Greetings all - have an '05 Pathfinder w/ 93k miles. Recently noticed a uneven feel in the power steering, most noticeable at slower (less than 30mph) speeds. Feels like the power steering pump is intermittently engaging/disengaging. As I turn the steering wheel I feel random “tight” or “hard” spots in the steering. Similar to what you would feel if the wheel was against a curb and you were trying to turn into it. Doesn’t make any appreciable noise, but can just feel it in the steering wheel.
Checked power steering fluid, no issue. Replaced power steering pump, had no effect. Power-flushed the power steering system, had no effect.
Oh - and my wife says she hasn’t hit any large rocks, logs, or potholes recently!
Any ideas? Thanks!
Take a look at the power steering pressure switch.
This switch sends a signal to the computer and the computer commands the Idle Air Control valve to bump the idle up for the load the power steering pump imposes on the engine. If the this switch fails to inform the computer the pressure is increasing, the power steering pump slows down and doesn’t provide power steering assist.
Tester
Thanks Tester.
After reading your comment I started the car and, with the engine at idle speed, moved the steering wheel back and forth. I definitely get some RPM movement by rotating the steering wheel, which tells me (I think) that the power steering pressure switch is working. I also rev’ed the engine to 2,000 RPM and tried the steering again. The tightness or binding seemed to diminish a bit, but was very noticeably still present. In the tightest of the tight spots I even get a bit of steering wheel shudder (w/ vehicle sitting stationary) as I push through the tight spot and continue rotating the steering wheel.
Any other thoughts? Thanks!
Then what you’re feeling might be hard spots in the rack assembly.
You might give this a try.
And follow the directions on the bottle.
The vehicle is ten years old. And if you’ve never changed the power steering fluid, it could be the problem.
Tester
Again - thank you Tester.
The fluid in the car now is brand new (just had it flushed at the Nissan dealership this morning), but that doesn’t necessarily mean there isn’t “residue” left behind from the old stuff (which I’m pretty sure was the factory-installed fluid).
For $10, the Lucas stuff is certainly worth a try. I’ll get some in there and report back.
Bought a 32oz bottle of the Lucas Power Steering fluid. I drained the power steering reservoir using a suction tube and re-filled w/ the Lucas stuff, then ran the engine and cycled the steering back and forth until the new fluid was pumped through and mixed. I repeated this two more times and figure I ended up with about a 30%/70% mix of Lucas to standard fluid, respectively.
I drove the car around the block a few times and it seems to be helping. I may be getting fooled by the fact that the roads are covered in snow/ice tonight (less force required to turn the wheels), but I’ll drive it this way for a week or so and see if the kinks work themselves out.