Is your car is ready for the Summer? – Updated

It has taken longer than last year, but the warm weather is finally here.  The summers in this area can get hot and it is a good idea to make sure your car is ready for the hot weather.   A great way to save money is to do these yourself, if you don’t already. If you are not comfortable doing any of these yourself, take your vehicle to your mechanic and read our post on how to save money on car repairs.

To prepare my vehicle for warmer weather I always do the following:

  • Adjust Tire Pressure
  • Change Engine Oil
  • Replace Air and Cabin Air Filters
  • Check Fluids and change if necessary
  • Evaluate the Cooling System
  • Inspect the A/C System

Tire Pressure:

The first thing I always do whenever the weather changes is check the tire pressure. Often a change in temperature causes a change in tire pressure.  Ideally, you should check your tire pressure more often, but at least every season. Most newer vehicles have tire pressure monitoring systems (TPMS); however, depending on the vehicle make and model, their accuracy can vary. Some are great, some are not so great.

It’s best to take the time to check the pressure yourself.  Look on the inside of the driver’s door, and there should be a label with the correct tire pressure for your vehicle.  Your owners manual will also have this information.

Check the Pressure:

Now that you know what pressure your tires should have, measure the actual pressure using a tire pressure gauge. I always keep one in my glove box.  You can purchase them at any auto parts store, Walmart, Target, etc.  If your tires are over inflated, use the gauge to let out air, until the pressure is correct. Some gauges have a small button you press to let air out; others you can turn over, and use the back to let air out.

If your tires are under inflated, use an air compressor to add air. I keep a small 12 volt air compressor in my trunk for inflating tires. If you don’t have one, many gas stations have tire inflation stations; although most of them charge about $1 to use.

Notes on Tire Pressure:

According to under inflated tires can lower gas mileage by 0.2% for every 1 psi drop below normal.  Additionally, improper tire pressure can lead to all sorts of problems including excessive tire wear, steering problems, and front end component wear. Performing this seemingly insignificant task at least seasonally can save you a lot, in the long run.  Once you get the tires to the correct pressure, you may need to re-calibrate your tire press monitoring system if your vehicle has one.  Check your owners manual for how to do this.


Air and Cabin Filters:

All cars have an air filter(s), and some cars have a cabin air filter(s).  Check your owners manual for the interval for changing your air filter (and cabin filter if your vehicle has one.  If you haven’t changed it in a while now is a good time to do so.  You can buy an air filter from any auto parts store.  On most vehicles they are very easy to change yourself.  YouTube is a great resource for how to videos on just about everything; most likely if you search there is a video showing how to change your air filter.

Cabin Air Filter:

Cabin air filters are more common in later model vehicles and filter the air coming in through the vehicles air vents.  They remove dust, pollen, and dirt from the air to ensure the air being pumped into the car is clean.  These filters can obviously get dirty and sometimes they can get wet.  Making sure you have a clean dry cabin air filter is a must before you start running the ac frequently.  Changing the cabin filter is a bit more difficult than the air filter.  If your vehicle has one, check YouTube and if it looks too difficult have your mechanic change it.



Proper fluid levels are essential for the operation of every vehicle system. Check all your fluids and make sure they are at the proper level and are clean without any debris.  Read the owners manual to find out how to check each fluid, and how often they need to be changed.

Oil Level:

All cars consume oil.  An engine in good shape will consume less, a more worn engine will consume more.  Using the dipstick check the oil level and make sure it is in the range.  If the level is low, add oil slowly and check the level again.  Keep adding slowly until the level is in the middle of the range.  Do not overfill oil.  Too much oil can cause the crankshaft to whip the oil into foam and starve the engine of oil as air from the foam builds up in the oil pump.

Oil Changes:

Regular oil changes are a must if you want to avoid costly engine repairs.  The old rule of thumb was every 3,000 miles or 3 months.  Today, most cars have higher oil capacity, oil quality is better, and engine manufacturing techniques have improved.  The result is the number of miles between changes has increased, in some cases significantly.  Check your owners manual to find your internal.  The interval usually ranges from 5,000 to 15,000 miles.

I recommend changing oil at least twice a year even if you haven’t reached the interval.  If you haven’t changed your oil in a while, now may be a good time to do so.

Notes on Oil:

A car engine has a large number of moving parts and metal on metal contacts (bearings, piston rings, etc.).  Engine oil keeps these parts lubricated so that they do not wear down quickly.  I highly recommend using a high quality synthetic oil.  The price differential between regular oil and synthetic oil is not nearly as wide as it used to be.  Synthetic oil can extend engine life and help prevent costly repairs.  There is a reason that high end manufacturers like Mercedes use synthetic oil.  There is a brief summary of the benefits of synthetic oil on how stuff works.

