So I have a 1990 Ranger XLT 4x4, 2.9 v6. My issue is I am getting a loud constant whistle sound on the drivers side, just in front of the rear tire. It is not from the tire and it is a whistle not a whine. The truck is all stock nothing special. I do not have an exhaust anymore only a cat. Anyways the sound is constant an does not get louder or quieter while moving or in neutral it just stays the same. It just started in the last few days. Also the truck is a Manual. Any ideas of what it could be would be helpful. Thank you!

 

Welcome to FTE.

Did the sound begin right after you removed the exhaust behind the cat converter????

Have someone drive, while you ride in the bed & listen to see which side the noise is coming from.

Why would you want to run it without a muffler or exhaust???? The engine is tuned to run with all the tubing in place & having the exhaust coming out the cat, under the cab, isn't safe.

 

My exhaust actually fell off one day while driving this was about 2 months ago the sound just started about 2 weeks ago. The sound is coming from the drivers side in front of the rear wheel. its not coming from the wheel at all or the wheel well. An the cat is on the passengers side. I plan on getting a new exhaust in the next few weeks when the funding for it comes in plus emissions is coming up so it is needed. But I ended up topping off my fluids. Did it one at a time to see if one would fix the problem and it stopped when I added some fluid into the clutch it stopped the last 2 days then came back. I"m guessing I have a leak that needs to be fixed.

 

OK, interesting feedback on the noise. Topping off the under hood clutch master cyl having an effect on the "loud constant whistle sound", that is in front of the drivers side rear wheel, is a new one on me!!!!! Topping off the clutch master cyl & having the wistle stop, might have been a coincidence, you know Murphys Law messing with your trouble shoot!!!! Might have been an echo of some sort. None of those parts are close to the drivers side rear wheel, or have vacuum lines attached that could make noise. Both the clutch master & slave cyl's & the interconnecting tubing belong on your leak suspect list.

On the noise, the only thing that comes to mind is maybe an axle bearing going bad, or low differential lube not lubing it, or maybe a dry drive shaft U joint.
More thoughts for consideration, let us know what you find.