Engine Moaning

[fngearhead]

My '91 L is making a strange moaning noise. Its been going on for a while, but until yesterday, it was very erratic. It would only do it at specific revs. Yesterday, it decided to do it continuously at idle and I can't make it stop. It only goes away as the revs climb up above 2k or so. I pulled the airbox and tube, disc. and reconnected the MAF. I even rigged the MAF straight to the throttle body and ran it for a few seconds to rule out the airtube. This car has been running without a snorkus for over a year and the moaning just started about 2 months ago. The only non-stock part of the intake system is a K&N drop in. Any ideas? Its only been one day and its getting pretty annoying already.

[BAC5.2]

Describe the noise a bit more.

Does it sound like a tire rubbing on plastic?

Might be the timing belt idler gone kaput.

[fngearhead]

I really hope that's not the case. I just had the T-belt done in Oct and the shop supposedly replaced the idler. The noise sounds kind of like when you blow just right across the top of a beer bottle.

[93forestpearl]

Power steering pump?

[fngearhead]

The noise got louder when the airtube was disconnected. This makes me think its coming from inside the engine somehow.

[fngearhead]

So the mystery noise has ceased. But now my idle is all over the place. Sometimes its normal - around 1000, but then at the next stop sign, its up to 2000. From what I've searched and read on here, I'm thinking its time to look at the IAC.

[sammydafish]

the hose is off of your idle air control valve, or maybe a PCV hose is off. Will make the car run like poop and make exactly that "blow over a bottle" noise.