1998 Ford Ranger Loud whine

Remove fan belt, spin all pulleys that can be spun, Tensioner, Idler, A/C... one of them has a bad bearing in it, A/C pulleys are famous on fords... but tensioner and or idler with 340,000??? It's way over due! Ford compressors can be changer with a good junkyard pulley, and no freon loss to boot.

Finally was able to get to it. Removed the belt, the tensioner sounds rough and doesn't spins well, Idler, A/C, alternator seems fine. Get the part tonight.

Grab a new belt too!

Repleced the tensioner. After the old was removed it was grinding for sure. You could really feel and hear it well. This was needed but didn't fix the problem. An updated explanation. A loud whine when the engine is first started for the day or sat for long periods, IE. at work, and when leaving it will shortly quite usually when shifting into second and the power restored. Running great till it sits at light for extended time, IE. rush hour, or parked and inside the store for awhile. When leaving it starts the loud whine and power loss and may continue for all gears and for quite awhile down the road. Gets a lot louder as the trottle is pressed. Appears to be while the fan clutch is running. Again for this problem the following have been replaced and/or tested good. Tensioner, fan clutch (twice), power steering pump, water pump, IAC Valve (was very dirty and filled with grit), A/C condenser, and the belt. The problem seems to have cut back after the belt replaced. A guess but maybe due to more tension on the faulty parts. The A/C and Alternator pulley seemed to be OK. Not ruling these two out. But ot me why only when the fan clutch kicks in (seems to be when it does)? The Idler pulley was great, smooth and spun forever.

The IAC is a known part that causes hooting and whistling, also if there are cracks in the tube from the air filter to the throttle body, or loose clamps on same. Did you replace the IAC or just clean it? Ford recommends replacing and NOT cleaning.

I did replaced the IAC instead of cleaning. What about the MAF Senser?

I dont think the MAF would cause a whine unless it's leaking, then you would get codes for lean symptoms.
Is 340,000 the right mileage? If so, the clutch fan is probably no good, any oil stains on it?

Fan clutch was the first to get replaced, was even done twice. No oil stains on the fan clutch. 340,000 for the truck but had a rebuilt engine put in within the last year and the transmission was rebuilt about a month ago. This problem existed before the transmission work and thought it was part of that problem. All the parts listed have been replaced except for the Alternator and A/C compressor. The parts that have been replaced are Fan Clutch (twice), IAC Valve, Power Steering pump. A/C Condensor, Tensionor, water pump, and the belt.

I dont know if you can do this Joe, but if you can post a video while it makes the noise to you tube, then post a link here, it would help me hear and diagnose the sound?