Question about 2003 Toyota Prius

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Coolant Pump Noise after engine off

After turning engine off in cooler weather there is a reservoir pump noise. How easy is it to replace it myself?

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  • Anonymous Jan 26, 2009

    I have the same problem and have had the pump replaced once already, however the noise persists. Toyota claims that this will not effect the opeation of the car and will not leave me stranded. I have friends with Priuses and their cars do not make this noise. This is my second Prius and both cars have done the same thing. Does Toyota really know the cause of this noise???

  • Toyota Ed May 11, 2010

    You do not need to replace it, and it is difficult to replace, as you will not be able to bleed the air out without a scan tool; you run the risk of overheating and damaging the inverter. The noise that you are hearing is the "heated coolant storage system" operating. This is a normal condition, and is to be expected in cooler weather. Under the driver side front fender is a big "thermos bottle", that holds hot coolant, your car is normal, unless you have malfucntion lights on. Please feel free to post back if you have any other concerns.



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Here's the Toyota TSB that describes the problem and directs the dealership what to do about it:

Posted on Jan 25, 2009


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Power steering making noise

The power steering will make a noise if insufficient oil is in the system. After replacing the pump, it is no good just topping up the reservoir, the system needs to be purged. It is best to do this with the front wheels off the ground. Fill the reservoir and then, with the engine running, turn the wheel from lock to lock ( fully one way then fully the other way). Do this a number of times and keep topping up the reservoir to the correct level. With the bonnet, (Hood), up you should be able to hear where the noise is coming from. If the system has been properly serviced it should be quiet. If not you might have to get another pump.

Aug 05, 2015 | 2000 Bentley Arnage


Power Steering Pump Noise

As you turn your steering wheel it is this fluid pressure that aids in turning the wheels of your car. ... If the pump impeller is trying to move power steering fluid and starts catching air bubbles it can cause whining noises and vibrations to occur.
Maybe you've heard it at a stop light. Maybe you've heard it as you pass a car on the freeway. Or maybe you've heard it in the parking lot at work when someone is leaving. The unmistakable whine of a power steering pump can make even the most confident mechanic wonder when that car will breakdown.
Power steering pump noise is a unique noise that your car may make and once you've heard it you always know what it is. The noise is a mix of a whirring and a whining and will always vary with the speed of your engine whether your car is driving or in park. This whining noise can be subtle or extremely loud and may be worse in colder weather, or right when you first start your car.
Power steering pumps are most often vain style centrifugal pumps that are tasked with pressurizing the power steering fluid and pushing it down to your power steering gear or rack. As you turn your steering wheel it is this fluid pressure that aids in turning the wheels of your car.
There are a few reasons why you are hearing power steering pump noise from your car. First, it may simply be due to the design of the pump. Sometimes, noisy power steering pumps can continue to work flawlessly for years after they start making noise. This may simply be due to the manufacture's design or a tight tolerance in that particular pump. In this case, you would hear the noise but not see any other adverse effect like a loss in power steering, leaking fluid or a wobbly pulley. In this case, you may be able to help reduce your power steering pump noise by choosing a different type of power steering fluid, like a synthetic fluid.
Your power steering pump may also be making noises due to air trapped in the system. If the pump impeller is trying to move power steering fluid and starts catching air bubbles it can cause whining noises and vibrations to occur. Even tiny air bubbles you cannot see that are trapping in the power steering fluid may be causing the whining you are hearing. In this case, the best thing to do is flush your power steering system to try and remove the air from the system. Having air trapped in your power steering system can be difficult to diagnose so you may need to simply try a power steering flush to see if it solves your problem.
Power Steering pump noise may also be due to a failing power steering pump. As the bearings on the impeller go bad it will start to make noise as the pump is turning. If you have a bad power steering pump you usually will also experience leaks from around the pulley, a wobbly pulley, or difficulty turning the steering wheel when you are stopped. If you have multiple of these symptoms together, it is probably time to replace your power steering pump.
Lastly, and most usually, a whining power steering pump is an indication of a low fluid level. Your power steering fluid is probably something you have rarely if ever checked, so it often comes as a surprise if the level is low. Your power steering fluid reservoir is also relatively small so even a slow leak will cause a low fluid level relatively quickly. To confirm this is your problem it is as simple as checking your power steering fluid level. Some power steering reservoirs are clear so you can see through them to check how full they are. You may have to wipe away some dirt and grime to find the "full" line, but it should be easy to check. If you have an opaque power steering fluid reservoir there should be a small dipstick under the cap that will help you measure the fluid level. If it is low, then you have a leak somewhere and topping off the fluid should quite down your power steering pump.
If you discover a power steering leak, rather than simply continuing to add fluid every time it gets low, you should fix the problem permanently so you don't have to continue to check your power steering fluid level. Replacing lines or seals can be a surprisingly difficult task due to the location of your power steering pump and steering gear or rack. The easiest way to seal your leak is to do it from the inside out!