Auto Transmission Fluid:

An automatic transmission needs fluid for both compression and lubrication.  Low, or dirty fluid will cause the transmission to fail sooner.  Check the transmission fluid level and quality.  With the engine running and in park, remove the dipstick and check the fluid level and quality.  It should be red, and should have a consistency slightly lighter than oil.  The fluid should not be dark and should not smell burnt.  Have it changed if this is the case.  The fluid level should be within the range noted on the dipstick.  If it is low, slowly add fluid the same way you add oil.

A note on Transmission Fluid:

Many newer vehicle have sealed transmissions which do not require you to check or even change the fluid.  Check your owners manual to see if your vehicle is one of these.

A note on brake Fluid:

Brake fluid is located in a reservoir under the hood on the driver’s side firewall.  Most reservoirs are translucent to allow you too see the level just by looking.  Brake fluid is essential to the operation of your brakes.  There should not be any leaks and you should not have to add fluid if your braking system is in good shape.  The only time it may be necessary to add brake fluid is if you recently change your brake pads or had other brake work done and the lines were not properly bled. If you are adding brake fluid regularly have the vehicle looked at.


Cooling System:

The cooling system is essential to the operation of your engine and having an efficient cooling system is a must for the summer.  Overheating can lead to expensive repairs.  An inefficient cooling system also affects how well your A/C will work.   Again, if you are not comfortable doing this, take your vehicle to your mechanic.

Cooling Level and Quality:

Make sure the vehicle is cool and has not been driven recently.  First, open the hood and make sure there are no leaves or other debris in any area.  Open the radiator cap and check the quality of the coolant the coolant mixture. If you have a coolant tester they are very easy to use, simply draw the liquid into the tester and observe the reading. Without the tester, at least perform a visual inspection. Remove the caps to the reservoir and the radiator and look at the color of the coolant. Depending on what year and model vehicle you have, your coolant may be green, red, orange or blue. Check your owners manual to see what type of coolant your vehicle uses.

You will want to look at both the color and the consistency. It should be liquid, similar to water, without solid particles. Look in the reservoir and at the bottom of the radiator cap.  They should both be clean; if there is any sludge you will want to have the system flushed. If the coolant is ok but the level is low, add a 50/50 mixture of antifreeze and water to the reservoir.  It is not uncommon to have to add coolant from time to time.  If you have to add a significant amount of coolant often, you likely have a leak or other problem and should take the vehicle to a mechanic.

Notes on Coolant Level:

When operating correctly the coolant reservoir will empty into the radiator and fill back up from the radiator as the level in the cooling system changes.  Occasionally the reservoir can become disconnected from doing this caused by a faulty radiator cap, clogged hose, or other problem.  If this is the case, your coolant may be low, but the level in the reservoir will look fine. This can lead to overheating.  In the next section we’ll go over how you can make sure your reservoir is working properly.

Cooling System Leaks:

Start the vehicle and let it warm up. Put the heat on high, and let the vehicle run, while you visually inspect the hoses, radiator, reservoir, and water pump. Do not get too close to hot or moving parts. Be careful while doing this! There are two large hoses connected to the radiator; check the connections for any leaks. There are also the smaller hoses running into the firewall, check these for leaks as well. Once the car has been running with the heat on, and it is at normal operating temperature, look for any drips on the pavement. Make sure the AC is off when you do this; having the A/C on will cause condensation (water) to drip. This is not a leak but normal when the A/C is on.

If there is a drip with the heat on (A/C off) move the car and take a look at the liquid.  Check the color, if it is the same color as your antifreeze then you likely have a coolant leak and should see a mechanic before it gets worse. If there are no drips check to make sure the temperature is staying at operating temperature and your cooling fan is operating.  The fan should come on when your engine reaches normal operating temperature.  While the vehicle is still running, turn the heat off and watch for the fan to come on.  If the fan does not come on, your vehicle will overheat.

Checking the Reservoir:

Now that the vehicle is running, the engine is at operating temperature, and the fan has come on, check the reservoir.  Do NOT open it.  Simply feel the reservoir to see if it is warm or cold.  If it is cold, wait a few more minutes with the vehicle running and heat off.  It will get warm if it is operating correctly.


A/C System:

Having a working A/C system in the summer is important to most people. Your A/C system is made up of three major components; the compressor, the condenser, and the evaporator.  The system is charge with refrigerant, and the components work together to remove heat from the air in your vehicle.

Inspect the A/C system:

Now that you have the engine running at operating temperature and there are no coolant leaks, turn the A/C on high.  The compressor should come on (you will hear it and the idle may change slightly).  Within a few minutes the air coming out of your vents should be cold.  If the air gets cooler but is not as cold as last year; you can recharge the system yourself.  If the air stays warm, your system likely has a leak and you should have it looked at before putting refrigerant in.

Notes on A/C:

In addition to the three main components your A/C system also has a number of hoses and lines.  These are where many refrigerant leaks occur.  The refrigerant in your system contains an oil, which lubricates rubber seals and o-rings at many of the line connections.  During the winter, when you don’t use the A/C, these rubber seals and o-rings can dry out and crack.  This causes them to leak.  It is a good idea to run the A/C at least once a month, even in the winter, to prevent these seals from drying out.