1G 90 talon timing belt idler pulley

[Travis Grant]

Hey guys,
I'm having an issue finding a noise that's starting to to drive me crazy.

The noise is coming from the timing belt area. It's kind of a supercharger whine. I found some write ups about the same sound on 90's. Apparently it's due to straight cut gears in the oil pump.
Unfortunately I can't take someone else's word for it so I pulled the timing cover off to check for any odd behaviour from the pulleys.

Nothing seemed damaged or odd. Double checked tensioner plunger depth at 5/32. The engine has barely 50 Kms on it. I decided to start the vehicle and inspect for if the noise was more pronounced in a certain area and of course it's very loud by the oil pump gears. But I did notice that I could turn the TB idler pulley by hand. Is this normal. Tensions good in the belt. It's not easy to spin but it does with some force.
Thanks guys

 

[spyderdrifter]

Through my experience, being able to turn the pulley by hand in the way you're describing does seem to be normal. I've done it with mine even, and had a 91 6 bolt in my spyder.

 

[Vegas Smith]

You could have some rubbing from the belt onto the timing cover too.

 

[93AWDDSM]

My 92 does this sometimes. When I replaced the TB and everything I didn't do the TB idler pulley and guess what.. sure enough it started whining. When you ran it with the cover off could you distinguish where it was coming from or is it mainly by the oil pump? Did this noise just start? My buddy's 90 doesn't sound like that.