When I first bought my 2007 Dakota V6 (used with 17000 KM) I noticed when I first started the truck in cold weather (-15C or less) I could hear a "grinding" noise. The noise would last less than five seconds.
This past fall, with about 170000 KM, I noticed a slight wining noise as the engine was started in cooler weather. (Not cold weather yet) The wining noise would go away after 5 to 10 minutes after the engine is warmed up. Now that it is winter, the grinding noise is back on really cold mornings again. The grinding noise last longer now. It increases in volume when the steering wheel is turned. Eventually after 10-15 minutes the noise more or less goes away, sometimes returning. It is more noticeable after warm up when turning the wheel when parking.
I tried spraying some lube on the pulleys but that was very temporary. I am leaning towards an issue with the power steering pulley. Any ideas/tips on how to diagnose where the sound is coming from? Is there a common failure on a specific pulley?

Thanks in advance.
Mark

 

The company I work for has about a dozen Dakotas ranging from 1999 to 2008 and I have found that changing the tensioner and belt usually cures this problem.

 

A mechanic's stethoscope should be able to narrow down which accessory is grinding. Just be careful and not touch any moving parts with it.

I did have to replace a grinding belt tensioner a few years back. The pulleys on it were fine, but the thin bushing between the two solid pieces wore down enough to allow them to rub against eachother.

If the sound gets momentarily louder while you are turning the wheel, the additional belt tension from the power steering pump load could be causing more noise from the tensioner being flexed further. Or it could be a failing power steering pump. Or a failing bearing in the pump pulley. Or none of the above. Or all of the above.

 

Thanks for all the replies. I'll take a closer look at the tensioner.
Mark

 

Oh, since it's been so long that I replaced the tensioner, I forgot to mention another symptom I had at the time: The grinding was worse when the A/C compressor was engaged. I almost mis-diagnosed it as a compressor/pulley issue, until I caught the tensioner out of the corner of my eye rocking to the same exact grinding pattern that I was hearing. The difference in belt tension upon compressor load was simply causing the tensioner to grind itself even harder when engaged.