Power steering goes out.

[Vortec]

My stepson has a 2003 vibe gt. It runs fine but then loses power steering after a few miles. It seems the only time it goes out is when the ac is on. This leads me to suspect that the belt tensioner might be failing and when the extra load of the compressor is applied, it allows the belt to slip. Any other thoughts? I'm really hoping to avoid having to tear into the steering system itself.

Thanks

[SSizler]

Sounds reasonable.
All 3 of the Vibes I've owned have needed a tensioner.
I never had a power steering problem, but none of mine we GT's either, all 1zz.
Can you duplicate it in the driveway and watch the belt / pulleys?

[Vortec]

We ran it in the driveway at idle and at various RPMs and I watched the belt and pulleys while he turned the wheel lock-to-lock. We couldn't replicate the problem except when driving and nothing looked or sounded wrong.

[jolt]

I was driving the Vibe, when the engine died, and it did not effect the power steering at all. My other car had the engine stall and it was all hands on the wheel trying to get it steered over to the side of the road. That is a nice thing about the electric power steering and a safe thing, too.

The Air Conditioning load and belt slipping is not going to effect the power steering. Most new cars have a slip clutch built into the pulley for the alternator and these can go bad. They will start to squeal and make noise when accelerating. I do not know for sure but I would check to see if the steering electric motor has brushes and if the brushes are worn out. This is common in DC electric motors. Wire connections?

[joatmon]

I do not know for sure but I would check to see if the steering electric motor has brushes and if the brushes are worn out. This is common in DC electric motors. Wire connections?

The afflicted Vibe is an 03 GT, which has a belt driven hydraulic power steering pump, there's nothing electrical about it.

The 03 Matrix manual lists these potential causes for hard steering

Code: Select all

1. Tires (Improperly inflated)
2. Power steering fluid level (Low)
3. Drive belt (Loose)
4. Front wheel alignment (Incorrect)
5. Steering system joints (Worn)
6. Suspension arm ball joints (Worn)
7. Steering column (Binding)
8. Power steering vane pump
9. Power steering gear

seems like the only one of those affected by the AC would be the belt, but since the tests couldn't recreate a slipping belt, I don't have anything else to offer

[jolt]

Yes, joatmon, I don't know how I missed that. Only the '09 and '10 have electric power steering. Old age is getting to me.

I guess I would be leaning more toward the pump or rack being the problem, but not being there I could not say. With the steering all the way to it's end of travel is when the pump is working it's hardest. On most cars you will hear the pump drive belt squeal if you keep pulling on the steering wheel when it is at it's end of travel. The squeal is the pump belt slipping because of the increased pump load. It could be an indicator and something to think about in troubleshooting this issue before you get into pump pressure readings.

[Vortec]

Never any squeaking and we didn't actually see the belt slip.

What we've tried so far:
-New belt - not much change.
-New belt tensioner - ran great for about 5 miles, then started slipping.
-Replaced old battery that was slow starting and not holding full charge, even from a trickle charger. BIG improvement which lasted for about 30 minutes, then the problem returned.
We pulled the car into the driveway and watched the belt and pulleys while my wife steered. After several minutes we finally saw the pulleys and belt slow intermittently.

I'm probably going to tow it over to our house in a few days so I can have proper workspace and my tools so I can properly dig into it instead of driving into town when work and weather permit. Idk how long it may have been gradually starting to do this because he only mentioned it once it caused a significant problem.

[joatmon]

Tensioner is supposed to be a pain on the GT

With a new belt and tensioner and still slipping, you could try taking the belt off and lightly sanding the drive pulley (crankshaft) in case it is glazed over. Something to increase the friction between the drive pulley and the new belt. Might not help, but couldn't hurt

[Vortec]

Tensioner is supposed to be a pain on the GT

lightly sanding the drive pulley (crankshaft) in case it is glazed over.

Tensioner wasn't too difficult. Though I just replaced the piston part of it since the arm and pulley were fine.

I will definitely sand the crank pulley, and probably the others, once I get it to my place. Using belt dressing did help temporarily.

[Vortec]

Apparently my stepson put power steering fluid in the reservoir a few months ago instead of ATF. In fairness, the cap on the reservoir does say "power steering fluid" in big letters and only mentions ATF in the fine print. I really don't know if it did any damage but we flushed the system and refilled with ATF just in case. The PSF was definitely higher viscosity than the ATF so I am concerned that it wasn't flowing everywhere it needed to at proper pressures.

After the flush, the steering was better but still not like it should be, and I can still see the belt slipping.