This month, we answer questions related to chemicals, cleaners, lubricants and additives. These products—and the right knowledge for using them—can be a real plus in fighting everyday battles in the shop. Since knowledge is power, follow along to stay in front of the challenges that lie ahead.
Q. We repeatedly get complaints from customers about a musty smell from the A/C vents in their cars. There doesn't seem to be any rhyme or reason to it and the A/C cools just fine. What's up?
A. Vehicles exhibiting this condition have mold growing way down in the deep, dark abyss of the A/C ducts. The problem begins when debris of an organic origin (leaves, bugs, etc.) accumulates and becomes food for mold spores. Moisture and engine heat nurture the mold until it's finally noticed by the sense of smell. Although the problem can occur at any time, it's usually noticed when the A/C is first turned on in the spring. For those with allergies, this problem can be a nightmare. About 15% to 35% of vehicles equipped with air conditioning will become infected, depending on climate, even more so in hot, humid climates. Also, vehicles driven for short periods with the A/C on are more susceptible to getting the problem than those driven for longer periods. While some techs flirt with the use of household disinfectants to kill the mold, the real answer is a special chemical solution from your supplier made for this purpose. You apply it with a special gun to reach into the deep recesses of the air conditioning ducts. Spraying the evaporator core is especially crucial. Allow the solution to soak for a short while and then flush it away with ordinary tap water. This process kills the mold at its source. There are even ultrasonic tools now available for this type of cleaning. Although the frequency of application is based on an as-needed basis, some shops offer the service as part of an annual, air conditioning service package. Although you can't entirely prevent the problem from recurring, you can take a couple of preventive measures to help your customers. First, ensure that the evaporator drain is flowing freely to drain off water and ensure the cabin filter gets changed regularly. Some companies also offer mold inhibitors to deter growth.
Q. When specifying fluids for vehicles, we use owner's manual information or service information stating the recommendation of the manufacturer. Is there any other source we should be aware of?
A. As vehicle and fluid technologies change, fluid requirements and specifications may also change. A new fluid specification may supersede an old one, replacing what was originally required. For the latest recommendations on fluids, make sure to check technical service bulletins as they often contain updated fluid specification information. Don't take this lightly; this may be required to protect an owner's vehicle warranty.
Q. Manufacturers are all over the place with their coolant specifications. Some aftermarket coolants claim universal coverage for all vehicles and that would sure make things easier. Is a universal coolant too good to be true?
A. Without question, it's a literal "alphabet soup" of coolants available today for all the different manufacturers. Rather than making this a debate about selection, perhaps the best answer to coolant selection lies in what's at stake for the owner's vehicle. Manufacturers spend a good deal of money proving out their coolants with their engines and specify a certain type for warranty coverage. To best protect that coverage, follow the manufacturer's recommendation to the letter to ensure warranty protection. Again, this isn't to say that universal coolants are a bad choice; they're just not the factory fill from the car maker. Like any fluid, make sure to check service bulletins to make sure there isn't a revised coolant spec from the original.
Q. When selecting a cleaner for a given application, is there a general rule of thumb to help ensure the right choice?
A. You will need to use several different cleaning products for the various services you perform. These cleaners contain different chemical mixtures and some can damage vehicle components or paint. Match up a cleaner by comparing its stated purpose to the task at hand. Never use a chemical any stronger than what’s needed to do the job. You should also be aware of the Material Safety Data Sheet (MSDS) information for any cleaning products you use.
Q. We’ve heard about broken spark plug nightmares when removing spark plugs in Fords with 3-valve, V8 engines. Are there any tricks we can use avoid problems when tackling one of these jobs?
A. Ford V8 engines from 2004 through 2008 with 3-valve cylinder heads cause technicians grief everyday during spark plug removal. These vehicles use a unique spark plug design that tends to seize and strip threads in the cylinder head if you're not careful. To reduce problems during removal, Ford states that you should only remove the plugs with the engine at room temperature. First. blow out the spark plug well area with compressed air. Then, back out the spark plugs about 1/8th of a turn, but no more than ¼ turn. You then apply ½ to ¾ of a teaspoon of approved carbon cleaner to each of the spark plug wells. Let the cleaner soak for for at least 15 minutes. Do not use more than than the recommended amount of cleaner. After the waiting period, alternately tighten and loosen each spark plug, continuing until turning effort becomes noticeably less. Remove the spark plug the rest of the way.
Q. Over the years, engine oil service grades have come and gone. What current grades and rating certifications do I look for to ensure I'm using the right oil for a given application?
A. First of all, engine oil viscosity ratings are set by the Society of Automotive Engineers (SAE). These ratings come in the form of 10w30, 5w40 and so on. Service grade certifications, on the other hand, are set by the American Petroleum Institute (API) and these grades denote an oil's suitability for a given application. API periodically changes its service grade classifications and did so again recently by establishing the SN service classification. Introduced in October 2010 for 2011 and older vehicles, designed to provide improved high temperature deposit protection for pistons, more stringent sludge control, and seal compatibility. API SN with Resource Conserving matches the ILSAC GF-5 standard by combining API SN performance with improved fuel economy, turbocharger protection, emission control system compatibility, and protection of engines operating on ethanol-containing fuels up to E85.
Q. We service some Volkswagens that have a VW oil spec of 505.01. We've found a few oils that say they meet this specification but we want to be sure. How do we know?
A. Volkswagen has its share of in-house specifications and it's critical to pay attention to details. You will find there are numerous oils that claim to meet the 505.01 specification, but that doesn't mean a given oil has been approved by VW as meeting that standard. To be sure, ask the oil manufacturer for documentation that their oil has been approved for 505.01 applications by VW. The same holds true for other VW oil specs.
Q. Purchasing chemicals seems to be a lot like buying “snake oil”. There are so many products that claim to do all sorts of miraculous things. How do I begin to find the real products among all the smoke-and-mirror stuff?
A. The only real way is to try different products, to separate the truth from the fluff. Try one company's penetrating oil and if it works well, imbed the use of that product into your everyday workflow. With the right choice, it can save a lot of labor and frustration when working with stubborn fasteners during undercar work. If you have good results, perhaps try cleaning and solvent products from the same company to see if you have good results there as well. When it comes to solvents, always err on the side of caution. While an aggressive solvent may work well at attacking carbon deposits or other unwanted debris, solvents can also attack certain materials and damage them.
Q. How often should we lubricate air tools?
A. It's best to lubricate your air tools with every use, adding about a teaspoon of air tool oil to the tool's inlet. An automatic lubricator is an even better bet. Make sure your shop air supply is dry to reduce the likelihood of moisture wreaking havoc with your air tools.
Thanks for checking out this issue's Tool Q&A. Remember to forward your questions to PTEN so we can consider them for an upcoming issue. See you next time.