Tag: Auto Repair

Here Are the Most Common Car Damages Caused by Collisions

Anyone who’s suffered a car crash will tell you that even the tiniest of hits can cause major damage. Cars are built to protect passengers in case of an accident, which sometimes means they take more exterior damage to prevent harm to those who are inside. However, there are areas of a car more prone to damage than others.

Bumper Damage

Although both front and back bumpers can be damaged in a collision, front bumpers seem to take the most hits. As a result, according to Impact Auto Body, a third of all vehicular damage is to the front bumper. You can damage your bumper by hitting another car, a tree, an animal or even just a high hill or snowbank. If your bumper is damaged, it will either be repaired or replaced. Repairs will be made depending on the type and severity of the damage. Scratches can be buffed out or painted over, while dents have to put pulled or hammered out.

Dented Doors

Door denting is another common type of vehicle damage. If someone hits you in the side, it’s a safe bet your door will suffer some damage. According to the Law Offices of Gary S. Greenberg, while the extent of the damage typically varies based on speed, the sheer size of commercial trucks makes them capable of doing the most damage to a car and the people inside. However, small cars can do some real damage, as well. The extent of the damage to your door will be the main factor in deciding on repairs. If you are hit by commercial trucks and your car isn’t totaled, the doors often have to be replaced entirely. If hit by a smaller vehicle, the dents can sometimes be pulled or hammered out, and the doors are sanded down and repainted.

Broken Headlights

Just about any type of collision to the front half of the car will result in a broken headlight. The good news is headlights are relatively inexpensive, which means they’re almost always replaced rather than repaired. Oftentimes, the place where you purchase your headlight will install them for you for free, or as Car and Driver says, you can do it yourself.

Damaged Windshield

Like dented doors, the severity of the damage to your windshield will determine whether it’ll be replaced or repaired. Shattered windshields or windshields that have a crack all the way across will likely need to be replaced entirely. Smaller dings, spider web cracks, and other minuscule damages can be fixed by glass repair professionals. Many companies even offer the option of coming to your place of business and fixing your windshield while you work!

Wheel Damage

Because there is a tire on every corner of your vehicle, no matter where you’re hit, a tire is usually hit, as well, and they often sustain damage. A bad collision can knock wheels off their axes, rupture tires, or dent or can cause irreparable damage to your wheel wells. Wheels also take damage from everyday wear and tear. When damaged, if they can’t be patched or realigned, they’re replaced.

If your car has suffered any of the damages mentioned above, you aren’t alone. Car accidents happen every day and almost all result in some type of damage. Just do your research and see what kind of repair and replacement options are available to you.

If your car needs fixes on the inside rather than the outside as the result of a crash or any other circumstance, contact me and I’ll bring the car repair services to you!

