hey mechanics - anyone want to diagnose what's wrong with my truck?

I drive a 96 Chevy Silverado pickup.

We had terrible rain here in Houston a couple of days ago (5-7 inches in about 3 hours) and I had to drive through a few spots of high water to get home from work. My car never stalled and I don’t think that the axle was ever completely submerged. I made it home OK and my car seemed to be fine, so I said a prayer and went to bed.

Yesterday I was driving in to work on the freeway and just as I start to get downtown (I had been driving about 15 minutes), I noticed a loud whine coming from the engine that seemed to be in concert with the RPM’s. For some reason this whine got louder whenever I turned the wheel and there was a distinct diminishing of accelerating power at lower speeds/RPMs.

I parked the car and came inside and a coworker told me that it sounded like I may have gotten water in my power steering case and that I needed to go to the mechanic and have it checked out. The car had been sitting about 30 minutes at this time and the problems did not repeat on my way to the shop.

The mechanic looked it over during the day yesterday and said there was nothing wrong. He specifically said there was nothing wrong with the power steering. I took my car and drove home and after about 15 minutes of driving, the problem came back.

It happened again this morning so I went straight back to the mechanic who was able to witness the noise himself.

So now my car is stuck at the shop and I have no idea what the problem may be. I am now afraid that I got some water into the transmission etc etc. A friend suggested that maybe I needed to repack the wheel bearings as water might have floated out the grease.
Does anyone have an theories? I know very little about cars and I would really like to have some idea what may be the problem as I wait on the inevitable phone call of doom.

Could be a lot of things.

It could be as simple as the water spalshing a pebble or twig up to where it’s rubbing a belt.
Running through water often causes electrical problems. The loss of power make signal a problem with your computer, ignition module, or voltage regulator. You look at these things funny, and they’ll break, and they hate water.

The whining sound could be just about anything from a loose belt on your hydraulic pump, to you needing a whole new steering box.

Good luck.

Chevy’s though are usually pretty tough so think happy thoughts.

I’ll hazard a WAG… as Scylla indicates, it could be a number of different things, but I’m guessing it’s the alternator. My dad had '90 or '91 Silverado (I forget the year) that had two alternators go out. He subsequently sold it to my brother who went through another one. I remember that the first time it happened, a rock got thrown up inside the thing, and it ripped itself apart. The last one actually caught fire.

That reminds me, I need to buy a fire extinguisher for my car…

I assume that you have personally checked the power steering fluid. If the fluid level is ok, then I doubt that it’s the power steering.

Could you add more information about the truck? Is it a two wheel drive or 4WD? Is the whine high or low in pitch? (Splitting a necessary hair,) does the whine rise and fall with engine speed or with the speed of the truck? Does it whine in park, neutral, drive or reverse, or all of the above?

Did a “friend” put a tie-wrap on a fan blade? :slight_smile:

I may not be able to post again today, but adding more information should help the other folks, and I’ll reply tomorrow if I think of anything.

(Absolutely irrelevant tangent)
Good God! 12:35, right in the middle of lunchtime in CST, and the preview went through in three seconds! Lynn, what the #&!! happened???

Alternator would be a good guess, along with most other accessories driven by the engine.

As for the wheel brgs, its not a bad idea. Its not that the grease gets “floated out” with the water, more than water gets in and stays. It is also possible water made its way into the diferential via the breather plugs/axle seals, so it would be wise to do the gear oil as well. If you have a 4X4 do both.

Gee guys, thanks for the help!

It’s a 2WD with the 305 V8 engine.

The noise sounds almost like a low-pitched vacuum cleaner - maybe it’s more of a buzz that a whine - that goes up and down in tandem with the engine RPMs. As best as I can tell it’s only there when the car is moving (or it may just be so low in pitch that I can’t hear it when the engine is idling slowly)

The noise is worse when I turn the wheel, which, given some of my own research today, makes me think it’s something with the power steering, and as I now know that the PS pump is attached to the crankshaft, I am suspecting it’s the pump.

My fear is that it’s the transmission. However, the car is running fine and I haven’t felt anything abnormal from the transmission (aside from the perceived loss of power at slow speeds). Would a problem with the transmission make a similar noise?

I had the alternator replaced last October. Back then, before it started whining, the voltage indicator was waving all over the place. This time the voltage indicator hasn’t moved at all, so I am skeptical that it’s the alternator.

thanks guys

And no, I did not check the PS fluid myself, I just took it into the shop and asked them to check it for me during a routine oil change.

With engine running and transmission in park/neutral does it whine?

Does it whine (or get louder) when you turn the wheels while in park/neutral?

If yes to the second, the power steering pump is a very likely the culprit and probably just coincidental to running through the water. If the water was high enough to get into the PS pump, then you definitely need to consider changing your differential lube and inspecting/re-greasing wheel bearings.

If the water was below axle height, but you went through it at speed (anything much over an idle), you may have splashed enough up into the pump to damage it, or caused the belt to slip enough that it is too worn to maintain proper tension. So you may want to check the belt out too.

Hey, and quit calling your truck a car! :wink:

Top up the power steering fluid. I’ll eat my hat if the level is ok*. Besides being low on fluid, there’s not much that can make a power steering system whine.

There is an outside chance that the belts are slipping. You can check this by misting a little water onto the belts while the engine is running (and whining.) If the noise goes away, replace the belts, or you can just get a can of “belt dressing”, which may or may not permanently get rid of belt noise.

bernse, I would worry about the bearings too, but bad bearings rumble, and take a while to wear out.
*[sub]It’s an easy bet to make: I look stupid in hats, so I don’t own any.[/sub]

While you are looking at the belt, also look at the pulleys. Its possible that you splashed some crud into the bearings on the pully, and it doesn’t turn as freely as it should.

Gotta add the disclaimer that I have never worked on a truck. I have however worked on many cars. When I hear a whine sound that changes volume and/or pitch with turning wheels, I instantly think of CV joints. So, I must ask:

  1. Is it front wheel drive?

  2. When you say was it a low-ish pitch?

  3. Have you ever had the CV joints replaced (or front axles)?

  4. Does the volume change with RPM or does it change with speed? (to test, put truck in park/neutral and change RPM, listen) If it makes the noise in park/neutral with change in RPM, it isn’t CV joints.

  5. Does it happen at slow speeds? Roll down your window, turn the wheels all the way to the left, stick head out window, start truck moving slowly and go up to about 5 mph. Do the same with the other side. (turn the wheel all the way to the right - don’t stick you head out the passenger side window :slight_smile: )

Again, I’ve never worked on trucks, but if you have loose seal around the CV boot, water can enter the boot and start some damage.

If it’s a CV joint problem and it’s caught early, you might be able to repack the system and replace the boots and get out for $100 or so. If damage has been done, you may be in for $400 to replace both axles.