By Scott Kopiec (Skopiec) on Friday, October 26, 2001 - 11:06 am: Edit

OK, I need some help tracking this noise down. It's a relatively loud mid to high-pitched hum (not quite a squeal) that only happens when the Disco is warm and idling. If I touch the throttle, the noise disappears until the engine returns to idle.

I've sprayed water on the belt (fairly new) while it was making the noise - no change. I've also taken the serp. belt off and checked the pullies, and they all seem free without excessive play (W. Pump, S. Pump, etc).

Since it only happens at idle, could it be the IAC or something similar???

Any ideas?

Thanks !

Scott Kopiec
'96 SD

By Bill Bettridge (Billb) on Friday, October 26, 2001 - 01:03 pm: Edit

Could be the bearing in the idler (tensioner) pulley going bad - mine has been noisy for awhile and I just haven't done anything about it yet. Description of your noise could be other things, but sounds like mine. Try to squirt WD40 right onto the shaft/bearing from the back side of the idler pulley while engine is running. (DONT get any on the belt) - if noise stops - then you found it.

If that is the problem - below is how you fix it:


Contrary to what LRNA and RN tells you, you can replace just the bearing - it is available from NAPA (sorry, don't have p/n with me) - you need a 17mm wrench to remove the belt and then the idler pulley - remove the circlip holding the bearing in and then press it out - new one - press back in til it seats (be careful idler pulley is cast so cracks easily) - you're back in business.

By Scott Kopiec (Skopiec) on Friday, October 26, 2001 - 05:55 pm: Edit

No go -

I just went out in the parking lot with a can of WD-40. Sprayed the tensioner, and seemingly everything else, with no luck.

Any other suggestions?

Thanks!
Scott

By Scott Kopiec (Skopiec) on Saturday, October 27, 2001 - 11:59 am: Edit

Well I think I've tracked it down to the waterpump. No leaks, but my long screwdriver tells me it's the bearing. Strange how it only makes noise @ idle. No play in the shaft yet, any ideas on how long this thing might go before bad things happen?

Thanks,
Scott

By Tom Hogan (Tgh008) on Monday, November 19, 2001 - 09:10 am: Edit

I got the same problem. High pitch noise from the front end of the engine. Checked belts and no help. My 95 disco only overheats underload, such as pulling a light trailer. My problems only started after having my antifreeze flushed and replaced with new. (should have left well enough alone...) Help, any ideas before I start replacing waterpump and etc.