Help diagnose a car issue

[SecondCor521]

1993 Lexus GS300 with ~177K on the odometer.

In the last few days, I've noticed what I would describe as a groaning noise.

The noise occurs when making moderate directional changes to the right. These directional changes are approximately half of a regular 90 degree right turn.

The noises only occur when the turns are moderately fast, say between 10 and 25 mph.

Imagine going around a roundabout / traffic circle when you're really wanting to go straight. That kind of turn and speed.

The noise does not occur on similarly parameterized movements to the left, or at any speed going straight.

The noise is definitely loud enough to be heard over road noise and other background noise.

It is medium pitched. It is not a grinding, clunking, banking, clicking, or squealing noise.

It sounds to me like it is coming from underneath the car somewhere. More to the front of the car than the back.

The car is driving, and has been driving fine. No fluid leaks of note. No wrong smells.

I've been doing my own oil changes for the past several years; I just change the oil and filter and check fluid levels like the wiper fluid, brake fluid, and coolant.

I can check my records, but to the best of my knowledge the suspension is all original.

I have a vague notion that some suspension parts (ball joints?) need to be greased regularly, so since I haven't been doing that I'm suspecting that is what the problem is.

I'm inclined to take it to my non-dealer auto mechanic and ask him to fix it, but I wanted to post here to get opinions first as to what the problem might be and what is proper to do about it.

Thanks for any input.

 

[Car-Guy]

Sounds like it could be a front end/suspension problem but I'd check my power steering belts for wear and power steering fluid levels first. Even if that checks out okay, I'd still be suspicious of the power steering system until I find the problem somewhere else.

 

[GrayHare]

Since that era joints have been permanently greased on many cars, but I've wondered how long that grease can last without refreshing. You're over 25 years and a decent mileage. Even so my first suspicion would be the front end wheel bearings.

 

[Scrapr]

Struts? WAG....not even a SWAG

 

[homestead]

Sounds like it could be a front end/suspension problem but I'd check my power steering belts for wear and power steering fluid levels first. Even if that checks out okay, I'd still be suspicious of the power steering system until I find the problem somewhere else.

+1

 

[SecondCor521]

Thanks all for the inputs and suggestions, I appreciate them.

After reading and learning a bit more:

The noise volume seems to vary with engine rpm, not wheel rpms.

The suspension seems to be performing fine - the car is stable, not bouncy, and does as OK as it usually does going over speed bumps and through dips in the road.

The noise could maybe be described as a whirring or buzzing sound.

I'm going off to confirm no leaks, try to find the power steering pump and check hoses and levels and color of the PSF.

It could be wheel bearings, although I do take very good care of the tires and the Discount Tire people haven't said anything about tire wear. That having been said, it's been about 7K miles since my last rotation (it's due for one); plenty of time for a problem to have developed.

Could be ball joints I guess?

Key point is that when driving straight or over bumps, there is no sound at all (well, not this sound, anyway). So I think it's not the struts?

Also, again, the noise is only on right turns, never on left turns. Why would a PS pump only make bad noises when turning right and be OK when turning left?

 

[Scrapr]

If the noise varies with engine RPM it's not struts, PS pump, suspension or bearings.

another WAG....heat shield on cat converter. Possibly a vacuum pump/hose. Buzzing makes me think body panel or other protective shield. Smooths out as speed increases and/or road noise covers it up

it's 26 years old. By the sounds of this it's going to leave you stranded beside the road next week. I'd be car shopping....<sarcasm>

 

[SecondCor521]

Buzzing probably was too strong of a word.

Anyway, I have made lots of progress:

I decided to check the power steering fluid reservoir level first. The car was cold and the fluid was not even to the bottom of the dipstick, let alone to the bottom of the "cold" range.

I went to Walmart to buy some Dextron II ATF per the owner's manual. While I drove there, I paid more attention and the noise was starting to occur on left hand turns also. It was quieter, but still definitely there.

