by Sam Dillinger (comments: 0)

Selecting replacement auto parts

replacement parts

This topic seems pretty straight forward on the surface of it: when you've determined what’s wrong with your car, or what’s broken, you call a few places, pick the cheapest one, and go get your parts. Simple, right? Actually, no. Let me explain.

First, it depends on if you're repairing your vehicle yourself. If you’re not, then, generally speaking, go with the recommendation of the person who is doing the repairs. Independent repair shops, and even dealerships, will install the parts that you bring them, but it drastically changes what they will do for you as far as warranting that repair in the future. They won’t warranty the labor for the repair if you bring them parts from an outside source, and they usually leave the parts warranty onus on you, meaning that you’ll have to pay them to remove the defective part, then they give it to you. Then you have to go back to where you got it from and get the replacement part, go back to the servicing repair center, and pay them to install the new part. For these reasons, if you're not repairing the vehicle yourself, I recommend just going with the advice of the shop you're at, if just for convenience alone.

For the DIY crowd out there, let’s take a look at the options, and how to pick the best source for your parts. Traditionally the choices were either the local parts store, or the dealer. Now the internet gives you a great tool to get the parts you need at a much more palatable price. Whether it’s from a dealer, or from the local Autozone, they are the middle man in the distribution chain for parts. Any time someone else gets the chance to handle the parts, the price goes up! However, there are times that each of the 3 options are the right option for you. Let’s take a look at each.

We’ll start at the top of the food chain: the dealership. These are the parts made for the manufacturer and installed on their vehicles when built. These are the parts that you can buy over the counter in their parts department, or while having your vehicle repaired in the service department, and will be the best, but most expensive option. An important note here: there are certain parts that can only be purchased NEW from the dealership. You might be able to find an aftermarket source online for one of these parts, but it won’t be the original factory part and the quality could be insufficient, or even downright unacceptable, for these kinds of parts. So, where were we? Right, dealership parts. They’ll come with a great warranty and they've got a nationwide network of servicing Parts Distribution Centers, as well as all the other deanships that stock parts as well. This all means that, in most cases, the parts you need are readily available that day, or the next. Availability of the parts you need is a huge factor and not to be understated, especially if you do it like I have a million times and take your car apart before you see if they have what you need! The only real downside is the price. Purchasing the parts at retail price from the dealership will be the highest you’ll pay in almost every instance.

Next is the local aftermarket parts store such as Autozone, Advance Auto, and Napa, to name a few. These guys can definitely save you a lot of money, especially on things like brake pads and rotors. For most passenger cars (non-luxury cars) you can get a set of brake pads and both rotors for the front or the rear, for $60-$80. Compare that to, in some cases, $80-$100 per rotor at the dealer, and you can see that it’s worth your time to go aftermarket for these parts. These parts stores carry much more than just brake pads and rotors, even offering transmission repair parts, and most everything in between. The issue with buying some of these parts comes from the quality of the manufacturer, not the store selling them. In particular, I’m talking about the electronic parts. Things like the Powertrain Control Module, fuel injectors, and oxygen sensors to name just a couple. Don’t get me wrong, these stores sell good quality electronic parts, but in this article we’re focusing on the most cost effective parts. If your car is made with Bosch fuel injectors, and the aftermarket store carries a Bosch brand fuel injector for your vehicle, this will be a quality replacement part, but it won’t be the cheapest one. That’s where the trouble can come in. For the electrical items on your car, buying the cheapest one available is risky at the very best. In all my years fixing cars I’ve never had a cheap PCM be trustworthy. Not once. So for things like brakes, rotors, belts, thermostats, hoses, water pumps, etc. these stores are fantastic and will give you a great savings. For the electrical parts, if you choose to go to the aftermarket stores, be sure to buy the part made by the original manufacturer for your vehicle’s parts, but overall I’d recommend going to the dealer for those particular parts.

Last is online. This has a lot of similarities to the aftermarket parts stores with one notable exception: in a lot of cases you can buy directly from the part manufacturer, or a wholesale distributor, and get the parts at a significant discount, even over the cheaper prices of the aftermarket parts stores. One source that I’ve used with great results is These guys have a really great catalogue of parts, offering most of the top aftermarket name brands, as well as other brands with less notoriety. For example I recently had to replace both lower control arms on my son’s car (my kids lucked out. Car repairs for them cost way less than it would for most people, and they aren't shy about coming to me regularly about having “this weird noise” or “that thing it does sometimes and I don’t know why”) and I went to a local parts store to get a price. They were selling both of the control arms for roughly $75 each plus tax and I could have them the next day. That’s a fair price when you consider that a control arm with the ball joint built into it, and both bushings already installed, regularly costs in the $300 range per control arm! I was comfortable with the $75 per control arm cost but decided to check online to see if I could get a better deal. I was able to get Moog control arms for $41 each plus tax and shipping, which came out to a total of $94.57. They came in very quickly (I ordered them on Monday evening and had them on Friday afternoon) and the total price even with shipping was $64.43 cheaper! The main caveat of buying parts online is that you have to know exactly what you need because there won’t be anyone there to ask questions of. I had to buy a crankshaft position sensor for my son’s car as well and they're are 2 different styles. If you don’t know which one you have, this method isn’t going to be best for you. As far as a warranty goes, the parts you buy will have whatever warranty comes with the part from the manufacturer of that particular part. The other caveat being that you’ll need to be able to wait a couple of days to receive your parts. Overnight shipping is available for a lot of the parts but, for heavier parts at least, the overnight shipping option will make it much less of a bargain, if not end up costing more than a local parts store.

So where do you buy your parts? The answer is that it depends on the parts you need and who is fixing your car. For my DIY readers, make sure you research online parts sources before just popping into Napa and picking up what you need, you could really be missing big savings. For the folks who are having their cars worked on at a shop, make sure you mention places like to help with savings! As always for my members, feel free to send me an email from

and I can help steer you in the right direction.

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Meet Sam Dillinger

My name is Sam Dillinger. I've been a professional, dealership technician for 18 and a half years. My first introduction to mechanical repair was when my own vehicle broke down in the fall of 1995. I was 18 and couldn't afford to pay to have it fixed. So I borrowed tools and asked a ton of questions and, eventually, was able to replace the clutch on my truck by myself. During the course of that project, I found that I really enjoyed having a wrench in my hand and figuring out the puzzle of disassembly and reassembly of a motor vehicle.

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