How your cars A/C system works and Why you should clean the Condenser

Typical A/C system[/caption] The High-pressure Side All automotive air conditioning systems are (nearly) closed loops with a high-pressure side and low-pressure side. We’ll start with the high-pressure side as it leads from the engine to the passenger compartment. Compressor: The compressor is a pump driven by a belt attached to the engine’s crankshaft. When the refrigerant is drawn into the compressor, it is in a low-pressure gaseous form. Once the gas is inside the pump, the compressor lives up to its name. The belt drives the pump, which puts the gas under pressure and forces it out to the condenser. Compressors cannot compress liquids, only gasses. You’ll see as we go through the system that there are other parts whose job it is to capture any water that accidentally makes into the AC loop. Condenser: The condenser is basically a radiator, and it serves the same purpose as the one in your car: to radiate heat out of the system. The refrigerant enters the condenser as a pressurized gas from the compressor. The process of pressurizing the gas and moving it to the condenser creates heat, but air flowing around the twisting tubes of the condenser cools the refrigerant down until it forms a liquid again. Imagine steam cooling down and condensing back into water, and you’ve got the idea. The liquid refrigerant is now a high-pressure liquid and nearly ready to cool the car. Receiver-Dryer: But first, the refrigerant needs to be prepped for the evaporator. As it moves out of the condenser, the liquid goes through a little reservoir installed in the line. This receiver-dryer contains desiccants, small granules that attract water. You’ve seen packets of desiccants in shoeboxes, where they do the same thing: attract water from the air to keep new shoes fresh and ready for your feet. (They’re usually labeled “Do not eat.”) In the receiver-dryer, they remove any water that has entered the system. If the water is allowed to remain and possibly form ice crystals, it can damage the air conditioning system. That’s enough high-pressure for anyone, so let’s move on to the low-pressure side of the system. The Low-pressure Side  Thermal Expansion Valve (TXV): Here, the system changes from the high-pressure side to the low-pressure side. If you were to touch this part of the system, you’d feel it change from hot to cold. The high-pressure liquid refrigerant flows from the receiver-dryer through the expansion valve, where it is allowed to expand. This expansion reduces the pressure on the refrigerant, so it can move into the evaporator. The valve senses pressure and regulates the flow of refrigerant, which allows the system to operate steadily, but the moving parts of the valve can wear out and sometimes require replacement. Some vehicles have an orifice tube rather than an expansion valve, but it serves the same purpose in allowing the refrigerant to expand and the pressure to be lowered before the liquid enters the evaporator. The orifice tube allows refrigerant to flow at a constant rate and has no moving parts, but it can become clogged with debris over time. Systems with an orifice tube automatically turn the AC system on and off to regulate the flow of refrigerant to the evaporator. Evaporator: This is where the magic happens. While all the other parts of the system are located in the engine compartment, this one is in the cabin, usually above the footwell on the passenger side. It also looks like a radiator, with its coil of tubes and fins, but its job is to absorb heat rather than dissipate it. Refrigerant enters the evaporator coil as a cold, low-pressure liquid, ideally at 32 degrees Fahrenheit (0 degrees Celsius), which is why you don’t want any water in the system. The refrigerant doesn’t freeze at this temperature, but it does have a very low boiling point. The heat in the cabin of the car is enough to make the R-134a in the evaporator boil and become a gas again, just like water turning back to steam. In its gaseous form, the refrigerant can absorb a lot of heat. The gas moves out of the evaporator — and out of the passenger compartment of the car, taking the heat with it. A fan blowing over the outside of the evaporator coil blows cool air into the passenger compartment. The refrigerant in gas form then enters the compressor, where it is pressurized and the whole process starts all over again. If the system uses an orifice tube, there will be an accumulator between the evaporator and the compressor. An orifice tube sometimes lets too much refrigerant into the evaporator and it doesn’t all boil. Since the compressor cannot compress liquid, only gas, the accumulator traps any excess liquid before it can get into the compressor. The evaporator also takes humidity out of the air in the car, which helps you feel cool. Water in the air condenses on the evaporator coil, along with dirt and pollen and anything else floating around in the cabin. When you stop the car and see water dripping underneath, it’s probably the water from the AC evaporator and nothing to worry about. We’ve all heard about “recharging the A/C,” so we’ll take a quick look at that next. Recharging a Car’s A/C Most of us start seeing ads in the spring for car repair shops offering deals on recharging your car’s air conditioning in time for the coming summer. Which makes us ask, what is recharging the A/C? Is it required, like an oil change? Does my car’s air conditioning need to be recharged? Is this another scam that repair shops can pull on unsuspecting customers? The answer to that last one is definitely no; recharging the A/C is not a scam. It simply means that fresh refrigerant is added to the system. If the refrigerant is a bit low, it can be topped off, the same as if you were a bit low on oil in the engine. If it’s really low, though, whatever refrigerant is still in the system needs to be drained out and replaced. This process of clearing out the system and adding new fluid is called recharging. In either case, you’ve lost some refrigerant, which isn’t so great. Even though R-134a is better for the environment than Freon, the Environmental Protection Agency would rather not have any air conditioning refrigerant leaking into the soil and rivers. If you’re going to have the system drained and recharged, the EPA recommends having the technician take a look at the system to find the source of the leak and fix it. They don’t require the repair, but they’d really, really like you to have it done. This article has talked a lot about R-134a as a replacement for big, bad Freon, but there are others that have been approved by the EPA, too. R-134a has the distinction of being the refrigerant most tested and recommended by manufacturers, but there are others with names like Free Zone, Freeze 12, and Kar Kool that the EPA will allow in automotive air conditioning systems. Click Here to learn about the new refrigerant R1234yf

Cleaning the Condenser
Increasing AC performance by cleaning your condenser was a surprise to me. Eric the Car Guy turned me onto this. For those who don’t know He has Youtube channel and shows his viewers about the benefits of cleaning condenser coils. He says one of the biggest reasons that AC systems fail is due to increased head pressure in the compressor. Higher pressures equal more heat. The increased heat breaks down the lubricant. Once that happens, it’s not long before the compressor fails. One way to keep down compressor temperature is to lower high side pressures in the AC system. You can do this by increasing the condensers efficiency by cleaning it. Honestly, I was amazed at the result. This really works and doesn’t require that you open the AC system at all to do it. So if your AC isn’t working as good as it should, you might try this process to see if it helps. Click Here to see the Eric the Car Guy Video]]>

