You can save serious money if you pull car parts from the junkyard rather than buying them brand new. Of course, you’ll need to make sure those car parts work first, and that’s where we come in. Read on for our guide on how to test car parts commonly pulled from the junkyard.
When replacing an engine part that you got from the yard, it’s important to determine which motor your car has. You won’t always find your motor in the same chassis. For example, you can find the 1.8 Turbo Volkswagen motor in different Volkswagens as well as Audis. Just like you’ll find the 642 Turbo Diesel motor in the Mercedes-Benz Sprinter and a few Mercedes SUV models.
It’s also vital to know what your car’s chassis is when replacing parts on the body. A lot of auto parts will have a part number written somewhere on the part. You are always better off locating that number and verifying it!
Quick Tips Before Installing Pulled Car Parts
Now, you may be excited to finally use all those bargain car parts you pulled. Before you we dive in to the good stuff, here are a few really good tips to know before installing.
- First, it is always a good idea to spray alcohol on electrical connectors. It’ll make them easier to remove and to clean.
- Clean up an electrical connection with dielectric grease.
- Always test fuses, relays, and faulty voltage supply first on electrical parts.
- Keep in mind that you can rethread a bolt or fitting that has been stripped.
- It is always good to bring a battery or something to produce voltage to test with.
- Bring out your car’s service manual! It’ll be a useful reference when repairing parts.
- Arm yourself with a sufficiently bright flashlight when examining, diagnosing, and repairing your vehicle.
- Sometimes, it’s easier to install a part on your car first to see if it works or not.
- Here are things you should ideally buy new: cabin, fuel, and air filters, drive belts, most all gaskets, all fluids, and other parts as well. Use your best judgement or ask someone with experience.
We’ll start with tips for common engine parts, and end with parts from the chassis.
Power Steering Pump
Inspect the body of the pump for leaks. Check for leaking in the power steering lines. A lot of the time a power steering pump will leak from the hose fittings. It doesn’t necessarily mean the actual pump is bad – sometimes you just need to do a quick reseal. Spin the wheel of the pump to ensure a smooth, consistent rotation. Check for excessive amounts of sound or a loose wheel; these are signs of a bad pump. After installing, if the pump makes loud noises, or the steering doesn’t function, the pump you pulled could be bad.
Power Steering Lines
Inspect threads for signs of stripping or worn o-rings. Look for crimps in metal portions of the line, and deterioration from excessive heat or ozone in the rubber portions. Make sure to replace seal rings before installing old lines onto your car.
Check for leaks coming from the body of the rack and the gaiters. Examine band clips to make sure they are not too tight or too loose. If the gaiters have damage, replace them before installing. It is difficult to know whether the steering rack is good without disassembling. However, you can test its function simply by installing it on the car. Check if the steering wanders or if there is play in the steering wheel. Also watch out for grinding noises or leaks. If there’s any of these, replace the rack with a better or new one.
Air Conditioning Lines
Look for obvious leaks in the line by identifying dried up refrigerant spots. Locate the high and low pressure valves and unscrew the covers. Press one of the valves down with a pocket screwdriver to see if the system is pressurized. If so, don’t remove the lines without depressurizing the system. Be sure to replace o-rings and seals before reinstalling.
Visually inspect the fins of the radiator for damage. Don’t use a radiator that has corrosion or dents. After installing the radiator on your car, carefully check the temperature of the engine to prevent overheating. Note that if the car is overheating but not leaking coolant, your problem could be the thermostat or temperature sensor.
Turbo and Parts
Inspect the body of the turbo for cracks. Holding the turbo in your hand, reach and spin the turbine inside. If it spins smoothly and with ease, the turbo is likely still good. It is smart to replace every seal when putting the turbo back on. This is so that it’ll be easier to avoid unwanted check engine lights and leaks. Losing coolant and oil from the turbo is a quick way to destroy your motor.
Sometimes you might have a charging problem with your alternator. First, check your drive belt to make sure that it is not worn out, or too loose. If you don’t have a multimeter to test the charging power of the alternator, go to any local auto shop. They’ll easily be able to tell you whether it is functional before installing.
Inspect all locations of electrical connection. Make sure there are no broken teeth on the pinion gear. Clean electrical connections if necessary. You can easily test the starter function with jumper cables, a battery, and something metal, like a screwdriver. Connect the positive to the larger, positive threads on the starter solenoid, and the negative to the body or ‘ear’ of the starter. Then, secure your starter in a vice, or simply pin it down with your foot. With a screwdriver, create a connection between the positive connection and smaller spade connection. If the starter does not turn, it is a bad one.
Electronic Control Unit
A problem with your ECU can be a very difficult one to pin down. If you are ambitious, you may search for procedures on how to test continuity, and certain testing procedures to your motor electronics. The ECU is a VIN specific part. This means that it almost always needs to be reprogrammed before use in a different vehicle.
