1999 Infiniti Q45 • V8 2WD Automatic • 190,000 miles

What would cause immediate loss of power steering? I was driving on the highway last night and heard a loud sound, like I hit a rock. I experienced immediate loss of power steering. No lights came on, and the car drove "fine" expect there was no power steering. I looked this morning and all the belts appear to be there expect one of them isnt moving.
July 3, 2011.

I sorta think you found the clue. A belt that isn't turning is pretty obvious something is wrong. It probably came off the crankshaft pulley on the bottom of the engine or it has snapped and must be replaced.

Jul 3, 2011.
Well, that sounds a lot better than I imagined the problem to be. I sure hope that is the only problem. Do you think the car is drivable, short distance to and from work tomorrow, until Tuesday when I can get it into the shop?

Jul 3, 2011.
From everything I looked at, it appears your car uses at least three separate belts and possibly a fourth one. That means the water pump will still be cooling the engine, the generator will still be charging the battery, and the air conditioning compressor will still run. Only the power steering will be dead.

Before you start the engine, try to pull that belt completely out so it doesn't get tangled in the other belts and cause one of them to fall off. If you get it out, it should be okay to drive. You won't notice the lack of power assist on the highway, but the slower you go the harder it will be to turn the steering. You won't want to be sucking on an ice cream cone with one hand and driving with the other one in slow traffic!

It is also common for power steering fluid to get pushed out of the reservoir when you turn the steering without the pump running, so don't panic if you see a fluid leak where you park. Once the new belt is installed, the fluid will need to be topped off, and if air got pulled into the steering gear, you might hear some buzzing for a while. It will be worse when turning the steering wheel. The more you turn the wheels, the more air will be purged, and you might have to add a little more fluid a few days later.

It is also entirely possible no fluid will be pushed out and a new belt will be all that's necessary.

Jul 4, 2011.