Squeal or whine is no good with power steering

Q I just had my power-steering pump replaced for the second time on my 2003 Caravan. It still squeals like fury when I first drive it in the morning when the engine is cold, just as the last pump did and then continued to do off and on even after the van had warmed up. Why didn't the new pump take care of this problem?

A I would be more inclined to associate the squeal with the serpentine belt rather than the pump. Granted, excess mechanical drag from the pump can cause the belt to slip and squeal, but before focusing on the pump I'd check the condition, tension and alignment of the belt. I might even try cleaning all the pulleys with an aerosol brake cleaner and install a new belt, particularly if the current one has more than 50,000 miles on it. It might be that the squeal is coming from or caused by a different belt-driven accessory.

A more typical noise from a power-steering pump is a high-pitched whine, not a squeal. Usually, if the steering wheel is stationary, meaning that the steering rack is not "asking" for assistance from the high-pressure fluid from the pump, there's little or no noise. As the steering wheel is turned and the steering gear asks the pump for assistance, the pump might whine or howl a bit.

Here's a simple test. Buy an aerosol can of brake cleaner, install the little plastic extension nozzle, open the hood with the engine off and find a safe way to spray the aerosol on the ribbed side of the belt. Make sure clothing, fingers, etc., won't get caught in the belt. Start the engine, and while you're hearing the squeal, spray the aerosol on the belt. You can try this on both sides of the belt. If the squeal stops instantly, then restarts several seconds later, the noise is being generated by belt slippage. If there's no change in noise, the problem more likely is associated with one of the belt-driven accessories.

Whenever the power-steering system is opened on this engine -- to replace the pump, hose or fluid -- it might require "bleeding" with the engine shut off.

Chrysler calls for its MS9602 fluid, which is red, and suggests bleeding the power steering with a special fitting on the power-steering pump to allow a vacuum pump to "pull" 20 to 25 inches of vacuum on the system for three minutes. Top up the fluid and repeat until the fluid level no longer drops.

And finally, if the noise is coming from the power-steering pump, the system has been properly bled but it's still making noise, trying adding 2 ounces of SeaFoam Trans-Tune to the reservoir.

Q I have a 2002 Chrysler Town & Country with a 3.8-liter engine. After the car sits for a day or so, the power steering will not work until the engine is revved up for a short time. It works fine until the car again sits for a day or two. What is the likely cause of the problem?

A See above, particularly in regard to the correct fluid and bleeding the system. When you start the engine cold, does the belt squeal? If so, slippage might not be allowing the pump to spin fast enough to build pressure. A worn seal or a problem with the steering rack could also cause this symptom. Check the power-steering fluid level -- bleed as described above if necessary -- and try the Trans-Tune additive.

Q I have an '06 Dodge Caravan. The owner's manual calls for 5W-20 oil when changing. The shop says 5W-30 is OK to use and didn't have 5W-20 in stock and would have to go out to get it, and would charge a couple of bucks a quart more for the oil change. How important is it to use 5W-20, and why recommend 5W-20?

A Chrysler calls for 5W-20 engine oil for the 3.3 liter V-6, or 5W-30 oil for the 2.4 liter four-cylinder engine, so it depends on which engine powers your Caravan. Assuming it's the 3.3, stick with the 5W-20 as recommended, and as listed on the oil filler cap. Chrysler doesn't suggest 5W-30 as an alternative, although I suspect it would function satisfactorily. But like Ford and other carmakers, Chrysler is moving toward lighter-weight oils for slight improvements in fuel economy. The lighter the oil viscosity at operating temperature -- the "20" or "30" characteristic -- the less mechanical drag on moving parts.

Q I have a '99 Suburban with the 5.7L V8 engine. Can I use E85 in this? My local repair shop recommended against it.

A I agree. If the engine/vehicle was not set up as a "flex-fuel" vehicle capable of operating on both pure gasoline and E85, I would stick with gasoline. The engine was not built for and the engine management system wasn't programmed for high-alcohol-content fuels.