Modern cars require about as much maintance as a toaster except for the fluids and filters about the only thing that needs attention are the spark plugs. Many manufactures recommend replacement as high as 100K. The advent of many new electrode metals, platinum the most popular, have allowed this as the recent engineering of fluids extended there life. I think that many hours of testing go into the spark plug selection so I only recommend replacing with the recommended. There are several gimmicks on the market and none of them work so stay away from them. The only one I have used is the Champion truck plug and I didn’t notice any improvement but they looked great with the gold body.There are 2 common types of plugs the tapered and gasket. Except for access on some vehicles replacement is simple. I do recommend using a torque wrench mandatory when installing the ones with a gasket and will prevent future problems with the tapered. The crush of the gasket is crucial to provide a proper seal and never reuse the gasket. The tapered will be easier to remove if not over tightened and none are easy to remove at 100K. One last tip when replacing plugs consider replacing the wires and put a dab of dielectric grease on the connector it will prevent corrosion and make the wire easier to remove.
Many techs do not use the compression test as a diagnostic tool as there are numerous features on most scopes to replace it. Burn time is perhaps the most used diagnostic tool as it will also show problems with the spark and injectors as well as a weak cylinder. In many instances the check engine light will be on and a code will tell us the problem cylinder. The cylinder balance test is also a replacement for a compression test and is usually followed by a leak down test on the offending cylinder. A Leak down test pumps air into the cylinder and measures the per cent of leakage and by where the pressure is escaping you can tell if it is an exhaust, intake valve or piston problems. When spending some time in some various shops I was also surprised at how many techs use the good old vacuum gauge or the electronic equivalent of one, the electronic one can be graphed and gives the tech a lot of diagnostic info. Also many still use the wet and dry test to check rings and engine condition. The wet dry test is when you check the compression on a dry cylinder and then give the cylinder a couple squirts of oil and check the compression again if it is higher you have a ring sealing problem. The problem here is that many engine compartments prevent access to give the cylinder a squirt of oil. I have seen some vey inventive hose arrangements to try get oil into the cylinder and they usually end up making a mess. Most DIY do not have the diagnostic equipment so they have to rely on the good old compression test. Compression should be within 20% of other cylinders; unless they are all even and one is low then I would like to see less than a 10% difference. This will set a check engine light. Compression gauges are not known for their accuracy that is why the difference is more important than the actual reading. If the gauge fails to hold pressure replace the schrader valve at the end of the hose. It looks like a tire valve but it is not but one can be used in a pinch.
Bleeding brakes or a clutch system The correct method is to use a vacuum pump and the bleeding kit that comes with it. The kit is a small bottle to hold vacuum and several hoses.For lack of a pump. Open the bleeder screw, have a helper push the pedal to the floor slowly, tighten the screw let the pedal return repeat as necessary. Be sure to keep the fluid full.Or install a hose on the bleeder screw and insert it into a container filled 1/2 way with brake fluid. Open the bleeder screw and have someone pump the clutch pedal slowly until no bubbles are present.Clutches can be a problem to bleed one method I have used with success is to remove the master cylinder cover and let it sit overnight. Doesn’t hurt to give the pedal one very slow pump when you remove the cover, use caution as fluid will squirt out on the return stroke. On a rare occasion I have had to remove the master cylinder and bench bleed it, install adapters with hose in pressure line route to fluid container and pump. Be sure the bleeder screw is higher than the rest of the cylinder. With ABS a scanner may be necessary if air has entered the ABS system module.