The importance of buying the right tires for your car

If you have never had to change the tires on your vehicle before, it can feel like quite a challenge if you don’t know what tires your vehicle needs. There are many factors to consider when it comes to changing your tires including price, brand, comfort, appearance, and safety: things that should all be on your checklist. If your car was brand new when you bought it, it is likely that the tires you need are the same as the ones you had to start with. This makes the job fairly simple; as you know which tires you need, the only other job you need to do is find someone reliable to fit them for you. Different vehicles are fitted with different types of tires that are specific to each vehicle. Factors depending on where you live, your typical weather conditions and terrain will all affect the type of tire that you need so it is important to ask a specialist about your tires, as they can advise you depending on all of the above factors. The cost of your new tires will very much depend on your vehicle and tire type. If it was used when you bought it, you may be able to find the name of your tires in your handbook. If you don’t have that information, it is a good idea to do your research before you jump into anything. You can find information from a local dealership or even through the internet. It is also important to check the tires when you buy a used car, as the vehicle could be fitted with the wrong tires so it is a good idea to replace them quickly with the correct tires. Knowing what tires you need is also important because it helps you for the next time you need to change them, meaning you can get replacement tires quickly. There are exceptions, however; some vehicles allow you to have different types of tires. It is important that you research beforehand and that you know for certain that they can be fitted to your vehicle safely. Your tires should be replaced when the tread falls below the legal minimum. In the U.S Most states require a minimum of 2/32 of an inch (approximately 1.6 mm) of tread. If you are pulled over by the police and they are below the minimum legal tread depth you could end up with points on your license and a fine. If they are not up to the standard it will also mean that your vehicle will fail its yearly inspection where it’s required by law. It is important that you carry out regular checks on your tires to make sure that they are in the best condition. These checks can be carried out at home and involve looking for bulges, scratches, general wear and tear and even objects that could have punctured the tires such as sharp stones or nails.]]>

Five ways to use a scope for diagnosing vehicles

Posted By: Albert Hammond – Written By Pete Meier For years, I was amazed at how few technicians I worked with had ever used a scope, let alone owned one of their own. In every shop I’ve worked in over the last 20 years, I was it. But I’ve been pleased to see that scope use is on the rise, as evidenced by the number of techs who raise their hands in the presentations I make around the country and the growth of online support groups – even on Facebook! And no matter the reason for the growth, I’m glad that more and more of you are seeing just how valuable this diagnostic tool can be. Here are a few of my favorite uses for the scope. I hope you find them helpful. As a note before we get started, I am going to share the scope settings I use. I admit I am no “guru” in scope use and learn continuously from those that are. I’m sure there are many of you who can offer advice on even more efficient ways of setting up and performing these tests, and I hope you will – in the comments section on MotorAge.com! The relative compression test Many years ago, I was tracking down the cause of a slight misfire on a Chrysler minivan V6. After checking fuel and ignition, I found myself having to dive deeper into the mechanical health of the engine. All of you know how time-consuming performing a conventional cranking compression test on a transverse V6 can be, and I also checked cylinder leak down on all six at the same time! Needless to say, I spent a few hours on the job that I never did get paid for. The relative compression test is a way of assessing the overall health of the engine with a lot less trouble and in a matter of minutes, instead of hours. It is one test I perform on every engine that I find myself troubleshooting a drivability concern on. Scope settings: Channel 1 – High current clamp attached to either negative or positive battery cable. Scale set to read to at least 600 amps to capture initial inrush current expected. Channel 2 – Standard lead or secondary clamp attached to cylinder ignition source (coil or secondary lead). Choose cylinder that is easiest to access. Adjust voltage scale to match connection and be careful to use attenuator if needed. Time base – 500 milliseconds per division OR 5 seconds total screen time Trigger – Single capture with the trigger set to rising slope and +1 amp. These settings allow me to capture all the info I need on one screen, and to do so without worrying about starting or stopping the scope manually. As soon as I turn the key “on,” the scope will begin to capture data. Figure 1 shows an example of what you can expect to see.  

