What's that whining/buzzing noise?
 

Over the past 2-3 weeks, I've noticed a whining/buzzing noise from the engine, which increases in loudness and frequency as RPM's increases.

During this period, I've also noticed the engine pops'n'misfires and hesitates under heavy load, so I went ahead and changed plugs, distributor cap, ignition rotor and even fit in a new Crane HI-6 Ignition system to handle the sorts of levels of boost I intend to run once I get this thing on the dyno to verify A/F ratios at the boost levels the setup is designed for.

Anyway, the whining/buzzing seems to have gotten worse/louder and today, after a 20-30min cruise along the FWY at operating temps, I noticed a loud constant squeaky noise coming from the rear-end. It sounds very much like a squeaky pulley or fan belt :eek:

Sounds like I have a freakin bird cage out the back there :(

Now, I'm not sure if it's the Alternator pulley or the Air Con pulley, but the hesitation felt worse as the squeaking got worse.

I suspect the bearings in the Alternator are wearing out and has attributed to the engine hesitation under load and even at steady cruising speeds when operating temps are reached. It does not seem to do it when the motor is cold.

I also noticed I'm blowing brake light fuses left right and centre these days too. Grrrr!

This is really beginning to p!ss me off!

I measured volts across battery terminals at idle and it registers approx 14.1v, which I believe is normal, but I don't know what's happening under load, and whether the Alternator is able to sustain the power requirements of the engine under WOT.

Any advice?

Merv, before you mentioned the squeeking noises, my suggestion was to check the wire from the coil to the dizzy to make sure it is snug. I had experienced the whining & buzzing with speed / pops / misfires / hesitations, etc. when I switched to MSD ignition and noticed that my coil wire to the dizzy wasn't firmly attached at the coil. Pushed it in harder and everything was great after that.

Hi Jim. Thanks for the reply. Before I had the Crane HI-6 unit installed (today), I double checked all leads and seating etc... I pulled out all leads at the dizzy, installed a new rotor and dizzy cap and re-seated all the leads firmly and triple-checked these connections.

The squeaking I refer to sounds very much like a loose/worn fan belt, but it only did that at operating temps and after I gave it a bit of load. Doesn't do it when cold, or when I've taken it real easy :confused:

What's the typical life-span of these alternators? Mine I assume is 15 years old!!!

Engine seems to be idling erractically too and when it stabilises, it seems to be idling much lower than what it use to... now idles at a low 600rpm's or so :confused:

hi merv

why not take the belt off and check the alternator bearing?

Yeh, gunna check all that tomorrow. A mate of mine is going to remove the alt and suss it out and if possible, fit a hot-swap unit in to get me going properly until I can get a K3 unit ($750!!!!). Won't be for a while tho :(

Merv,

My SC has been whining since I bought it, but it got louder over the last month. My belt was a bit worn and my alternator was old. I changed both and my whine is gone and the car runs like a dream. Note, I thought it was running fine before, but it is so much smoother now.

Don

Thanks guys. I've just been chatting with Todd of Protomotive and he tells me the Alternator is dying and I should not drive the car until I can fix/replace it cause it CAN burn out my ECU and Injector Driver (if overcharging)! :eek:

Looks like I'll have to go for a K3 unit asap :confused:

Luckily, a mate of mine is going to loan me a replacement unit to get me out of trouble :)

UPDATE: Well, pulled off the Alternator today and I can turn the pulley with my hand and hear the bearings grinding inside. Not smooth at all, just really rough! The unit is totally screwed! :mad:

I'm just thanking my lucky stars it wasn't OVERCHARGING @ 18v-24v or else I'd be needing a new DME, Injector Driver, Alarm Module and whatever else it could have potentially blown up due to a sustained voltage spike!