Grinding noise.

My Tacoma makes a grinding noise when I turn to the left and when I go straight. Stops when I turn the wheel to the right. Only does it at slow speeds and can’t hear it after driving for awhile, except if I hit a bump, then I hear it for a split second. At first it only did it while moving, so I initially thought it was a bad bearing, but now it’s doing it while stopped. I took it to the dealer and just so happens it wouldn’t make the noise anymore. They had it for 4 days, couldn’t recreate the noise. And it doesn’t do it everyday, and only noticeable when the engine is cold. Can’t notice it after driving it for awhile. Maybe bad engine or transmission mounts?

2008 2wd 4dr pre runner V6 stock

 

How's your power steering fluid level? And if any has recently been added, was it the correct type? Might also be the power steering hoses getting hard and brittle; that can cause pulsing/vibration.

 

When I took it to dealer, they said I needed new rack and pinion and replaced all power steering hoses and also replaced front right wheel bearing.

 

If they didn’t resolve your original complaint I would take it back and make them fix it. Did they tell you that what they did would take care of it?

 

I wonder if the pump itself is bad. How many miles on this vehicle?

 

Yup, possibly the pump or a clogged screen in the reservoir.

 

Dealer said that may not be what’s causing it, just said that rack and pinion was in bad shape and was leaking power steering fluid. Right wheel bearing was just staring to show signs of failure so I told them to go ahead and replace it. But if it was the power steering pump, wouldn’t there be more of a whine rather than a grinding noise? And I will clarify, it sounds like metal on metal. And about 160,000 miles

 

Hm... Metal on metal... Possible the pump bearings are shot? Dry bearing noise can sometimes be intermittent.

Does the steering FEEL okay, I mean forgetting the noise for the time being?

I was going to suggest the possibility of a bad PS pressure sensor as well. They're typically less than $30 and not that hard to swap out, as long as fluid hasn't leaked back into the wiring. But I have to admit this is getting above my pay grade. I'll let the people take over who know 100x more about these trucks than I ever will.

 

Check the brake dust shield on the rotors, make sure they aren't rubbing then check all of the heat shields under the truck to see if they are vibrating/loose.

 

Steering seems fine, and I haven’t had to add any power steering fluid. I’ve had power steering issues before in other vehicles, which was always accompanied by a whining noise no matter the direction that I turned the wheel. If it made the grinding noise turning both left AND right, then I would suspect power steering, but as soon as turn the steering wheel to the right from straight ahead, the noise stops.

 

> I’ve had power steering issues before in other vehicles [...]

Then, could this be user error? Back in the day, when power steering first became widely available (yeah I'm old), a pump could be destroyed in short order by holding the steering wheel at full lock. It would create a drastic over-pressure condition. I don't know if this is still the case, i.e. with modern pumps. So, have you (or someone else who drives the vehicle) been doing this?

EDIT: I suppose it's possible the new rack is defective. Or there were metal shavings in the fluid before the swap, but the system wasn't purged out first. I'd be wary of doing a rack swap without doing a total system flush, and maybe even adding an inline filter if possible.