Saab Tech Talk (STT)

Workshop for classic Saab models => Classic Saab 9-5 (MY 1998-2010) => Topic started by: Steve440 on 07 May 2013, 11:33:16 AM

Title: Idler pulleys
Post by: Steve440 on 07 May 2013, 11:33:16 AM
I have just replaced the fan belt on my 2002 Aero. It was completely destroyed so I got recovered home.

I fitted a new one and all seems OK but should I fit new idler pulleys? If so where is the best place to buy replacements?

There seems no play and they run smooth but the car has done 123000 miles.

The one on the middle at the top looks like a complete nightmare to replace or is there a way of doing it easily?

What is the general view on this subject?

Thanks

Steve

 
Title: Re: Idler pulleys
Post by: phoenix on 07 May 2013, 01:46:03 PM
They can go very noisy when they get worn, and you can hear them with the belt running. Prior to that, the only real way to know is if you spin the wheels without the belt on and check they run smoothly.

The top middle idler wheel was deleted after a while and there's an option of a shorter belt to fit the rest.
Title: Re: Idler pulleys
Post by: Steve440 on 07 May 2013, 03:58:40 PM
Yes they spin fine, I tried that before I fitted the new belt.

I was offered the shorter belt when I got the long one but I have read somewhere it can cause vibrations. Funny thing is the car is a lot smoother at idle now, maybe the old belt was causing  that?

Steve

Title: Re: Idler pulleys
Post by: TomPaine on 07 May 2013, 09:54:32 PM
I have always precautionarily had my idler replaced along with the drive belt at the latter's replacement intervals.

Re the short/long thing, Saabtech advised me when replacing the drive belt and idler last time around that they had had some issues fitting the short and had therefore gone back to recommending the long.
Title: Re: Idler pulleys
Post by: sgould on 08 May 2013, 08:18:24 AM
My 2007 9-5 has the shorter belt and missing idler.  On a couple of occasions, both in freezing weather, fully loaded, with all heating and lights on, I have smelt burning rubber.

I never pinned it down, but I suspect the belt was slipping a bit.  Probably one of the top pulleys as they are the ones with less belt contact with the shorter belt fitted.
Title: Re: Idler pulleys
Post by: phoenix on 08 May 2013, 10:32:22 AM
Belt slip will occur with the pulley that has highest load- that won't be an idler puller. The greatest load under those conditions is from the alternator which is at the bottom.
Title: Re: Idler pulleys
Post by: sgould on 08 May 2013, 04:20:42 PM
That's what I reckon too, which is one of the reasons I never got to the bottom of it all.