Figure 1
The green trace is the current pattern captured. The focus is on the repetitive sawtooth pattern, where each peak represents the amount of current it took to push a cylinder through its compression stroke. Even on my old UEI scope, I could distinguish as little as a 10 percent drop in an individual cylinder’s compression using this method. In this capture, the cylinders are uniform in appearance. But remember, this is a “relative” view, relative to all the other cylinders. If there is a mechanical issue that is causing low compression across the board, you’ll see a very similar picture, with only one noticeable difference – the current levels of the peaks will be lower than you’re used to seeing on a healthy engine. I can also see that ignition timing appears to be OK since the ignition reference is intersecting the current pattern on, or just before, the peak. The spark occurs just before TDC, right?  

Figure 2

Figure 3
Take a look at Figure 2 for an example of a “known bad” capture. Though hiding behind the ignition reference, it is clear that the peak for that cylinder is not reaching the same level as the others. By following the firing order as shown in Figure 3, I know which cylinder I need to take a closer look at. With that information in hand, I have no problem going back to the customer and asking for the additional time I’m going to spend isolating the exact cause. Battery/charging system test A common reason I hear from techs who own (or have access to) a scope but don’t use it is the time it takes to set up. If you fall into that category, then let me ask you this. Don’t you turn the lights and coffee pot on every morning when you get to the shop? Don’t you start up the computer workstation you use so you can access your service information and workflow for the day? Starting up your scope should be on that same list of items, and if you use it to perform this next test on every car you get, you’ll also become more comfortable with the tool. A side benefit is that you’re performing a service for your customer that just might make you a little more money in the process. Scope settings: Channel 1 – Standard leads attached to battery positive and negative terminals. Scale set to read up to 2 volts per division or 0-20 volts total screen range. Channel 2 – High current clamp attached to either negative or positive battery cable. Scale set to read to at least 600 amps to capture initial inrush current expected Time base – 500 milliseconds per division OR 5 seconds total screen time Trigger – Single capture with the trigger set to rising slope and +1 amp. Figure 4 shows an example of a typical system test result. But for clarity, let’s break out the voltage and current patterns and review the key points individually.  

Figure 4

Figure 5
Figure 5 is the voltage alone. Just before “A” is the same Open Circuit Voltage you would read with your voltmeter, while “A” itself is the slight drop in voltage when I turned the key on. But I didn’t stop there, did I? I continued to the “Start” position and engaged the starter motor. “B” is the inrush voltage drop caused when the starter motor is just beginning to turn. After all, I have to get the starter moving and the starter is acting against all that mass in the engine. This loaded voltage reading is going to be lower than what you’re used to seeing when performing a conventionally loaded voltage test so rather than use the 9.5-9.6 limit you learned in school, use 8.5 volts as your minimum here. The time between “B” and “C” is the engine cranking. The little hills you can see are caused by the individual cylinders coming up on their compression stroke, just as we saw in the relative compression test. At “C”, the engine has started and is running on its own, with the key returned to the “Run” position. The upslope is the charging system replenishing the battery before settling on a more stable charging voltage at “D”. Now on Figure 6, the current pattern.  

Figure 6
As we saw in the voltage pattern, “A” is where the key is turned on and the scope starts its trace. As the key passes to the “Start” position, current flows through the solenoid contacts and then into the starter motor. Again, the inertia of the starter motor and the engine have to be overcome before it will begin to move and that brings us to “B” – inrush current. In this example, inrush current is reaching nearly 600 amps! But it’s only for a microsecond and is not an indication of any problems in the system. By now, you recognize what the peaks represent on the way to “C,” or the time the engine starts running and the alternator starts putting back what the starting system took out. Notice the short but rapid increase in current that quickly drops off and becomes stable. Since the current clamp is around all of the negative (or positive) battery cables, the current graphed on the screen represents “net” current flow; that is, the final total of current demanded by the system and the current being supplied by the alternator. This net amount will run around 3 amps or so. Any significantly higher amount should be cause for further investigation and may indicate a sulfated battery that is placing a burden on the alternator. Running in-cylinder pressure diagnostic This is one test that I truly believe was groundbreaking, changing the way we test engine mechanical systems forever. By adding a pressure transducer to your scope, you can now “see” the pressure changes in a cylinder throughout the entire 720° engine cycle – and with no more effort that performing a cranking compression test with a mechanical gauge. In Figure 7, I’m showing you a normal cylinder with the ignition and injector events included for reference.  