Where does my brake fluid go? When checking the fluids, on a weekly basis as you should be doing, you notice the brake fluid slowing dropping, with no noticeable leaks, until you decide it is time to add some. Hint: deplete the pressure in the system if you have ABS or for that matter on any vehicle built since 1990, safer to pump the pedal a few times then end up with a face full of fluid.As your brake pads wear the cylinder in the caliper moves out to take up the space from the wearing pad. Many new vehicles have large calipers and pistons and this is where your fluid is going. This is also why it is important to remove the master cylinder cover during brake replacement. Never let the fluid from the caliper return to the system when compressing the caliper this will contaminate the fluid and will cause ABS problems. Loosen the bleeder screw when compressing the cylinder and clamp off the brake hose. A set of plastic pliers is now available to block off the hose and they will not cause any hose damage. They are also self locking and cheap. Have heard of several internal brake hose failures, which are a SOB to diagnosis, I expect most of these are from improper pliers being used to block off the brake hose. Do not use a vicegrip better to go without then use them as a clamp. When I replace brakes I also exchange the fluid it is an easy time to do it and will prevent problems in the future. I have solved many ABS problems by changing the fluid. Do not let the fluid run low as you will need a scanner to reset the brake lite on many vehicles. Without the use of a scanner some of the fluid will not be replaced, on some ABS units, but unless it is in really bad shape this should not be a problem. If it is in bad shape seal the system, start and pump the brakes several times, and then run some more fluid through the system. Still bad time for a trip to a shop. Remember fluid does not run through the system it merely applies and releases pressure. This is why it is important to remove the fluid from the caliper as it is contaminated with wear from the piston seal and the outer wall of the piston the seal does not keep everything out.Remember it is a problem if your car doesn’t start but it is a huge problem when it fails to stop.
This is the time of year when we start to see overheating problems, unless you live where I do as we have had an unusually cool summer, There are several things that can cause overheating, thermostat, low coolant, inoperative cooling fan all of these are easy to check if you don’t have a noncontact thermometer I would suggest purchasing one Sears has one for a little over $40 on sale. You will be surprised at the uses you will find for it. One overlooked problem that can cause overheating is a blocked space between the radiator and condenser. Easy to clean at the local car wash or at home with a garden hose. Also check for blocked passages in the radiator a simple check with a flashlight if they are blocked the radiator will have to be removed and professionally repaired. I recommend flushing every other year. To flush simply locate the input heater hose and attach a hose let the water run, until it comes out of the top of the radiator clear. If the coolant is severely dirty you may want to add a chemical flushing additive.There are also some odd problems that can cause overheating, a lose water pump impeller, an obstruction in the system IE a collapsed hose, air in the system. Do not run the old coolant into the storm drain as it will pollute some places this is also illegal.
Cleaning your battery is just a matter of common sense. The myths that coke works as a cleaning agent is true but why waste part of a rum and coke. Baking soda also works but on older batteries with vents on the top or if you have a loose post some may get into the battery and then you won’t have to clean the new one. Most cleaning agents are baking soda so also be careful with these. The solution I use is 5 parts water one part vinegar one part oxy clean and a squirt of Dawn. I usually preclean with any orange or green heavy duty cleaner they all are about the same be sure to rinse thoroughly before using the second solution. A few minutes with a brush, and you have a clean battery it doesn’t hurt to remove the battery once in awhile and clean the tray, always check the area between the battery and the inner fender many manufactures run wires here Chrysler vans are prone to problems at this location. The connection between the terminal and the post should be shiny there are several brushes made for this, there is also a metal scraping tool but this removes to much material that may cause problems at a later date. One last hint that I have mentioned before spray the terminals with clear lacquer not only will it keep then clean but they will also look good and be easy to clean next time. If you need experience check for parasitic voltage and do a voltage drop test on the terminals you may be surprised.
Parasitic voltage is not a rare disease but it can cause problems when present. The most common parasitic voltage problem is when a battery top surface becomes contaminated with certain materials and creates a connection between the positive and negative terminals, most common on top past batteries, the amount of voltage is small but can cause problems over time. Very easy to check with a volt meter, check between both post and the top as in very rare instances it will only be present on one terminal.The other place parasitic voltage can cause a problem is the cooling system. The main cause is the different metals in the engine create a voltage in the fluid. Here again easy to check positive test lead in the fluid the other to the negative battery terminal. There should be no voltage present.FYI A voltmeter should be RMS capable as most are today and be able to read milli volts. I use a craftsman that sold for around $20 on sale.
