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sprinkles08, ASE Certified Technician
Category: Jeep
Satisfied Customers: 22976
Experience:  Chrysler/Dodge/Jeep Master Certified, ASE Master and Advanced Certified, Trans and Hybrid Specialist
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Grand Cherokee: I have a 2003 Jeep Grand Cherokee v8. When

Customer Question

I have a 2003 Jeep Grand Cherokee v8. When the a/c is on, I get a whining noise from the power steering pump. (Especially when turning right and especially when approaching the turn limits-it is pretty quiet when driving in a straight line.) When the a/c is off, the pump is quiet. I changed the pump and the noise is still there. The fluid is at the proper level. The belt is in good shape. The water pump and a/c compressor are good. There is no play in the steering wheel. Could my steering gear be going bad? Apparently, the added power drain of the a/c clutch engaging causes a power reduction in the pump. Maybe the pump is being overworked by a worn steering gear. The steering gear on the jeep is the original. The jeep has 143k miles on it.
Submitted: 2 years ago.
Category: Jeep
Expert:  Brad replied 2 years ago.
It sounds like you need to replace the pump and flush the system with new fluid...
Customer: replied 2 years ago.
I changed it
Expert:  Brad replied 2 years ago.
Was it a OEM pump or aftermarket?
Customer: replied 2 years ago.
the one that was on the car was a new one from NAPA. The one I replaced it with is a remanufactured one. The vehicle has the same symptoms with the new pump as the napa pump, which was done by a jeep mechanic. All of the hoses were changed then, too. This was February of 2014. New pump, new hoses by jeep mechanic. I changed the pump last week using the remanufactured. Do you think a worn steering gear can put extra strain on the pump? Or if there is no play in the steering, would you say the steering gear is good?
Expert:  sprinkles08 replied 2 years ago.
Hello and welcome to JustAnswer!
I doubt there is an issue in the steering gear. Most power steering noises are caused by the pump itself assuming the fluid is full and a Napa pump is almost guaranteed to cause noise out of the box, but I'm wondering if you have a hydraulic cooling fan. The hydraulic cooling fan was an option with the 4.7 and that would explain why it makes noise with the a/c on.
Do you have a hydraulic fan?
Is the fluid aerating?
Customer: replied 2 years ago.
Yes, I have a hydraulic fan. Not sure how to tell if fluid is aerating. I don't see any air bubbles in the power steering reservoir. That Napa pump worked fine for just over a year. And the new pump I put on did not correct the issue. That's what confuses me. I had a leak on the original pump that came on the new car in 2003. I think that got changed through warranty (maybe in 2005). That one then went bad and the jeep mechanic changed it in Feb of 2014 with new lines. The car started making a humming/vibration feel and a noise/vibration when turning (which I identify as the power steering because I have been through this before and it sounds and feels like that problem) and then the water pump went out (started leaking) and the a/c went out, too (ac had been getting bad over the years). So the water pump, ac compressor and dryer were changed. The jeep still made the sound/vibration when turning the wheel, so I put a new pump on. I am lost now. The radiator was changed, too, about 1 to three years ago at a jeep dealership. It got a hole and started leaking.
Expert:  sprinkles08 replied 2 years ago.
If the lines have been ruled out and the fluid isn't aerating then the problem is either the pump or the hydraulic fan assembly. It's highly unlikely that the fan assembly is causing the issue an it's about a $1,500 repair. Aftermarket power steering pumps have shown atrocious quality over the past 6-8 years and I've found they're guaranteed to fail. I've personally had numerous vehicles that have had 4-5 aftermarket pumps each before spending a little more on a Mopar pump and repairing the issue, others in the shop have had the same issues, and I see it happening with customer on this site regularly. I would recommend replacing the pump with a Mopar part and it should take care of the issue.
Customer: replied 2 years ago.
Thanks! Can you buy the mopar pumps with a pulley attached already. That was a bear screwing down the one I put in. We put a bolt in the hole in the middle of the shaft and then screwed down a nut with washers between the pulley and the nut to get it onto the shaft, and it sucked!
Customer: replied 2 years ago.
Do I have to buy the mopar pump from a jeep dealer?
Expert:  sprinkles08 replied 2 years ago.
The pulley will need to be swapped either way. A power steering pump pulley installer should be used to remove and install the pulley. If you don't have one available you can usually borrow or rent one from a big chain parts store such as Autozone.
A Mopar pump would either need to come from a dealer or from an online Mopar parts wholesale site such as,, etc.