Figure 7
Scope settings: Channel 1 – Pressure transducer is connected to channel 1. Follow the manufacturer specific set up instructions for your scope. On this Pico, the transducer scale is selected from a drop down menu and in this example is reading -25 to +100 psi. Channel 2 – Connected to ignition event based on ignition system used by the vehicle. Channel 3 – Connected to injector event, by back probing ground side (control side) of the injector and using a 10:1 attenuator to protect the scope from voltage overload. Scaling is -100 to +400 volts to allow for the inductive kick of injector that occurs on turn-off. Time base – 20 milliseconds per division OR 0.2 seconds total screen time Trigger – Set to “auto”, rising slope of channel 1 with capture to begin at 4 psi. While this capture was taken using the Pico WPS500 transducer, there are others on the market notably those offered by Snap-on and Automotive Test Solutions (ATS). I have to offer props to ATS and its head, Bernie Thompson because I sincerely believe he is the one most responsible for bringing this test method to the industry. There is so much information in this one capture that I can’t begin to do it justice in this short space but luckily, Bernie has written a series of articles on this technique for us and you can access them all on the website. But to whet your appetite, consider that this method can find problems with poorly sealing valves, variable valve timing issues, timing belts that are out of time, and a lot more – all without tearing anything apart for a visual check. Think that will save you time? Fuel system testing The pressure transducer can be used for a lot more than in-cylinder testing, too. One way I like to use it is to deploy it on my scope for monitoring fuel pressure in place of my mechanical gauge. It allows me a quick way to check for injector issues that otherwise would take a lot of time to test. But I’m getting ahead of myself. Let’s get to the settings I use to capture the patterns you see in Figure 8.  

Figure 8
Scope settings: Channel 1 – Connected to injector event, by back probing ground side (control side) of the injector and using a 10:1 attenuator to protect the scope from voltage overload. Scaling is -100 to +400 volts to allow for the inductive kick of injector that occurs on turn-off. Channel 2 – Low current clamp wrapped around a “Fuse Buddy” that has been placed in substitute for the fuel pump power feed fuse in the junction box. Scale set to 0-10 amps. Channel 3 – Pressure transducer installed in fuel test port instead of a mechanical fuel gauge. Scale set to -25 to +100 psi. Time base – 50 milliseconds per division OR 0.5 seconds total screen time Trigger – Set to “auto”, rising slope of channel 1 with capture to begin at 50 volts. Testing fuel pump current has been around for as long as I’ve been using a scope but there are still lots of techs that have never heard of this technique before. The pattern shown is not clear enough for diagnostic use, so let’s take advantage of the scope’s ability to zoom in and take a look at the pattern shown in Figure 9. With very little effort we can see how much current the pump is drawing (a little more than 5 amps here) and what the speed of the pump is (roughly 5300 rpm). Consider that this approach works well on older style systems and you may have to adjust it a bit when looking at pumps that are pulse-width modulated. Even so, the pump is a motor, just like a starter motor, and it’s current will be impacted by the amount of work it’s doing – or not doing. And using this method beats banging on the fuel tank with a hammer!  

Figure 9
Consider a pump that has a low current draw and a high pump speed. That indicates a pump that isn’t working hard. Ever have a customer get towed in for a “no start” concern where his car said it had a half a tank of gas but it was really empty? How about the opposite scenario – where pump speed is low and current demand is high? That indicates a pump trying to overcome a restriction – maybe a clogged filter?  

Figure 10
On to Figure 10 for a closer look at the pressure transducer pattern. Notice the six lowest valleys between the injector events. We’re looking at a six-cylinder engine, and the injector pressure drops across all six injectors. How long would it take you to perform this kind of test conventionally? In this example, they all appear even so I don’t suspect a problem with a sticking injector. However, there are funny little squiggles on every other valley. What causes those, do you think? In this case, the three squiggle captures are all on the same bank and closest to the test port. This is normal “ringing” in the fuel line as each injector opens and closes. The rear are less so because the distance allows the rail to dampen the effect before it gets to the transducer. And No. 5 is… Actually, my fifth favorite test is any test I can perform with my scope that I haven’t tried before. The four examples I’ve provided are great examples of tests that once, had never been performed before! But some enterprising technician asked “What if?” and tried it. Now, they are all pretty standard for all of us! So ask yourself the next time you face a diagnostic challenge how you could apply your scope to the situation. And if you come up with something, let me know. I’d love to hear about it!
Article Source : http://www.searchautoparts.com/automechanika-chicago/commitment-training/five-ways-use-scope-diagnosing-vehicles?page=0,3
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