Most cars on the road today are electronically controlled and have very advanced computer systems built into them that most people don’t understand , let alone try to repair . But if you follow these simply repair tips, you can avoid having to go through the fun of taking your vehicle to a shop and being hit with a hefty repair bill.

1. Engine Oil. I know that it sounds simple but I have seen a lot of engines go to the junk yard only because the owner neglected to either changer the oil or didnt realize the oil level was too low and caused the engine to burn up. Remember the rule of thumb is 3 months or 3,000 miles no matter what. Get in the habit of checking it once a week . This way you will notice if you are loosing oil that you didnt know about. If possible change your own oil . You will discover a problem leak before your mechanic does.

2. Spark Plugs. Changing your own plugs out not only increases your engine performance but the plugs will tell you everything that is going on inside the cylinders , if you know how to read them. Here are a few guide lines when checking your plugs;

A. A normal spark plug should have a light tan or gray deposit on the firing tip.

B. An oil fouled plug indicates an engine with worn piston rings and or bad valve seals allowing  oil  to enter the combustion chamber. You may have  bluish white smoke coming out of your tail pipe if you have these spark plugs. It also causes hard starting, misfiring and hesitation. The only way to fix this problem is with an engine overhaul .

C. A worn plug is normal if the plug hasn’t been changed for quite a long time. The gap will be excessive and it will have a rounded electrode with small deposits on the firing end. It causes hard starting in damp or cold weather and can cause bad fuel economy.

D. Carbon deposits on a plug indicate a rich fuel mixture or weak ignition. Check your plug wires, distribitor cap and rotor for signs of wear. It causes misfiring, hard starting and hesitation.

E. A plug that has pieces of the ceramic insulator missing or chipped or cracked could be caused by detonation which could result in piston damage. Avoid  ” Lugging ” the vehicle and make sure the gap is set right. Also check the knock sensor is working properly.

F.  If you pull a plug and the tip is crushed against the electrode then you may have a foreign object in the combustion chamber or you may have a plug that is to long for that vehicle. If this is the case, you may have suffered piston damage and you will experience a dead cylinder which means if you have a four cylinder engine then it will only run on three cylinders, rusulting in a lack of power and poor engine performance.

3.  Spark plug wires. As a rule of thumb, you should change out your wires every 60,000 miles. But check them for signs of damage, burns, cuts or breaks in the insulation. If you are going to test them with an Ohm meter then the resistance should not be greater then 25 kilo ohms. When changing wires, its best to do them one at a time so as not to mix up the firing order which can be very fun to figure out on some vehicles.

4.  Distibutor cap and rotor. This is if your vehicle is equipped with a distributor. As vehicles advance with more on board electronics, the need for some mechanical components is no longer a requirement. If you pop the hood and can’t find a distributor chances are you don’t have one. This is referred to as a DIS system or Distributorless Ignition System. Look on the inside of the cap and check for signs of a white deposit build up or burning at the tip of the rotor. If so then replace them as a set.

5.   PCV valve. That stands for Positive Crankcase Ventilation valve. The easiest way to check it is to shake it. If it rattles then your ok, but if you hear nothing then replace it . When they go bad you could experience a possible intake vacuum leak which would cause erratic engine conditions or the inability of the crankcase to adequatley vent combustion blow-by gasses causing potential oil leaks.

6.  Air Filter. Most tune ups include changing the air filter out. If it becomes clogged with dirt or other material then your engine wont be able to breath. Imagine trying to run a few miles with a plastic bag over your mouth . Its the same thing. Some vehicles are built with a guage to let you know when its time to change  the air filter but a good rule of thumb is to check them with every oil change .

7.  Fuel Filter. Here is  one that most people either forget or dont want to mess with. I would recommend that if you have never done one then leave it to someone who has. They can require special tools and you will have to know how to relieve the fuel pressure before trying to remove them. If they become clogged, the engine may feel as if its running out of gas or has a lack of power upon acceleration.

8.  Oxygen Sensor. People often misunderstand how the O2 sensor works and which ones if any should be changed out during a tune up. For starters, there are two kinds of O2 sensors. Heated and non heated. You can tell by how many wires are coming out of them . One wire, non heated. Two to Four wires,  heated . The most expensive is the Heated O2 sensor and some vehicles have up to four of them. They make special sockets to remove them and the only way to test them is with either an Ohm meter or a scan tool. They are categorized as upstream and downstream and only the upstream sensors influence the engines fuel management system and can create a Lean or Rich condition. The downstream sensors monitor the catalytic converter and will send a check engine light of there is a issue. Change out the upstream sensors during a tune up.

9.  Belts and Hoses. Most vehicles on the road today use a single belt or serpentine belt while others like Honda use a Multi Ribbed and V-belt configuration to  operate all the accessories ( ie. power steering , alternator , A/C, smog pump ect ) The serpentine belt cannot be adjusted due to an automatic tensioner while the other two belts can be and should be based on belt deflection . Belts that are loose will have a squealing sound upon start up or on acceleration. On all three belts check for signs of damage or wear like glazing, cracking, fraying ,crumbling or missing chunks.

As far as hoses are concerned. Upper, lower radiator hoses and heater hoses should be checked for bulging,damage,leaks and loose clamps during every oil change. Always check  them when the engine is cold .

10.  Fluids. Every time you pop the hood, make it a habit to check all the vital fluids. Engine oil, power steering fluid, over flow tank for the radiator, windshield washer fluid and of course the transmission fluid. To check it the engine must be running so be careful when putting your hands close to moving parts. The fluid should be a healthy pink or red color and should be up to level with the engine warm. Smell the fluid. Does it look brown and smell burnt. Then chances are you need a transmission flush.

If you are not familiar with changing your transmission fluid then I recommend taking it to someone who is. It can be very time consuming if you dont know what you are doing and not to mention a mess. But if you dont have it done every 30,000 miles you may experience hard shifting , delayed shifting or even acceleration slippage.

Well I hope that helps you with tuning up your own vehicle and remember to consult your owners manual or an aftermarket repair manual for more details .If you have any comments on this or have a general question about automotive repair, then I would like to hear from you . Until next time, this is Jeff Williams saying thanks for stopping by.