Came home, filled the reservoir too high, drained it back down to close to the proper level. Since I'd driven it back and forth to Walmart twice, I decided to go with a level between the top of the "cold" range and the bottom of the "hot" range.

Drove it around the block to test, and the noise is gone!

...

I took a more careful look at my garage floor, and there are some small red stained areas in the larger dried out oil stained area. So I think I may have a small leak in the steering system.

...

My "logic", which was totally wrong, was that the power steering system fluid reservoir level never needed to be checked because it wasn't in a translucent plastic reservoir like my brake fluid and my windshield wiper fluid. It's a solid metal can with a tight lid on it - how could anything leak out of there? Obviously brain dead, in retrospect.

...

My totally amateur theory is that right turns are more susceptible than left turns because the power steering pump in the car is on the driver's side of the engine, and so because the car rolls slightly to one side when in a turn, a low fluid level is triggered sooner in one turn direction than the other.

...

I checked my records, which show absolutely zero work to the power steering or suspension to date. So it is original dating back to the delivery of the vehicle to the first owner on 8/30/1994.

...

I have zero intention of shopping for a new vehicle any time soon. Thanks for the suggestion, though

...

Thanks again to all.

 

[atmsmshr]

Good show on sorting out the issue yourself! If you had gone to a mechanic they may have tried to talk you into a new steering rack, pump and hoses.

That being said, a lowering level and red spots on the floor indicate a leak, so you need to keep an eye on the symptoms.

As winter approaches, the power steering level will lower slightly with the falling ambient temperature; so if cold level is marginal the symptoms return.

You may consider looking for a leak in the accessible hose joint areas. If identified, then ponder the need for permanent repair.

Have to admit, on any of my cars with minor leaking PS fluid I simply monitored and topped off when needed. On DW's 2004 Lexus RX330 with a leak, I had the power steering rack replaced right away.

 

[DrRoy]

I thought it was the power steering too.

 

[ponyboy]

CV Joint.

 

[ncbill]

Buzzing probably was too strong of a word.

Anyway, I have made lots of progress:

I decided to check the power steering fluid reservoir level first. The car was cold and the fluid was not even to the bottom of the dipstick, let alone to the bottom of the "cold" range.

I went to Walmart to buy some Dextron II ATF per the owner's manual. While I drove there, I paid more attention and the noise was starting to occur on left hand turns also. It was quieter, but still definitely there.

Came home, filled the reservoir too high, drained it back down to close to the proper level. Since I'd driven it back and forth to Walmart twice, I decided to go with a level between the top of the "cold" range and the bottom of the "hot" range.

Drove it around the block to test, and the noise is gone!

...

I took a more careful look at my garage floor, and there are some small red stained areas in the larger dried out oil stained area. So I think I may have a small leak in the steering system.

...

My "logic", which was totally wrong, was that the power steering system fluid reservoir level never needed to be checked because it wasn't in a translucent plastic reservoir like my brake fluid and my windshield wiper fluid. It's a solid metal can with a tight lid on it - how could anything leak out of there? Obviously brain dead, in retrospect.

...

My totally amateur theory is that right turns are more susceptible than left turns because the power steering pump in the car is on the driver's side of the engine, and so because the car rolls slightly to one side when in a turn, a low fluid level is triggered sooner in one turn direction than the other.

...

I checked my records, which show absolutely zero work to the power steering or suspension to date. So it is original dating back to the delivery of the vehicle to the first owner on 8/30/1994.

...

I have zero intention of shopping for a new vehicle any time soon. Thanks for the suggestion, though

...

Thanks again to all.

Lucas Power Steering Stop-Leak worked for us to permanently fix a leaking rack on our minivan over a decade ago.

 

[rick55]

My vote’s the ps pump.

 

[rpguy4]

Lucas Power Steering Stop-Leak worked for us to permanently fix a leaking rack on our minivan over a decade ago.

