So you decide that you want to buy a car in order to sell it for some well-earned profit. Perhaps you just want to buy the car for your own personal gain. Well, how do you know if the car is worth the buy? You don’t, that’s the problem. You are constricted and stuck with what the seller wants you to believe. You can ask the seller to turn on the car, but that isn’t enough. There is one simple test that can change everything. It can mean the difference between having to repair the whole car and driving thousands of miles without a problem.
What many people don’t share around is that there is an easy method to tell if the car is worth buying. It will require a bit of studying, as you’ll need to identify a few components and have some tools. Having years of expertise in the automotive industry, allow me to enlighten you in the path to success.
Things you’ll need:
- Vacuum Gauge
- The Seller’s Cooperation
Step 1: Inform Yourself: The Engine Vacuum Test
The basics are this: the engine both compresses and creates a vacuum in order for the whole system to function. The Engine Vacuum Test can tell you the overall condition and life of the engine. It is a great and inexpensive way to find a vehicle with a great engine that won’t die off of you rather quickly. Many people make the mistake of not checking the vacuum of the engine. The main problem with not checking the vacuum is that they are risking having to repair the engine, which could cost a very large amount of money! Any kind of engine failure can result in a bad engine vacuum, meaning you could have an insight whether the engine has lots of life in it and whether it would cost you maintenance in the near future.
Step 2: Locate the Intake Manifold
Go ahead and look at your engine — yes, that big piece of metal in the center if you honestly didn’t know (which is fine, as most people are clueless and it isn’t anyone’s fault anymore). This is where it’ll take a bit of studying. Depending on the make and model of the car, the Intake Manifold can be anywhere. On a Kia Spectra the intake manifold is found right on top of the engine on the far side of the engine under the hood. It’ll look like ribs. Careful, it might be hot!
Another recommendation would be to just simply find the location of the intake manifold online for beginners. After a while, you’ll be able to find it on your own, as car components will be put on different places — even look different — but you’ll be able to identify them all just by looking around.
Step 3: Disconnect the RIGHT HOSE
There are two hoses: one that is really small, and one that starts out a bit bigger but if you follow it, it’ll expand and become bigger. You are going to remove the smaller hose. Once you disconnect that hose with your pliers, continue to the next step.
Step 4: Connect the end of the Vacuum Gauge into the opening left after removing the hose.
Ask your partner (or the seller) to step into the car. He will have to turn on the car.
Last and Final Step: Record the results!
Once the car starts running, wait a few seconds. The vacuum gauge will start to show readings in Hg (Mercury) in inches. The reading should be inbetween 16 to 18. If it is any higher, that is fine. The higher the better. It is very rare to have a very high reading, but it is definitely possible. Record the reading at idle on a piece of paper.
Next, ask your partner (or the seller) to increase the rpm to about 1500 or 2000, depending on which one really would make sense to you. Record those readings again. If the results are lower than 16, it is worth noting that the engine will die off soon and isn’t worth buying. If it is 16-18, the engine has a good amount of life left if it is well maintained. Any higher would mean that the engine is performing extremely well, so it should be a definite buy!
Before you finish, take note on whether the Vacuum Gauge reading was easy to read or not.
Was the reading easy to read and stayed steady?
If yes, then great job! It is a great car to buy! If the reading was also 16-18 or higher, it is good to go!
Was the reading very difficult to read because the stick was moving back and forth repeatedly between the same numbers i.e. 16 and 18?
This is occasionally a problem, but it should all depend on whether the reading stayed within specifications (16-18 or higher). If it was lower than 16 and it had this type of reading, DON’T buy the car. This means that the car might have a sticky valve, a vacuum leak, etc., and it’ll cost you money and time to get the problem fixed.
This is the end of this guide. I hope It will serve well for you. As for any and all car endeavors I always recommend having a car repair manual handy!