AUTONET TV

The Truth about Tire Pressure (Tire Inflation)

Most light vehicles (under 10,000 pounds/4,500 kg) in North America sold from 2008 model year on have a feature that many people are confused about.  It's the tire pressure monitoring system (TPMS).  You may have some experience with it yourself if you own a newer vehicle.  Vehicles with TPMS have sensors in each tire that are supposed to warn the driver when tire pressure gets dangerously low.  That's important because tires that are significantly under-inflated can cause very serious accidents.

Unfortunately, many drivers think the TPMS does all the work keeping track of tire pressure. To them, as long as the warning light or gauge isn’t giving a warning, the tires must have the proper amount of air pressure in them.  That's not the case.

Tire pressure monitoring systems aren't all created equal.   Some give you a digital readout of the pressures in each individual tire.  But many simply have a warning light that looks like the cross section of a tire with an exclamation point in the middle.  If you don't know what it is, it's because it's not instantly recognizable as a tire.  In fact, one company that makes TPMS, Schrader Performance Sensors, surveyed drivers.  Their study showed that more than 40 percent of drivers didn't know that that warning light was. 

One out of 5 of the drivers who did know what the light was only looked at their tires after the light came on to see if they could see any that needed air; they never checked them with a tire gauge or had someone else do it.  Ten percent of them didn't do anything when the light came on.

In most vehicles with TPMS, the warning comes on only when the tires are more than 25% underinflated.  The American Automobile Association says that's under the pressure you need for safe vehicle operation.

The bottom line is once a month you should make sure your tires are inflated to the manufacturer's recommendations.  That means each tire should be measured with an accurate, external tire gauge.  To be confident you are getting a correct reading, take your vehicle to a reputable service facility where their equipment is calibrated and they know what they're doing.

Severely underinflated tires can contribute to an accident that kills or severely injures people.  The idea behind TPMS is well intended, but the system was never meant to replace regular inflation measurements and maintenance.  Periodically have your tires checked for proper inflation.

A.G. Automotive & Diagnosis
19735 Sherman Way Suite 2
Winnetka, CA 91306
(818) 438-9608
http://www.agautodiagnosis.com

Your Vehicle's Hissy Fit (AC System)

When you hear hissing sounds coming from your vehicle, you might start thinking the worst.   One type of hissing coming from around your air conditioner may be a normal sound, or it could be a sign of serious trouble.

First - the normal sound.  When you turn off your vehicle, the refrigerant goes from its high-pressure side to the low-pressure side. Some of those noises are normal.  But when it hisses all the time, that's another story.

One cause could be that the refrigerant is leaking.  Air conditioners are fairly complex systems that involve various pumps, hoses, valves and motors.  When your air conditioner is cooling, the refrigerant changes from a gas to a liquid and back.  That refrigerant is under pressure, and there are many places it can leak from. 

A hissing sound can also be a failed valve in your air conditioner's compressor.  It is what controls the refrigerant's pressurization.  It's important to have this fixed fairly quickly after it develops a problem because when it isn't, that can lead to more extensive—and expensive—repairs.

If you hear screeching coming from your air conditioner at the same time you hear hissing, your compressor may be on its last legs. It could also be a defective clutch. 

Any time you hear a noise you haven't routinely heard before, bring your vehicle to us so a technician can check the various components and properly repair the problems.  Air conditioning systems are complex and are best handled by a professional with the right tools and equipment.  When your AC has a hissy fit, let us cool it off and you at the same time.  

A.G. Automotive & Diagnosis
19735 Sherman Way Suite 2
Winnetka, CA 91306
(818) 438-9608
http://www.agautodiagnosis.com

Taking the Heat (Batteries in Hot Weather)

Quick question.  Which is tougher on a vehicle's battery, the heat or the cold? Believe it or not, it's the heat.  Think about it.  The battery often sits in the engine compartment next to that motor generating lots of heat.  That can accelerate corrosion in the battery and may even cause water in it to evaporate.  That will weaken the cranking power of your battery and shorten its life span.

To take care of your battery, here are a few suggestions.  It's a good idea to have it checked out to see what shape it's in.  At your vehicle service facility, they have diagnostic equipment that can evaluate its condition.  That can help you know how long you can expect it to last before having to replace it.  At the same time, you should have your charging system evaluated.  If your battery is not getting charged properly, it can be in great shape but not very useful when it comes to starting your vehicle.  A technician will also check the cable connections that should be free of corrosion and tight.

Keep in mind that under certain conditions, a vehicle battery can cause an explosion if close to an electrical spark.  This is why the safe way to go is to have a qualified, trained technician do the work. 

Your battery is important both in hot and cold weather.  When it comes to starting your vehicle, make sure it's always up to the job.

A.G. Automotive & Diagnosis
19735 Sherman Way Suite 2
Winnetka, CA 91306
(818) 438-9608
http://www.agautodiagnosis.com

Cool Running (Water Pump)

Your vehicle is like you in a way.  When it gets hot, it needs to be cooled down.  And one of the key parts to keeping it cool is the water pump.

Now, that's a bit of a misnomer.  It IS a pump, but it's pumping coolant, not pure water.  Cooling off your engine is vital since it builds up heat when it creates power by burning fuel.  Your water pump acts as a way to recirculate that coolant.  It goes through a series of tubes and hoses through the engine where it picks up heat, then is sent off to the radiator to get rid of that heat.  Cooled off, the coolant is recycled through the water pump to start the journey again.

The water pump works by taking mechanical power from the engine, usually from a belt.  Obviously, that belt has to be in good condition and adjusted properly or else the water pump won't be able to do its job.

Here are some things to look for that will signal problems with your water pump.  If your heat gauge is erratic or showing a much higher than normal temperature, that could be a sign of trouble.  Another is if you hear a whine under the hood.  And if that gets louder when you go faster, get it checked right away.  You may see steam coming out from under the hood or coolant may be leaking. 

These signs signal that it's time for you to have a technician check to see where the problem is. Some water pumps are powered by a timing belt.  If your vehicle has that design and your timing belt is due for replacement, sometimes it's a good idea to replace the water pump too, even if it's working properly.  That's because the labor to replace the timing belt can be expensive and it may be wise to proactively take care of the water pump while it's disassembled.

Your service advisor will explain the options available and offer the best path to keeping your water pump doing its job.  Your engine's life depends on it.

A.G. Automotive & Diagnosis
19735 Sherman Way Suite 2
Winnetka, CA 91306
(818) 438-9608
http://www.agautodiagnosis.com