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A word about timing belts & chains

     Below I explain the function and importance of your vehicles timing belt or chain and explain what can happen if its replacement is ignored. Its replacement alone can save you thousands of dollars.

     We all do the best we can to protect our vehicles and we all make sure to keep them maintained against all possible threats and dangers. However, it should not be surprising to learn that one of the greatest dangers to high mileage cars is also one of the least well known. While we expect and try to prevent cases of engine or transmission failure, the death of many older or high mileage cars is nothing other than a failure of the timing belt. However, to understand what makes the timing belt so important and how we can prevent it from failing; we first need to learn a little bit about what it does and what we should expect from specific car models when it comes to life expectancy of the belt.

     The timing belt serves a very important part when it comes to making your engine run. Namely, the timing belt is the belt that controls the camshafts in your engine and keeps the entire operation running smoothly. Note that timing belts are present in engines with overhead cams and are essential to keep these cams turning at the right time in order to keep the engine running. Remember that a camshaft is the shaft that opens and closes the intake and exhaust valves in your engine, both letting air & fuel in to create combustion, and venting the exhaust that comes from those explosions. A timing belt must be properly calibrated in order to move in time with the motion of the pistons. Some engines with timing belts also operate the water pump.

     When it comes to engines, the two most important terms to remember when talking about timing belts are "interference" engines and "non-interference" engines. Interference engines have a very, very small amount of space between the valves and pistons, while non-interference engines tend to have a lot more room.

     These two types of engines make a major difference when figuring out how bad a timing belt failure can be for your engine. In an interference engine, with little space between the valves and pistons, a slip or break in the belt can send a piston flying into an open valve. When this happens, it is like an engine self-destructing, which at times is cost efficient to repair or will become nothing more than an unusable mess of metal due to the extent of the damage. This is not to say, however, that a timing belt failure in a non-interference engine will not be damaging, as it can still cause a great deal of damage to many engine components. However, a timing belt failure in a non-interference engine will not cripple the motor.

     Regardless of what type of motor is present in your vehicle, a failure in the timing belt will cause the engine to suddenly stop. This means that your car will suddenly stop running and you will not be able to get it started again. In all cases, this means calling a tow truck to come pick up your now non-running vehicle.

     If all of this sounds like a nightmare, that's because it can really turn out to be one. Luckily though, timing belt failure is somewhat easy to prevent, and although it may not be the cheapest or easiest operation in the world, it is definitely a better option than purchasing either a new car or a new engine.

Of course, checking to see when your timing belt was last changed is not always the easiest task either. If you have ever had it replaced in the past, you should have the mileage written down as to when it was changed. Now if you have purchased your vehicle used, there may be a sticker located under the hood that gives the mileage of the last change. If you cannot find this sticker, then it may be better to have the belt changed just to be on the safe side. If you have the owner's manual for your vehicle, look in it, for it should state in the maintenance section when the belt should be changed.

     If you have trouble finding out when exactly the belt should be changed; you could consult either a local mechanic, a dealership or us for the exact mileage number. A good general rule of thumb is that a timing belt should be changed every 60,000 to 75,000 miles, although some belts are designed to last up to 100,000 miles before requiring a change. Regardless though, it is best not to let a belt go more than 80,000 miles or so, even if the recommended change point is a lot higher. Changing your belt early is definitely a lot safer for your engine, and a little money out of pocket can save you a lot of money and a new car in the long run.

     Remember, even though you may get your oil changed every 3,000 miles, and do all of your scheduled repair services, nothing can save you from a timing belt failure. Make sure to get your timing belt replaced regularly and by a certified mechanic. It can mean the difference between a good running car and useless piece of metal.

     With all that said, over the past year I have replaced or rebuilt more engines than replacing the timing belt or chain. Vehicle manufactures do not have a timing chain replacement schedule. Most timing chain tensioner and VT cams are operated under oil pressure, and the lack of oil pressure can cause noise and damage within the engine. Also, the guides on timing chain driven engines are made of a plastic like material and do wear of the life of the engine. This wear will later lead to less tension on the chain and possible guide breakage. My opinion of timing chain replacement schedule for all chain driven timing engines would be from 150K to 175K miles on the vehicle. If your vehicle has had proper oil changes then I would go as high as 200K miles but not over that. So, contact any mechanic or myself to get it replaced before it goes out, for it will save you money, time, frustration, and a headache.

     Call Scott or Russell @ 225-44-FIXED, 225-443-4933, or 225-400-4140

     Just had to add this. I have replaced many 4.6L & 5.4L (2 and 3 valve) Ford motors due to failed timing guides and only replaced the timing sets on a few when there was timing chain slap which was caught before engine failure. Ford does not have a scheduled mileage for replacement of the timing set in the 4.0L, 4.6L, or the 5.4L motors. My recommendation is to change it between 150K & 175K miles. Most of my engine replacements had severe engine damage around 200K miles when the guides failed. Then the motor should last another 200K miles after replacing the timing set. I've said that because I have been swamped with the 4.6L or 5.4L engine replacements or timing set replacements recently. As it stands, most if not all engine manufactures do not have a set period or mileage for changing timing chain set on timing chain operated engines. I recommend 150K-175K and if you have had excellent oil changes 180K-230K

     My name is Scott and our business name is Xtreme Auto Repair. We can be reached at 225-44-FIXED, 225-443-4933. Interest free financing is available for those people in need.

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