+1 - Stop-leak fixed a small leak in our 2009 Sienna

 

[SecondCor521]

Lucas Power Steering Stop-Leak worked for us to permanently fix a leaking rack on our minivan over a decade ago.

Yeah, I saw that stuff at the store and wondered about it.

Given the encouragement here, I'll probably try it in a while. If I added any now it would overfill the reservoir.

(I'm assuming the instructions will say how much to add and it's more than a tablespoon.)

 

[Car-Guy]

I don't like to use stop leak stuff but I've use Lucas PS stop leak and it's worked on slow leaks. Personally, I usually like to find and fix the actual problem, when I have the time and before it becomes worse, but that's just me. I've also seen "some" of the stop leak stuff cause other problems in the long run.

 

[rpguy4]

I added the stop-leak fluid when the power steering fluid was low, and brought it up to the cold-max line. It didn't take much, and it seemed to do to the trick.


Edit: In my case, it was AutoZone's stop-leak fluid. YMMV.

 

[SecondCor521]

Yeah, the other thing is that I've been looking at the Lucas stuff, and all of the problems it claims to solve, I simply don't have. The steering wheel play is correct, and the car steers perfectly normally. Other than the one noise, there is no clunking, grinding, etc.

There is a quieter version of the sound I described in the OP when accelerating from about 5 to 30 mph. I really don't know much about this stuff, but now that I've read some I could imagine it being from the vanes inside the pump, or the increasing workload from the engine revving...or something.

The leaks on the garage floor are only a handful of little dry spots about the size of a nickel or a quarter. I don't have a lake out there. The fluid level is the same as it was a couple of days ago, so it's a slow leak. There does seem to be fluid and dirt on the outside of the various lines and gaskets underneath the reservoir, and again, this is all original stuff from when the car was built 25-26 years ago, so there is probably a cracked gasket or loose fitting or something like that going on.

 

[38Chevy454]

You can remove the low pressure hose (return) from the reservoir and run into another container. Then with engine idling turn the wheels right and left, while filling back with the stop leak fluid. Stop when new fresh color fluid comes out. This will flush the old 180k fluid out and allow the new fluid with stop leak to fill the system.
The stop leak fluid sounds like it may work for your vehicle since it is a small slow leak. Flushing out the old fluid certainly won't hurt any.

 

[wolf]

You can use the turkey baster method. Remove old power steering fluid from reservoir.
Then refill. Do these "many" time until the fluid is much clearer.

If the reservoir opening is to small. Harbor freight, has cheap, I think, $4.95. plastic pumps that work great.

On, my 2002, Toyota Camry, I used the Harbor freight method. One good news, was
the Toyota used, Toyota Transmission fluid, for the power steering fluid.

So, pretty cheap process. Yep, your description, pointed to power steering pump.
Renewing the fluid may prolong the life of your pump.

 

[ncbill]

Yeah, the other thing is that I've been looking at the Lucas stuff, and all of the problems it claims to solve, I simply don't have. The steering wheel play is correct, and the car steers perfectly normally. Other than the one noise, there is no clunking, grinding, etc.

There is a quieter version of the sound I described in the OP when accelerating from about 5 to 30 mph. I really don't know much about this stuff, but now that I've read some I could imagine it being from the vanes inside the pump, or the increasing workload from the engine revving...or something.

The leaks on the garage floor are only a handful of little dry spots about the size of a nickel or a quarter. I don't have a lake out there. The fluid level is the same as it was a couple of days ago, so it's a slow leak. There does seem to be fluid and dirt on the outside of the various lines and gaskets underneath the reservoir, and again, this is all original stuff from when the car was built 25-26 years ago, so there is probably a cracked gasket or loose fitting or something like that going on.

On some vehicles the power steering fluid reservoir has a crude screen molded inside the plastic tank...it eventually clogs & can't be cleaned.

The solution is to replace the reservoir tank with a new one...cost about $40 on my old Chrysler minivan (yes, you can re-use the fluid)