I have an ongoing a presistant squel while sitting at idle. AFter starting the vehicle almost immediately a squeal will appear, once I begin accelerating it appears not to be present or apperant. It does not increase with the speed of the belt under acceleration.

I have attempted to isolate the best that I can. Removed drive belt and checked idler pulley and tensioner (tensioner has slight play, but does not seem to alarming). A/C clutch is not frozen. Alternator is charging battery.

Replaced timing belt and all associated pulleys about 75-80k miles ago.

I have taking the cover off the timing belt housing in attempt to locate the squeal to no avail. When attempting to locate the source, the origin seems to blend its location with all the other moving parts.

Could it be the a/c clutch, alternator (which I now believe are my to primary sources) or could it be the timing belt tensioner prematurely wearing out.

I know it is near impossible to diagnose the source of a noise through a forum but any insight may help.

Thanks

 

Did you give everything a spin when you had the belt off? If it makes noise or feel roughness when you turn pulleys then you may have a bum bearing. If nothing in the accessory circuit, then you could check the idler and tensioner on the timing belt. Try a length of hose used as a stethoscope with the engine idling.
Ed

 

had this on my t4 about a week ago it was the alternator i replaced it with one from the scrapyard cost £30 can be changed on a s40 v40 in about 40mins a t4 takes much longer cuz not much room to get it out

 

Ah yes, some of the alternators have clutched or overrunning pulleys that can fail. A new pulley may cost more than a salvage alternator.
Ed