Outer Limits 4x4 Board

Ever since i had the belts changed on my 4.5L 80 series about a year ago it has had a loud whine from the engine. Its there all the time from idle and the pitch gets higher as the revs increase. Fed up with it, i replaced the belts today, without the aircon belt it still whined but without the two alternator belts it was gone. i also replaced the idler pulley as it was a little notchy but the whine is still there. has anyone else ever had this problem?

cheers

Reagan

do the new belts have ripples on the inner edge
there is a idler pulley that contacts the inner edge of the belt if the wrong belt is used
you get the noise

Could be a noisy bearing in your alternator...

Jeff80 wrote:Could be a noisy bearing in your alternator...

or a water pump.

Try running without idler bearing, but with the belts on. That's what I did to remove the whine, but now I know about the different belt types I can put it back on. Thanks Thrashlux!

I usually put a long screwdriver on the bolt/nut of the pulley and put my ear up to it. You will hear a whine from the bearing straight away if its the cause of the problem.

Jeff80 wrote:I usually put a long screwdriver on the bolt/nut of the pulley and put my ear up to it. You will hear a whine from the bearing straight away if its the cause of the problem.

A Mechanics Stethoscope is an great tool for this type of diagnosis too. Not overly expensive either. We use ours at least once a week. About $20-$25.

I think this is the same whine mine has at the moment. I thought it sounded like the power steer pump but with my head under bonnet, it sounds like it is coming from the alternator area.

Maybe alternator is working overtime (whine from high load) - what equipment are you running off the electrical system?

Thanks for the help guys.

I used different belts this time (were dayco, now gates), the old belts didn't have ripples on the inside but the new ones do, the whine is a little quieter, i think because the belts are a little on the loose side.

Ill take ur advice and get a stethescope on to it and see if i can hear where its coming from, if not ill try taking the idler off. Im not running much gear off the batteries so the alternator shouldn't be working too hard.

a mates 80 used to sound like it was electric, turns out his alt bearings were stuffed! used to have a real high pitched whine

Mine sounds like a supercharger. Change the belts today and look over it all.

mine is doing this as well it is the alternator on mine

Changed the belts but after looking under the engine I found the Power steering pump was gear driven off the motor. So I started it without the belts on. Yep still there. So I drained the p/s pump and flushed it out a few times with ATF. Filled it up and all good. The p/s fluid was frothing up before so I should have realised that it was just low on fluid.

So all good now.

reagz32 wrote:Ever since i had the belts changed on my 4.5L 80 series about a year ago it has had a loud whine from the engine. Its there all the time from idle and the pitch gets higher as the revs increase. Fed up with it, i replaced the belts today, without the aircon belt it still whined but without the two alternator belts it was gone. i also replaced the idler pulley as it was a little notchy but the whine is still there. has anyone else ever had this problem?

cheers

Reagan

so you mean you have replaced the accessory belt idler pulley too..? I had the same case but after the replacement it all went good. i wonder what's wrong with your case.. hmm.. le' me check.. I actually have a mechanic friend. my as well get some info from him..

Heya mate,

I reckon I had the same thing, although it doesn't sound like the same whine accoriding to your description. I replaced the adjuster pulley and the air-con compressor after using the ole screwdrived it and worked a treat, it seems the bearings in both were a bit rowdy.

Cheers

My vote is with the alternator, mine has been doing this for years still works fine have a spare for if and when it goes. It has been suggested that the alternator has stainless slip rings and that is the noise they make apparently some EA falcons made the same noise and they had ss slip rings.
Rob