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Spring 2023

A newsletter brought ot you from Len’s Auto Repair.

A Little History…

Every few years, we like to tell the story of Len’s Auto Repair and how it came to be. We do this because we want all of our new customers to be aware of our story, and we want our current customers to remember the fun our dad had running his business.

On March 4, 1974, Leonard Mertz began what has now become his legacy. He purchased an old three bay gas station in Overland and opened Len’s Auto Repair. For the next 32 years, he worked tirelessly to build a solid reputation for quality auto repair and honest automobile advice.

In the beginning, Len worked alone, but eventually his sons, Kim, Jon, and Greg, joined him in the business as mechanics, then service advisors, then eventually becoming owners. Greg’s wife Marit exited a teaching career to oversee the business operations.

In 2003, the original Overland shop was torn down and a new six bay building was constructed. In 2012, a second location was opened in Cottleville. This new location eventually was transformed into ten bays in 2017. We then built and moved into a new twelve bay Cottleville shop in early 2022.

In late 2020, we opened our third location in North O’Fallon featuring six bays and have been steadily growing. Len’s Auto Repair continues to be known as a neighborly repair facility with exceptional technical expertise.

It is a place where customers can get their vehicles repaired by honest technicians, and have their tires inflated or fluids checked at any time.

We are grateful for the privilege of serving the Overland, Cottleville, and O’Fallon communities still to this day. We look forward to seeing you in the future at one of our shops!

Leonard Mertz Working On A Car


A/C Performance Check

  • Perform a baseline checkout of the A/C system
  • Charge A/C system with up to 2lbs of R134 freon
  • Charge A/C system with flourescent dye for leak checking
  • Perform individual A/C component check for proper function and leak check of system.

$169.84 value. Expires 6/30/23. Must present coupon. 1234yf not included. Electrical check extra.


A/C Performance Check

  • Perform a baseline checkout of the A/C system
  • Charge A/C system with up to 1lb of newer R1234yf freon
  • Charge A/C system with flourescent dye for leak checking
  • Perform individual A/C component check for proper function and leak check of system.

Expires 6/30/23. Must present coupon. Electrical check extra.

How to Talk to Your Mechanic For Positive Results Every Time

Vehicle owners might not like to hear it, but they bear some responsibility if a maintenance procedure or a repair on their vehicle goes south. Often it comes down to one thing: You need to communicate clearly with your service advisor or the tech working on your car. Here are some things to say…

How You Can Help Your Technician

1. Describe a problem specifically – It’s better to say “I hear a high-pitched noise coming from the right rear wheel when I’m driving on the freeway” rather than “the wheel makes funny noises.”

2. Don’t diagnose the problenm – Today’s cars are more complex than ever. Automakers have established procedures to determine the cause of various problems, and it’s the tech’s job to sort it out.

3. Ask questions – Once a service advisor informs you what needs to be done, if there’s anything you don’t understand, ask about it before the work proceeds.

How Your Technician Can Help You

It’s not a one-way street. A repair shop has responsibilities to you, too.

1. Complete, clear answers to all your questions – If you’re working with a service advisor and aren’t getting the information you need, have them arrange for you to meet with the tech working on your car.

2. A written estimate of all the work that will be performed – This should include parts, labor, tax, and should occur before the work begins.

3. An explanation of what work is most important – If you’re on a budget and some repairs can wait, a tech or service advisor should be able to tell you.

Following these guidelines can go a long way toward taking the stress, misunderstanding, or conflict out of your relationship with those who service your vehicle.

Most Dangerous Cars of All Time

Pontiac Fiero

Although it featured a high safety rating, the Fiero would randomly erupt into flames, mainly caused by oil leakage and faulty wiring.

Audi 5000

The Audi 5000’s engine had a flaw that caused it to accelerate at any given moment, resulting in a lot of life-ending accidents.

Ford Pinto

1971-1978 – It’s downfall was due to a design flaw which put the fuel tank near the rear bumper. Due to the location, the tank would often blow up as a result of a simple fender bender.

Hey Len’s, Why Do I Have to Pay for a Diagnostic Fee?

