failure, by the time you know about it your scroll and casing will most likely be unrecoverable.

[dubpolishers]

Dam... also if it was the lader would it happen between low revs and after 2k revs be normnal or would it happen all the time... and happens on idle.. is whats confusing me.. if the charger was shot it owuldnt boost and respond as normal.. or would it??

[PeteG40]

chargers can be worn and still work - thats the danger really.  You only really know if its got history behind it.

[dubpolishers]

what work properly mate?wouldn't ther ebe a difference in power of some sort or not?sorry guys its me first g40

[PeteG40]

its the bearings in the centre that wear, and the charger will spin and boost right even when these are worn - but due to increased float, the centre scroll will be rubbing against the other two halves. if it carries on doing this then the scroll will wear out and the charger will go bang!

[dubpolishers]

ahh dammm looks like its my charger than... it was only serviced around 1000ms ago..

what can i do to prevent this happening again?

[Raw]

Just to clarify, everything I said was about the alternator not the charger. Who serviced the charger 1k ago?

[dubpolishers]

Just to clarify, everything I said was about the alternator not the charger. Who serviced the charger 1k ago?

not sure mate the previous owner had it done.. looks like its my charger tho from talking to afew other peeps... any one got one for sale ?? not a happy bunny considering its my first g and only had it less than amonth.. any1 in london area wanna take alook??

cheers