try this link out for more power steering problems.
Power steering whining sqreeching Google Search

on Dec 14, 2017 | Cars & Trucks

1 Answer

How to bleed the power steering pump?

Probably too late now, but with new pump, jack up front end and put on stands. Fill reservoir to normal full, start engine and slowly turn wheel right and then left to almost lock. Refill as needed and repeat until all bubble disappear from reservoir. Still got noise? Replace pump.

Feb 22, 2015 | 2003 Buick Century

1 Answer

Ford Taurus over heating, rust in reservoir , squealing noise, orange fluid leaking, bad smell

Your water pump has broken down the seal has worn and let the water out seizing up pully the squeling noise is drive belt sliping as engin trys to turn pump replacement soon as,..... if u use it u will blow engine up

Oct 06, 2013 | 2004 Ford Taurus

1 Answer

Having trouble with power steering pump. I think it has to do with the fluid/leak fixer I put in. I have been given some small amount of hope that if I drain the system and put the correct fluid in it I...

Hello, since you have a Limited it probably has an oil cooler at the bottom front of the vehicle. They are usually hung ahead of the radiator.

The oil cooler is a good access point because it is the lowest point of the system. One of your lines will come from your Reservoir and the other will go to the pump. Check the Reservoir line for leaks as the plastic clips hold moisture and corrode the metal portion of the line. These small air leaks will reduce the efficiency of your pump.

Unless Ford makes a product to clean the pump, I would use the correct fluid and let the pump cycle the fluid out 1 quart at a time. Drain the Reservoir first, let the pump side drain out the cooler line, reconnect, add 1 quart, run vehicle, drain Reservoir, drain pump line, repeat. Probably waste 3 quarts of fresh fluid doing this, 1 quart at a time.

Now I understand if noise is the problem, Lube-guard makes about 8 products and the one for Power steering will reduce noise almost immediately. I have heard it work on a 2004 F150. There are also Quick lube places with pumps for Transmission fluid changes. If you want to try their system, I believe they can use adapters and hook you up.

Jan 20, 2011 | 2007 Ford Freestyle Limited

1 Answer

How to replace a radiator on a1994 toyota land cruiser


  1. Disconnect battery ground cable.
  2. Drain engine coolant.
  3. Remove battery and tray,
  4. Remove radiator grille
  5. Disconnect No. 3 water bypass hose.
  6. Disconnect radiator inlet hose.
  7. Disconnect coolant reservoir hose.
  8. Loosen water pump pulley mounting bolts.
  9. Loosen lock, pivot and adjusting bolts of alternator and remove drive belts.
  10. Disconnect oil cooler hose from clamp on fan shroud, then remove shroud.
  11. Remove water pump pulley mounting nuts.
  12. Remove fan with fluid coupling, water pump pulley and fan shroud.
  13. Disconnect transmission oil cooler hoses.
  14. Disconnect radiator outlet hose.
  15. Remove radiator brackets, then the radiator.
  16. Reverse procedure to install.

Dec 11, 2010 | 1994 Toyota Land Cruiser

3 Answers

Power steering hard and noisey

Hi Maldon,

I haven't heard the noise, but it's usually the belt. Check its tension, check it for frays or wear.

No filter. If the pump it going out, the reservoir and pump are a single unit and need to be replaced as such.

Best regards


Oct 08, 2009 | 2006 Dodge Ram 1500

2 Answers

No interior heat / engine overheated 97 dodge ram 1500

From your description i would say the thermostat stuck closed, no heat, running hot, boiling in resavor, thermostat bad, replace. must of got real hot to makes that kind of clunking noise, I just hope for your sake thats all it is, of course i don't know the history of the truck, but right now it sounds like thermostat. There is an outside chance it could be a head gasget, cracked head, pluged radiator, thies are all worst case sanareo.

Feb 17, 2009 | 1997 Dodge Ram 1500 Club Cab

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