Your check engine light came on the other day on your automobile.  Seems to be driving ok, but you call us to set up an appointment to have the problem diagnosed.   During your conversation with the service advisor, you are informed that there will be a diagnostic charge associated with this check out.  Why you ask?  You just want to know why the check engine light is on.  Let’s explain the difference in what you think you are calling for, and what we know we will have to do to diagnose it. 

Len’s can plug in a scan tool like the auto parts store and pull a code logged in the computer.  Let’s say it is a misfire code P0300 that is retrieved from the computers memory.  You think, a misfire code, I haven’t felt a misfire while driving.  This surely should be an easy thing to take care of.  The auto parts store will give you a list of possible causes like a spark plug or a fuel injector.  They may even recommend a repair.  This is not a diagnostic, it is a guess, and that is why they do not charge you to pull the code.  Len’s will not charge you to pull the code either.  However, that is where the similarities end between us and an auto parts store.

Off the top of my head, I can think of the following things that can set a misfire code:  a faulty oxygen sensor, a faulty mass air flow sensor, a failed fuel pump, a burned exhaust valve, blocked-up exhaust, bad gas, a slipped timing chain, shorted wiring, open wiring, or a worn camshaft.  That is 10 things I just listed that could be the cause of a random misfire.  NOTICE: no where in that list does it say spark plug, ignition coil, or fuel injector.  While these things can cause a misfire when faulty, the actual potential cause of the misfire is extensive. 

This is where the diagnostic charge comes in.  We will perform testing on all relevant components to isolate the actual cause of the misfire.  We start by identifying when the misfire happens, cold or hot, at idle or at cruise, under heavy load or light acceleration.  We then diagnose which cylinder in the vehicle is actually having a misfire.  Todays cars usually have either a 4, 6, or an 8 cylinder engine.  Once we have isolated the cylinder, we begin to zone in on the actual cause.  We may measure injector flow rates, primary and secondary ignition patterns, or perform a mechanical compression check on the cylinders.  The technician’s experience comes into play here.  They choose which tests to perform first, based on their experience diagnosing similar misfires on other vehicles. 

In some cases, you may also be asked to pay for a diagnostic for things like isolating a noise from a suspension component.  We charge this diagnostic when we are unable to isolate a noise by performing a visual inspection and a test drive.  In these cases, we actually hook up diagnostic equipment onto the vehicle around the suspected area of the noise.   We then test drive the vehicle listening through the diagnostic equipment to pinpoint which suspension component is making the noise.

In the end, performing the diagnostic in this way will lead to a logical positive testing result.  A logical positive testing result is what you are paying for when you authorize a diagnostic, you are not a paying for a guess. 

We authorize these diagnostics BEFORE we perform them, so you always have the option to opt out of the diagnostic if one is needed.

Drivability Diagnostics & Check Engine Light

Transmission Repair

Tires, Suspension, and Alignments

Factory Maintenance

State Safety & Emissions Inspection

Fluid & Filter Service

Berry Bread Pudding

Customer submitted receipe. Thanks Gabby!


3 slices Brioche cubed
3 tbsp granulated sugar
2 eggs
1/2 cup light cream or milk
1/2 tsp lemon extract
1/2 cup raspberries
1/3 cup blueberries
1 tsp powdered sugar
maple syrup

  1. Grease 6×6 dish with butter. Cut the brioche into small cubes (9-12 cubes per slice).
  2. In a large bowl, combine eggs, cream, sugar, and lemon extract. Whisk until well combined to make a custard. Set aside.
  3. Spread the brioche pieces in a single layer in banking pan. Spread handful of berries on the brioche.
  4. Add another layer of brioche and spread more berries on it.
  5. Pour the custard all over brioche.
  6. Press with spatula so that all the brioche is soaked in the custard. Keep aside for 10 minutes to let custard soak in.

AIR FYER: Cook for 15-20 minutes at 330F, or until custard is set in the middle.

OVEN: Bake for 40-50 minutes at 350F, or until custard is set.

Serving: Sift some powdered sugar on the top. Serve warm or cold with a drizzle of maple syrup or your favorite ice cream.