Giving vehicles the once-over

Jan. 1, 2020
In my automotive department, we do monthly inspections on all the college vehicles except the big busses. When I hand one of my students the job of inspecting a vehicle, it's interesting to note how serious some of them are about doing a really good

Thorough inspections benefit your customer and your bottom line.

undercar vehicle inspections automotive inspections repair shop training technician training A/C training automotive aftermarket In my automotive department, we do monthly inspections on all the college vehicles except the big busses. When I hand one of my students the job of inspecting a vehicle, it's interesting to note how serious some of them are about doing a really good job and how totally bored some of them are at having to run through the inspection checklist on a car we just inspected the previous month. But vehicle inspections are like insurance, and we should see them from that perspective. We do them to prevent dangerous or expensive failures.

But when the shop is busy and there are gravy jobs waiting, some technicians will blow by a few inspection items without consequences, and that behavior breeds more of the same. That mindset potentially can lead to disaster.

Case in point: A woman I know bought a used 2010 Ford Fusion from the local GM dealer. When she took it back a few days after the purchase complaining of an intermittent popping noise in the front end, they told her to take it to the Ford dealer because it wasn't their product. She brought it to us instead (the Ford dealer was many miles away), and we found a lower control arm bolt that had loosed itself from its threads and worked its way almost all the way out.

Had that very important bolt finished its trip to the pavement, well, finish the thought. A simple vehicle inspection with a good bright light would have revealed that problem, even to a GM technician. After the possible crash, that failure would have been very easy for an insurance inspector to hang the blame on whomever checked the boxes on the vehicle inspection checklist.

I placed a meticulous female graduate of mine at a local dealership, and one of the first things she noticed was how the other guys in the shop weren't doing the required vehicle inspections right. While some customers don't give a thought to anything except what they told the service advisor during the write-up, many customers expect a thorough tally of their car's health. But too many technicians just check off the boxes and hope nobody finds something among the items they chose not to check.

If the customer discovers the missed concern, it might well be in a bad part of town or on a rainy interstate at 80 mph. Techs tend to get bored with vehicle inspections if everything checks OK on several cars in a row. Even if they do find concerns and they have a run of customers who don't buy the extra work, it feels like they're giving away their labor for free on inspections. Those of us who have worked on commission can understand how they might feel about that. Some shops offer incentives for upsell, and that tends to help, but no system is perfect in a shop with 25 technicians. Then there are the ones who believe they're too good at their specialty or too busy doing "real work" to do a vehicle inspection on every car.

I knew one guy who had to do some inside work on the steering column of a vehicle then checked off all the inspection points before he turned in the ticket, having never opened the hood. When the customer came to pick up the car, the battery was weak, and when the hood was opened to apply the jumper cables, there was a squirrel's nest on top of the battery. Can anybody say, "Busted?" A half-baked vehicle inspection is no laughing matter and can lead to disaster. Just about all of us could tell some stories, couldn't we?

How Deep Should We Go?

You can do a cursory inspection, but we're talking about a really good one, so let's go for broke. Some of you guys and gals will probably think of something I'm going to miss. Write to me if you do. While you can do the following in any order, I'm putting these checks in the order that make sense to me. It makes sense to have an inspection sheet with a list of checks along with adjacent green, red, and yellow boxes and comment lines.

It's best to start an inspection with a cold engine whenever possible, because we'll be touching some things with our hands. Heating the engine will come later in the inspection. First, do a walk-around, then operate the keyless remote. Does it chirp the horn, unlock and lock the doors, and does it pop the trunk? Have a look at the spare if it does. Many cars are driving around with flat spares. Confirm the presence of the jack and lug wrench.

Pop the Hood

Under the hood, we need a really bright light (in my opinion, a strong flashlight is better than a droplight for this). Begin by looking for fluid leakage, including greasy areas around the plumbing that carries refrigerant. We do the obvious fluid level checks, and if we really want to be thorough, we check the brake fluid for moisture and copper content. Both are indicators of fluid needing replacement, and can save your customer a ton of money in the long run by preventing corrosion damage to parts that cost a lot more than a fluid flush.

Inspecting the coolant for obvious rust and contamination is another necessity. Pay good attention to the radiator cap and the hoses — any rubber coolant hose that is near an oil leak area should be replaced if it's greasy. A voltage test on coolant is a good test. Measuring between battery ground and the coolant, we shouldn't read more than 0.5 volt, which is a borderline reading, and I'd flush one that gives those numbers. Less than 0.2 volt is really good. A 0.7 or higher reading is deal breaker and calls for a cooling system flush.

During this process, it's good to see if we can find any disconnected engine to body ground straps that might be the cause of the high voltage readings. Testing the coolant with a refractometer is a must, and if battery electrolyte is accessible (on many batteries nowadays it isn't), we can check that while we have that tool in hand. The battery itself should be checked with a professional grade tester, and it's best to remove the battery terminals to test the battery, but take measures to save the memory else you may be scrambling for a radio code on some cars.

As for the belt(s), Dayco and Gates both have neat little plastic tools for checking serpentine belt wear. The belt can be worn out, even if it isn't yet cracking and it's wise to obtain one of those tools (usually you can get one for free from your parts store). Any belt that is saturated with coolant or oil should be replaced, and the source of the contamination should be investigated as well. Don't forget to put your hands on the belt tensioner, water pump and/or idler pulleys to see if their bearings are tight. Some water pumps are inaccessible, and on those, the weep hole should be examined with a flashlight if possible.

