I have a 2001 Dakota 4x4 3.9 V6 5speed 68K miles.

I've had this problem for awhile now. There is an annoying whining noise coming from the engine at idle level RPMs (under 1k). It stops as soon as I tap the gas. It does it whether its in gear or not. It wouldn't happen everyday though. So of course when I took it to the dealerit didn'tdo it. I've noticed it more these past few days, so I'm thinking it may have something to do with the cold weather (the winter has finally arrived in upstate NY). It seems to tame down when the engine is fully warmed up, but it doesn't go away completely. I've popped the hood while it was making the noise, but I was unable to tell where it was coming from.

Any ideas? Anything I should do that would help me diagnose it better?

I've had this truck for under a year and haven't done anything to it besides the usual oil changes, so i'm def a dakota novice.

 

you might want to check for slack in your drive belt. There should be about half an inch. It could be a pulley that is starting to go. You could take your belt off and spin the pulleys, they should all spin super smooth. Any noise at all and it should be replaced. Its almost imposible to tell where a noise is comming from by listening to it because there are so many moving parts. I just replaced my fan clutch and idler pulley because they were making noise. If it doesnt do it that often then i wouldnt worry about it.

 

Yeah, its most likely coming from that area. Either the belt, or one of the pulleys its turning.. check them each individually.

Heres a way to pinpoint where tthe noise is coming from. Take a small (3 feetish) piece of garden hose. Turn your truck on so the engine is making the whining noise. Now, hold one end of the hose up to your ear. Then put the other end of the hose up to different areas under the hood. You'll defintely be able to hear the difference when you find whre the noise is coming from. Once youv pinpointed th problem, post another thread and we can help ya fix it

Edit: Oh yeah, and be careful not to get the hose snagged in any moving parts under the hood. Id recommend wearing goggles just in case

 

thats a great idea!!! (hits forehead)never heard of it but man i could have used the idea before!!

 

Yeah, my uncle was a mechanic for 10 years.. thats one of the many little tricks he's showed me

 

i like that idea too

 

The truck is going into the dealer for an inspection tomorrow so I'm hoping they can pinpoint the issue and fix it. If not, then I will def try the hose idea.

Thanks for the help so far. I will keep you guys posted on what happens

 

The dealer said that my serpentine belt was worn and pretty glossy. they replaced that and I haven't heard the whine since then. So i guess the problem is all fixed.


no wonder I couldn't pinpoint where the whine was coming from.

 

I had the same problem. After replacing the belt, haven't heard it since. Also, using a garden hose is a great idea, but using a very long screwdriver to pinpoint internal sounds is the way to go. Put the working end of the screwdriver on suspected areas and the handle to your ear. This allows you to check for knocks or head issues.

 

i have to agree, i love that trick. put your thumb over your inner ear lobe and press the screwdriver against your thumb.