Make sure coolant hoses have no holes in them and are still relatively firm when squeezing with your hands. If the coolant hose is soft and squishy, save yourself some worry and buy a new coolant hose. If it is a metal coolant hose, make sure you replace the seal when replacing on your car.
Blow through the tubing and feel for solid air flow. Now, blow through again, putting your finger on the other end to block the air flow. Make sure there are no leaks.
Inspect electrical connections. Apply both sucking force and blowing force with your mouth, to see if the valve still functions. If you can blow one way and can’t suck— or the other way around— the valve itself is still functioning. Clean carbon deposits with brake fluid and a rag before reinstalling.
Check for kinks and carbon deposits blocking the passage way. Blow through with an air compressor blower attachment to check for clear air flow. Clean electrical connections with alcohol.
Look for dings and blemishes on metal pipes. It’s best to clean any existing oil out of a charge pipe. Any soft material air pipes, like an intake air hose for example, may tear easily. You may just want to buy one brand new to be safe.
You can test the resistance of a fuel injector by using a multimeter. After unplugging it from the wiring harness, put a test lead on each electrical pin. Each injector should have the exact same amount of resistance when tested. Look up the spec for what the correct resistance is for your specific automobile. It’s also wise to clean an old fuel injector before installing it back in to the car. Do this by using the method of applying voltage and flushing it with carb cleaner.
Inspect the spark plug visually to insure there are no cracks or deformities in the crush ring. If the downward faced tip is covered in oil or has corrosion, it is likely to be fouled. It probably won’t perform well and may not even produce spark. It is important to torque a spark plug to spec upon replacing, as well as gapping correctly with feeler gauges.
If you are pulling a whole motor from the junkyard, check for a few things before taking it home. With a socket wrench (ideally 1/2”), crank the motor around clockwise (as if you were tightening) on the crank pulley. Check for a smooth rotation of the motor. Does the crank pulley turn at all? If it is difficult to turn, it is very possible that the motor is seized or will not function. Examine the overall cosmetic condition of the motor, check for leakage points, and broken pieces.
Check the fluid level by removing the fill plug, and dipping a finger inside, to see that there is fluid. Shine your flashlight on a sample of fluid to make sure there are no shiny chunks of metal. Examine linkages to ensure they are functioning properly. You can do this by sitting in the car and switching between gears when the car is off. However, you won’t know whether it’s a good manual transmission until you have installed it and the engine is running.
It’s pretty impossible to know if an automatic transmission is good or not without taking it apart or driving it. However, it is best to make sure that there is nothing broken on electrical connectors and linkages. These are crucial to the function of the transmission.
Check the condition of spring mechanism for consistency by twisting the part where the cable hooks on. Examine the throttle plate to ensure it is opening and closing properly. Clean electrical connectors with alcohol. Examine the throttle body stop screw and idle adjust screw. We recommend cleaning with a can of throttle body cleaner.
Mass Air Flow Sensor
Without the engine running, it will be hard to check the functionality of the mass airflow sensor. Make sure the electrical connector is undamaged and without corrosion. Before installing, it’s good to spray mass air flow sensor cleaner inside of the MAF, where the hot wire resides. It’ll ensure proper functioning.
Inspect manifolds for cracks. Always replace gaskets when reinstalling. If the intake or exhaust is dirty, put the manifolds in a parts bath for cosmetic and airflow improvement. In some rare cases, manifolds have moving parts. If this is the case, refer to a service manual for proper maintenance of that certain manifold.
The fuel system can sometimes be a tricky one to diagnose, but the fundamentals are quite simple. There are many different types and styles of fuel pumps. Do some research as to which type of pump your vehicle has. Remember to check simple things first, such as any fuses or regulators that are associated with the fuel pump. After you have pulled a fuel pump from the junkyard, make sure it is free of corrosion. Once you have installed the pump on your own car, you can run a fuel pressure test by connecting a fuel pressure gauge to the fuel pressure testing port. Additionally, test the voltage to and from the pump with a multimeter.
Use a tread-depth gauge to get a good idea of how much life the tire has. Flex the tire and check for softness. A sign of a good tire is that it’s firm to grasp. If the tire is excessively soft, don’t use it. Inspect the inside and sidewalls of the tire for punctures. If the tire has a puncture, but it’s relatively small, and not close to the sidewall, it is possible to use a patch or plug to repair the seal. Lastly, make sure the tire is the right size for your vehicle. Often, you can find the sizing on the sidewall of the tire.
Visually inspect the wheel for damage, especially on the outer rim, where the tire will seal on. If the wheel is dirty around the sealing edge, clean the surface with a wire brush attached to a drill. It’s especially useful for chrome wheels. Once you have mounted a tire on the wheel and inflated it, check for leaks with a spray bottle full of dish soap and water.