If your check engine light comes it is not the end of the world or at least it may not be as expensive as you may think. The first item to check is your gas cap is it tight or have you filled recently while the engine was running, if so wait about 6 key cycles, engine from cold to hot and a several RPM changes enough to cause a vacuum change, this should turn it off. If not then visit one of your local parts stores most will check for codes at no cost. Beware however it is there job to sell parts so if the code indicates a bad EGR valve they will try to sell you one. However check for other problems first, are all the hoses and electrical connectors secure. It is a good idea to unplug all electrical connectors to the effected sensor, this will sometimes help, rarely but it doesn’t hurt. Check to see if the item needs cleaning mainly in the case of an EGR or IAC also some vehicles have a filter, Honda does on many of their IAC and Ford on the Fuel EVAP system. Still a problem then it is time to check the manual, some you can find online or visit your local library, these can also be checked online in some cases. There is usually a tree to troubleshoot the affected item. Still at a loss replace the sensor they are usually cheaper than having a shop check it out. The only exception to this is the O2 sensor if you have no exhaust leaks if it throws a code they are usually defective. They also require special equipment to diagnosis.Do not put a match book cover or a piece of tape over the light as this will lead to more expensive repairs down the road. I have seen the light bulb removed in several cases. Just remember don’t panic your engine is not going to explode although I have heard of parts stores hinting that this may happen.
It is that time of year when you try your AC for the first time and no cold air. Don’t panic; listen for a clicking which will be the AC compressor clutch. If it is clicking on and off you are probably a little low on Freon. If it not engaging you are probably still low on Freon. More than likely you will have a 134A in your system, if your service valves have threads and are small take it to a shop and have it retrofitted. Purchase a kit from the parts store, keep the gauge and hose and next time you will only need Freon.Be sure to clean the service valve before attaching the hose even a grain of sand can damage a compressor. The hose slips unto the valve and locks in place with a click. Attach the hose to the low pressure side this will be the larger of the two hoses. Holding the can hose end down tighten the valve to pierce the can and then back it off to start filling, shaking the can will speed up the process and assure getting all the contents out. Continue filing until the pressure is in the green, if the compressor was not running you may see the gauge jump and hear the compressor kick on and off, this is normal. When the gauge is in the green shut off the can and remove the hose. You should now have cold air if not it is shop time unless you have some AC experience and a set of gauges. When servicing the AC it is a good idea to also check the belt for condition and the condenser for any blockage between the radiator and the condenser, easy to clean at the local car wash with a pressure wand. Also check the area to the front of the windshield this grate area should be free of debris.Have seen numerous vehicles with crud on the evaporator blocking air passage this usually have a musty odor, some vehicles can be cleaned by simply removing the heater blower motor other take drastic disassembly. If you have an odor and good air flow there are several products on the market that do a fair job of removing the odor. I am usually not cautious enough when performing repairs but I always wear gloves and a face shield when working on AC, Freon is really cold and it hurts when coming in contact with skin this I can tell you from experience.
I have heard of instances where the cost to replace a charcoal canister being upwards of $700. This is a DIY job if there ever was one; first locate the canister it is either by the fuel filler neck or in one of the front fender wheel wells. Most local libraries have an online source you can find the location if you have a problem. You may have to remove a wheel for access to the rear or possibly the battery if it is in the front, worth it to save several hundred dollars. Dispose of the old one properly more of a problem if it is saturated with fuel. If it is saturated with fuel find the reason before replacing or the new one will do the same. Several causes for fuel saturation, overfilling your tank is the usual cause. No you cannot dry them out but I have thought about using one to start a bon fire however. Guys used one to start a barbecue at the shop once and it melted the barrel they used, wasn’t much of a barbecue to start with.