Engine Speed Dependent Whining Noise

[PJPHughes 0]

Hi everyone,

 

My '89 Mi16 (91 K miles, timing belt replaced 2000 miles ago for preventative maintenance) in Boston was sitting for a month and a half. The past two mornings, it's been making a speed dependent whining noise, which tends to go away almost completely once the car is warmed up. It's a bit like the sound a car makes in reverse when backing up...kind of a whirring/whining noise. It's been cold here...temps around -2C.

 

I'm assuming that it is either a bearing in the alternator (rebuilt one from 5 years ago), bearing in a pulley or tensioner (?) or something like that.

 

Can anyone help me out here? Since it goes away, I'm not too worried (at least yet, since I have a 220 mile drive to Burlington, Vermont and back this weekend. I'm not too worried...but just wondering.

 

Cheers,

Paul Hughes

[Jer309GTi 3]

A couple of ideas;

 

Maybe the cambelt is a little too tight. This makes a 'whirring' sound.

 

Easy way to prove it's not the alternator and the pulleys on the aux drive belt is simply to take off the belt to see if the noise goes away. If it does, process of elimination starting with alternator belt tensioner. If not, then cambelt tensioners or belt too tight.

 

If I had to guess I would say it was something on the cambelt side of things because you say it goes away when warm, but check by taking the aux drive belt off first.

 

Did you change the cambelt tensioners when you did the belt btw? It really is good practice to get a 'cambelt kit' (belt and all tensioners), and it's all done then

 

Hope this is of some help to you mate

Edited January 25, 2007 by Jer309GTi

[PJPHughes 0]

Answer made itself apparent last night, when the battery light came on and the sound went away. My initial thought was my alternator was dead.

 

I managed to get the car on battery power to my mechanic's garage...I think I was within about 2 minutes of losing complete power...I had to drive with the headlights off for the last mile as I had almost no juice left! That raised a few high beams at me as people drove by. Turns out the idler pulley has seized (probably due to age, corrosion and cold temps) completely and the alternator belt had snapped. As such, I literally had the 20 minutes of battery life to get me where I needed to go. Great night for it to. -12C here last night in Boston, MA...not a good night to have your car die on you!

 

My alternator was rebuilt 2 years ago, so this seemed weird, but non implausible. I just checked the US Mi16 Yahoo Groups list and several folks suffered the same issue. $225 for a new idler pulley. Yikes! Might as well do a new battery too, since it's 4 years old and is probably ready to be replaced.

 

Nothing like the love of an old car to empty your wallet! :-)

 

Cheers,

Paul

[KRISKARRERA 2 1 Cars]

Idler pulley? What exactly is that though? Do you mean the pulley for the aircon models?

[welshpug 1,626]

IIRC there are 2 idler/tensioner pulleys on engines with aircon..

[KRISKARRERA 2 1 Cars]

Not on mine there isn't. But I do know that when they go they're a rip off from the main stealer!

[Jer309GTi 3]

Mines got one tensioner/idler whatever you want to call it for the aux drive belt

[KRISKARRERA 2 1 Cars]

Yours got aircon then? I know the non-aircon 1.9s just have the belt going from alternator to crankshaft with no other pulley.

[Jer309GTi 3]

Yeah mines got aircon mate. Alternator, crank, aircon and big tensioner pulley on the belt. The tensioner has a square cut out in it for adjusting, like the cambelt tensioners

[KRISKARRERA 2 1 Cars]

Nooooo the square cut out is for set ups where there's a separate belt for the aircon. On Mi16s you have the pulley up as far as it'll go and then you adjust tension via the alterator thingy.

[Jer309GTi 3]

Thats how I did mine. Lucky guess!

[Guest scottcmb]

Yeah mines got aircon mate. Alternator, crank, aircon and big tensioner pulley on the belt. The tensioner has a square cut out in it for adjusting, like the cambelt tensioners

<{POST_SNAPBACK}>

Kriss is write that is the only way you can do it...if you find that when you go to tension the belt and it is getting close to being adjusted as far as it can go.....its time to replace the belt!!!!.....when adjusted make sure you tighten up all bolts that retain the alternator especially the pivot bolt!!!...lol Btw Kriss can you change your pic please???...that cleavage is getting me in soooo much trouble with my Misses

Edited January 27, 2007 by scottcmb

[PJPHughes 0]

Yeah mines got aircon mate. Alternator, crank, aircon and big tensioner pulley on the belt. The tensioner has a square cut out in it for adjusting, like the cambelt tensioners

<{POST_SNAPBACK}>

Kriss is write that is the only way you can do it...if you find that when you go to tension the belt and it is getting close to being adjusted as far as it can go.....its time to replace the belt!!!!.....when adjusted make sure you tighten up all bolts that retain the alternator especially the pivot bolt!!!...lol Btw Kriss can you change your pic please???...that cleavage is getting me in soooo much trouble with my Misses

<{POST_SNAPBACK}>

 

 

I'm back up and running. The idler pulley had completely seized. I think it is due in part to the car unfriendly climate of New England, with big temperature changes, and winters that mean salt, grit, corrosion, and so on. It may have been a bad part too..who knows. All I know is that I recently replaced the brake lines, and my mechanic had to use a blow torch to get them off, thanks to all the salt/rust/corrosion....compare that to the car in Los Angeles where none of these issues occur.

 

The part according to www.westernhemispheres.com is for Mi16's with A/C...so I'm assuming for folks in Europe that don't have A/C that it may not be needed. Mi16s came fully equipped in the US with leather, power glass moonroof, upgraded stereo, power everything, etc.

 

Glad to have her back up and running! So a warning to everyone...if you hear a speed dependent whirring noise, check your belt tensioners/idler pulleys!!

 

Cheers,

Paul Hughes

[KRISKARRERA 2 1 Cars]

I've got it on my 1990 Mi16, and it works, which is quite rare. In the "Old" England we have crap weather too. Lots and salt and rain most of the time and then 30 degrees for about 2 weeks in the summer if we're lucky

 

Incidentally there's seems to be 2 locations for the aircon belt's tensioner pulley - on the sump as on my 1990 car or attached to the bottom of the block as on my old 1992 car, which is probably a better idea really.