Generally, you should buy brakes brand new to ensure the quality of function. However, if you are in a pinch, make sure that the rotor has enough material on the face where the pads will touch. Also, make sure there is not an excessive amount of rust on the rotor. When taking pads, make sure there is enough thickness on the surface of the pad that touches the disc. Taking old brake discs to a local auto shop to be resurfaced is never a bad idea.
When examining a used control arm, the most important part is to make sure there are no large cracks or breaks in the rubber bushings or ball joint. If the rubber seems well preserved and there are no fractures in the metal, the control arm should be safe to use on your junkyard build.
Light Assemblies and Bulbs
For the light housings, it’s important that the plastic isn’t broken, and that the electrical connectors are clean and snug-fitting. When you open the cover to take the bulbs out, check for the seal that prevents condensation inside the unit. For the bulbs, a simple tungsten bulb is easy to inspect. Simply hold it up and look to see if any filaments are severed. However, halogen headlamps are a little bit more difficult to inspect. You should never touch the glass part of the bulb with your fingers. Why? Because doing so will cause a heat spot causing the halogen lamp to burn out prematurely. Visual signs of a bad halogen bulb include a smoky black color of the glass, and bubbling or cracking. You can also test the continuity of the bulb with test leads to make sure continuity exists.
The easiest visual sign that a strut or shock is bad is if there is hydraulic fluid leaking out. Your best bet is picking the newest or best condition car in the junkyard to pull the suspension out of. After installing the junkyard strut on your car, you’ll know how drastically you have improved the suspension simply by driving it over bumps. See how well it performs. You can also jounce each side of the car physically to test firmness.
The visual signs of a bad coil spring include excessive rust or wear. Once you install the junkyard spring, listen for any noises coming from the suspension. Check for vehicle sag when parked and vehicle sway when turning. If you are still bottoming out over bumps after spring replacement, you may want to consider replacing the shocks.
Just like with the coil springs, inspect for signs of corrosion. If there is slight rust or dirt in between the spring leaves, clean it with a wire brush. Then wipe clean with a wet rag. After cleaning, you can lubricate with a silicone-based lubricant. While cleaning, check that the U-clamps are tight and in the right position. Check the conditions of the clips holding the leaf springs together. Ensure that the shackle and dowel pins are not bent or corroded. Check rubber bushings at the end of each leaf spring. At most junkyards, the vehicles are no longer supported by the suspension. You will have to use your best judgement based on the cosmetic condition of the spring.
Window regulators are always a great find at the junkyard. If you can easily access the positive and negative sides of the cable coming from the regulator, you can test its function by applying 12V using either jumper cables from the battery or an external source.
Check the overall functionality of the switch. Make sure it clicks up and down like it’s supposed to. You can also test continuity of the switch by using test leads and testing each separate terminal for continuity with each separate function of the switch, according to the service manual. Keep in mind that no continuity exists if the switch is not pressed down.
Blower motors can be easy junkyard pulls that can give relief if your heat or air conditioning has gone out. Test the blower motor by applying 12 volts to each wire connector. It does not matter which way you apply the voltage, as the rotation of the fan will just reverse. Note that your problem could also be the lack of voltage supply or a faulty resistor.
Blower Motor Resistor
Usually when your blower motor goes out, it is just the resistor running alongside it that is bad. Testing procedures require that you test resistance between the two terminals. Each resistance of each automobile is different in specification. However, if the circuit remains open, with an infinity reading on the Ohmmeter, the blower resistor has definitely gone bad.
Lock and unlock switches go through a similar test as the window switches. Check for continuity between the different terminals for each function of the switch, using the service manual as reference.
Examine the function of the door lever as well its cosmetic condition. After removing the door panel, make sure that the pull rod is connected to both the door lever and latch. Ensure that no small plastic parts are broken.
Door Lock Actuator/Door Latch
Open and close the door, testing the function of the latch. If the car has door lock actuators, this is one case where it is easier simply to replace the part. You can then test it newly replaced within the car. It is possible, however, to disassemble the actuator and look for broken parts or find a severed or corroded solder.
Hood Lift Support Shocks
Check the function of the shock. If the shock goes up but it no longer supports the hood, it’s no good. Support shocks are easily removed by pulling the clips out on each end with a pocket screwdriver. Pop it out of place using a firm hand.
Inspect the axle for rust, grease leaks, and torn axle boots on cv axles. After installing, test the axle by first raising the car off the ground. Watch the axle spin while someone holds their foot on the gas pedal to check for trueness.
Looks for signs of fluid leaking from the differential. Unscrew the fluid fill bolt on the top and dip your finger inside to see if there is fluid. If there is, examine the fluid to ensure that there are no tiny chunks of shiny metal.
There you have it. An exhaustive list of ways you can test commonly pulled car parts at the junkyard. Sure, you may score great bargains for the parts you pull, but are they functioning as they should? Or are you better off buying brand new? Doing the inspections above can help you distinguish between a decent find and a piece of junk.