I've got a terrible whining sound that is intermittent coming from my '07 Grand Caravan. It doesn't do it when it is cold but after it warms up and I've been driving a while, it will start to whine from the engine bay. I notice it gets louder when I am turning my steering wheel. I checked my power steering fluid but it is still at full.

After a little reading on here, I see the power steering reservoir is a common culprit due to some sort of clogged screen. I also saw somebody saying there were 2 different color caps that go to 2 different part numbers. Mine is a black cap. Would a clogged reservoir be consistent or could be be intermittent based on how much driving is being done?

I also saw someone say to put it in park and see if the sound goes away (to rule out a tranny issue). It stays regardless so I guess I can be thankful for that.

I just want to track this down. It really sounds a lot like a worn pump on its last leg. I hope that isn't the case since our van only has 47,000 miles on it.

 

Lucas Power steering treatment works wonders
for the 5-6 bucks its worth I try in on all noisy PS pumps before I delve into them

 

If it's the reservoir, you'll notice the whining more on cold starts. That's because the gunk in the PS fluid has settled on the filter screen at the bottom. Once it heats up, the hot fluid breaks up the crud on the screen and the pump can suck fluid more easily. So if it seems better when warm, it's usually the reservoir.

It's a pretty easy and inexpensive job to replace it. Why not start with the least expensive part first?

 

Actually, it the screen is plugging, they usually make noise warm and not cold. Noise cold is almost always low fluid.

 

So I'm a tad confused here due to conflicting information. RickMN says I should notice it more on cold starts but Tizzy1 says I should notice it more as it gets warmer. Obviously, it can't be both. Any clarification on this one?

As for a little more info, while it gets VERY noticeable once I have been driving it for a while, it is still semi-noticeable at first start. I have to do a 3 point turn to get out of my neighborhood. Upon each turn of the wheel, I can hear the whining albeit not quite as loud as when it has been going for a while.

 

Well, I disagree with Tizzy. The reason it whines more at cold is that all the varnish settles on the filter screen at the bottom of the reservoir. So the pump gets starved for fluid. Then, as it heats up, it flushes the crud off the screen and it just circulates around the reservoir. Look at the reservoir cut-away in my post below and you'll see where the screen is. And you'll see where the return line comes in. You can see that it's located down near the screen. The hot return fluid creates the swirl that dislodges the crud---until it cools and resettles.

But hey, if Tizzy is correct and you have low fluid, that's easy enough to check out and fix.

Here's the post:

http://www.ricksfreeautorepairadvice...ysler-vehicles

 

Thanks for the reply, Rick. I definitely don't have low fluid. It is right at the full line. Due to the fact that it gets much worse as the van heats up, it makes me doubt it is the reservoir. On cold start, it only makes the sound when you turn the wheel all the way in one direction. However, as it heats up, it gets much louder. You can even hear it when just doing normal driving and slight turns. I'm assuming, if it were the pump itself, it would be consistent and the way it is now, the reservoir doesn't quite appear to be the culprit either. Would you recommend replacing it anyway or does it seem to be something else based on the symptoms. While the reservoir isn't that expensive, it is more cash than I really want to throw away if it isn't the likely culprit.

 

use the lucas and it will shut right up
is 6 bucks too much to throw away?

suck some fluid out of resivoir the replace with Lucas PS treatment, turn lock to lock a handfull of times to get it moving around in the system.

 

I had much the same situation on my '04 as you. I first thought it was the trans. I replaced the power steering reservoir at about 65k miles and solved my problem. An easy and not expensive fix. Use a turkey baster to remove the fluid from the reservoir, place an old rag around the reservoir to catch the drips. This is a good time to refresh the fluid in the system.

 

I think I'll try the Lucas first...if I can find some at my local auto store. I'm assuming any brand will do the trick if I can't find any correct? If that fails to do the trick, I guess I'll just try the reservoir. Should be easy enough either way. I figure if I can pull, tear down, and rebuild the motor in my twin turbo 300ZX, I can do this. lol