Wire harness and hose routing should be checked. A harness or hose that has come free from its anchors should be noted and, depending on circumstances, rerouted and/or reattached. Notice every connector to make sure it's seated. Spring type coolant hose clamps sometimes crack so those need to be inspected as well.

Raise It

It's difficult to do a good inspection with all the wheels on the ground, so after you've determined that the car sits level, get it in the air with the wheels chest high. Tire pressure and tread depth are important and those numbers aren't hard to get. Spin the tires and listen for noises. Look for loose or missing lug nuts, yank the wheels (sometimes lug nuts will seize coming off and you'll find them this way) and inspect all the brake pads — inner and outer — because sometimes one pad will wear down to the metal while the other one looks pretty good.

If the vehicle has drum brakes on the rear and you can get the drums off fairly easily, put on a breathing mask and have a look at the shoes. If they're greasy and wet looking, you need to determine whether the wet stuff is differential grease or brake fluid. I like to wash the brake dust off (don't blow it!) before I put the drums and wheels back on. Lugs should be properly torqued to specs when the car is back on the floor, so have your torque wrench ready.

Raise it the rest of the way and walk under the car for a good look at what can't be seen otherwise. If you see oil dripping anywhere, get some on your finger and try to determine where it came from. Everything that has fluid in it is a potential leak source. If a gearbox (transmission or differential) is leaking, have a quick look at the vent. If it's clogged, that could be the reason for the leak.

The exhaust system can be smoke tested for leaks if you're a stickler, and every hanger should be inspected. Rusty mufflers and missing catalysts should be noted as they are discovered. Shock absorbers shouldn't be leaking or loose, and steering parts should be good and tight, without busted boots anywhere. CV axle boots should be intact. Suspension springs should be examined for cracks. The other suspension parts shouldn't be bent or rusted to the point of failure, and there should be no loose fasteners. Sway bar links should be in good shape.

Now let's get the wheels back on the concrete, torque the lugs to specs and have a look inside. Unless we found a safety issue underneath, we'll drive it.

In the Cockpit

In the driver's seat with your scan tool handy, link it to the DLC and check for pending trouble codes, then menu into the datastream to watch the engine warm up. The O2 sensors should behave correctly and the fuel trim numbers should be acceptable. The engine temperature should rise steadily and then drop slightly when the thermostat opens. The radiator/condenser fan(s) should come on and go off.

Now let your fingers do the walking. Check the door locks and windows for proper operation. Fire up the radio long enough to see if there are any speakers rattling, then shut the radio off. See if the tilt wheel works. It's a no-brainer that the gauges and lights on the instrument cluster and panel should work. If you don't have shop mirrors, have an assistant check the exterior lamps while you put them through their paces. Notice the high beam and turn signal indicators.

With the engine fired up (listen for starter operation that sounds normal), exit the driver's seat to stand over the engine and listen for any unusual noises, including noisy accessory components. Does it idle smooth? Does anything in the belt-and pulley area wobble? It's at this point that the transmission fluid needs checking, but be aware that it'll read lower cold than warm. If this platform has a cabin air filter for the A/C, yank it with everything shut down and have a look at it.

Warning indicators (MIL, ABS, Air Bag, audible alarms, etc.) should be investigated if they're issuing warnings with the engine running. Blow the horn and wash the windshield, looking for chattering or shredded blades that don't squeegee the glass right. Do the wipers work on all speeds, including intermittent? The HVAC controls should be run through their paces (including all the blower speeds) to make sure the air goes where it should, and the A/C should cool well. A stickler might want to hang the A/C gauges and look for acceptable pressures and temperatures. Have a good look at the seat belts, sun visors, upholstery, headliner, interior lights, all the mirrors (electric and otherwise) and so on.

Feel the brake pedal: Is it mushy or does it fall away (fade) if you leave your foot on it? Check the parking brake; it should keep the car from moving forward when it's engaged.

Put the car in gear: Does the shifter feel right? Drive it out of the shop: Do you feel the telltale "thunk" of broken mounts? Put on your sunglasses and take it down the road. You should go at least 10 miles, obeying all traffic and speed laws. The temp gauge should read nice and warm. We know how the car should accelerate, that it shouldn't vibrate, how the steering should respond and how the vehicle should feel when cornering. Every technician can drive a car and tell when something isn't right, and a test drive should be done without the radio on and with the A/C blower on low so as to listen for unusual noises.

Transmission operational checks are a must. Cancel the overdrive and see if the rpm increases. Check the cruise control functions and see how the brakes feel when you stop. Do they pulsate or make noises?


One more walk-around and the job is done. This inspection was a good one and would probably take most of an hour, but a person who does an inspection like this and takes it seriously will sell a lot of work and provide peace of mind that simply can't be had any other way.

Richard McCuistian is an ASE-certified Master Auto Technician and was a professional mechanic for more than 25 years. Richard is now an auto mechanics instructor at LBW Community College/MacArthur Campus in Opp, Ala. Email him at [email protected].

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