heya, whenever i start my car up in the morning and the engines lovely and cold, a weird whirring noise can be heard. after a while this noise dies out. to make the problem complicated, the same noise is present whenever my headlights are on. when the lights are on the noise starts but as soon as i turn the lights off, the noise goes away. is this some sort of weird electrical problem? can anyone diagnosis this and give me a walkthrough on how to fix it?? this noise is driving me mad and its my only real bug bear with the car.

 

I would locate where the noise is coming from by holding one end of a tube to your ear and the other end various places around the engine. (Don't get caught in the fan and belts!!) A secton of garden hose works quite well.



Could be and Idler pully bearing, alternator, A/C, water pump, belts, P/s pump etc....My FIRST suspect would be something alternator related. Either the clutch is going bad on the Alt, or you simply have a bad ground somewhere.



Good luck and keep us posted

 

yep, turn headlights on open hood and start listening.



first suspect is the alternator

 

i forgot to mention that the noise only occurs above 20kmh as well. when below that speed it stops.

 

yeah i checked out what the noise was and it is the alternator after all, and to make dead certain that it is the alternator, the battery is no longer charging up very well. bit of a noob-ish question here for you guys, but, is the alternator something that is universal amongst all cars or will i need a replacement alternator from another rx7 s1???

 

you need an rx7 one. i dunno about AUS but here its not a big deal to get one

 

there about $600US here and a pain to locate. the local garage confirmed with me that it was the alternator but when i took it to a specialist i discovered a while ago he told me that the alternator was fine. the alternator itself actually turns out to be one from a series 4 (large power output is handy for the soundsystem thats been installed). the whirring noise was because it was loose and was only running one fan belt instead of two. so two new bosch fan belts went in to solve that problem. sorted out an ignition problem while i was at it and got 4 new ngk spark plugs. now theres no weird whirring noise, no firing up issue and the engine is running as smooth as silk.



thanks for the help guys you all pointed me in the right direction and now ive learnt a fair bit about alternators. im always keen to learn more about the mechanics of the car no matter how steep the learning curve.

 

cool! yeah its hard to tell what you have to start with, without seeing the thing. but yeah s4 is an upgrade