My wife has a 2003 T4R Limited, 4.8L, 201k miles, and it has started making a loud whine upon start up the past couple months (as it's gotten cold). Sounds definitely like the power steering pump, and the pitch changes as you turn the wheel lock to lock, so I'm sure its something related to the power steering. My question is, is the power steering pulley or bearing notorious or anything for making noise when they are going out? I was going to flush the power steering fluid this week and refill with synthetic and see if that helps at all, but figured I'd see if anyone else has dealt with this and had it be anything else. I'm pretty sure it's not a belt, and the noise goes away after the truck's been driven for about 5 minutes and started to get warm. I'd almost chalk it up to it just being cold, but we've had it for about 8 or 9 winters now and never had an issue. I've also got an '04 T4R 4.0L and get no sound at all from my power steering when started in the same conditions. Thanks for any advice!
2003 4.8L, Power Steering Noise when cold.....
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Inv4drZm
Senior Member
Mine's been whining only on startup for a minute or two as well, but that was since I did the PS flush a month ago, but maybe the cold weather has something to do with it. I thought it would work itself out by now and I'm not sure how to bleed the air out if that is even the problem.
It's ATF fluid that goes back in, not power steering fluid?? I hadn't checked the manual yet or read the fine print on the reservoir lid yet, but just assumed it took traditional power steering fluid.
First, make sure your fluid level is full. Whine can be caused by low fluid level.
If it's not that, it's probably a bypass valve or flow control valve that is sticking more than usual when it's cold. The bypass valve provides a path for the fluid to go when it's not being needed for moving the steering gear. The pump is always providing more fluid than necessary, so some is always going through the bypass valve. The amount changes with engine speed and steering load.
If the valve is sticky, there will be pressure pulses in the system (pressure builds up and the valve opens, causing the pressure to drop and the valve recloses, etc.), and you will hear those pulses as a whining noise proportional to pump speed. The colder the oil, the more sticking, so the louder the whining. (If you listen closely to a new, warmed up pump, you'll hear the same whining, just not nearly as loud.)
If it annoys or concerns you, the fix is probably a new or rebuilt pump, which is where the flow control valve lives. However, it can behave this way for years without any other failure symptoms, so I'd be inclined to just live with it. I've been around hydraulic systems all my life, from the time I grew up on the farm, and whining, especially in cold weather, is pretty much an expected thing. I don't know of anyone ever thinking twice about it. In fact, if you spend any time around commercial hydraulics (tow truck winches, cranes, front-end loaders) and listen, you'll hear the hydraulics whining whenever they're used.
If it's not that, it's probably a bypass valve or flow control valve that is sticking more than usual when it's cold. The bypass valve provides a path for the fluid to go when it's not being needed for moving the steering gear. The pump is always providing more fluid than necessary, so some is always going through the bypass valve. The amount changes with engine speed and steering load.
If the valve is sticky, there will be pressure pulses in the system (pressure builds up and the valve opens, causing the pressure to drop and the valve recloses, etc.), and you will hear those pulses as a whining noise proportional to pump speed. The colder the oil, the more sticking, so the louder the whining. (If you listen closely to a new, warmed up pump, you'll hear the same whining, just not nearly as loud.)
If it annoys or concerns you, the fix is probably a new or rebuilt pump, which is where the flow control valve lives. However, it can behave this way for years without any other failure symptoms, so I'd be inclined to just live with it. I've been around hydraulic systems all my life, from the time I grew up on the farm, and whining, especially in cold weather, is pretty much an expected thing. I don't know of anyone ever thinking twice about it. In fact, if you spend any time around commercial hydraulics (tow truck winches, cranes, front-end loaders) and listen, you'll hear the hydraulics whining whenever they're used.
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BlackWorksInc
New member
I've noticed mine does that at first start up in cold weather (like 20 or lower). Could just be a fluid deal. Mine is pretty clean considering I threw a new rack in a few months ago.
snowboardwcu
Member
just a push to make sure the level is actually full. mine appeared full for months (while i troubleshot steering issues) and when I finally went to do a flush, i found the "fluid level" was "dried crusty old fluid" level instead. reseviour was empty.
ATF only folks....
Started getting a whine on cold days(first noticed around 35) cold start only while turning wheels, was silent when the steering wheel stayed in the same position.
Got a power steering flush hoping for it to go away but it's hasn't gone away yet.
The sound goes away completely within maybe a minute or two once I start driving. Planning on replacing the pump, the guys I normally use are pretty booked and they're friends so I try to not rush them for jobs that can wait.
Anyone drive around with the noise for awhile? Did you just let the car idle longer before you drove or just deal with the whine? It's not super loud yet but I think its louder the colder it is.
Got a power steering flush hoping for it to go away but it's hasn't gone away yet.
The sound goes away completely within maybe a minute or two once I start driving. Planning on replacing the pump, the guys I normally use are pretty booked and they're friends so I try to not rush them for jobs that can wait.
Anyone drive around with the noise for awhile? Did you just let the car idle longer before you drove or just deal with the whine? It's not super loud yet but I think its louder the colder it is.
Inv4drZm
Senior Member
If it bugs you go ahead, my noise is back this year but it certainly isn't bothersome enough to start throwing money at it.
Flash Runner
New member
Well I had the whole system changed earlier this year in August (rack was leaking and caused the pump to go bad). Replaced with rebuilt OEM parts... went through 3 pumps, 2 racks, and 3 sets of hoses, etc.. to finally get the nosie to disappear entirely.
Noise has come back, and is the pump as it changes when I turn the wheel. I guess it's just cold? The whole system is warrantied through the shop so I was thinking about bringing it back to check on it given the noise give me some concern since I just changed everything.
For now, I'm keeping an eye on the fluid level, and just remote starting the car to warm it up before I take off driving. Very surprised it seems more like a V8 issue than with the V6's.
Noise has come back, and is the pump as it changes when I turn the wheel. I guess it's just cold? The whole system is warrantied through the shop so I was thinking about bringing it back to check on it given the noise give me some concern since I just changed everything.
For now, I'm keeping an eye on the fluid level, and just remote starting the car to warm it up before I take off driving. Very surprised it seems more like a V8 issue than with the V6's.
Terminator03
New member
Excellent advice! I’ve seen that happen to people before with older vehicles, when they look through the translucent plastic assuming the fluid level is ok because it appears to be up to the line!
snowboardwcu
Member
thanks! was def a low point in my engineering "career" figuring that one out hahahaha.
Exact same thing happened to me. I thought it was full l but was completely out.
