Monthly Archives: April 2014

Timing Belt

Ever heard the sad tale of a staggeringly costly repair bill from a broken timing belt? Bad news. Let’s St. Peter car owners take a lesson from their woes and remember to think about our vital timing belt.

First, let’s review what a timing belt does. The top part of the engine, over the cylinders is called the cylinder head. The head contains the valves. There’s at least one valve that lets the fresh air into the cylinder. This air, mixed with fuel, burns to create power. Then another valve or two open to allow the exhaust out of the engine. Each cylinder has 2 to 4 valves – that’s 12 to 24 valves for a V-6, up to 32 values on a V-8. The opening and closing of the valves is done by a camshaft. The timing belt uses the rotation of the engine to drive the camshaft which opens and close the valves. It’s called a timing belt because it has to be adjusted to rotate the camshaft to keep proper time with the engine so that everything’s in sync.

The timing belt is a toothed rubber belt . But some cars use a timing chain or timing gears instead of a belt. Timing chains and gears are much more durable, but auto manufacturers are using belts more because they are quieter – and cheaper. If you have a small or mid-sized passenger car, crossover or mini-van, chances are you have a timing belt.

Unfortunately, timing belts fail without any warning. That shuts St. Peter drivers down right away. Your Autotronics of ST Peter service professional can inspect your timing belt and look for cracks and looseness. But getting to the belt to take a look can be almost as much work as changing it on some cars. That’s why car makers recommend replacing the belt from time to time. For most vehicles it’s from 60,000 to 90,000 miles or 95,000 to a 145,000 kilometers. If your owners’ manual doesn’t specify an interval ask your knowledgeable Autotronics of ST Peter tech.

One AutoNetTV producer has had two timing belts fail. The first was while he was waiting at a stop light – that costly repair cost several thousand dollars. The second was while driving on the highway – that one cost more than twice as much. Both had the cars out in the shop for three weeks. His cars had what we call “interference engines”, meaning that the valves and pistons are very close to each other. If the timing belt slips even one notch, the pistons will slam into the open valves. That’s why our friend’s highway failure was so much more expensive – his engine was traveling so fast that the valves were smashed and they chewed up the cylinder head.

A non-interference engine will just shut down if the timing belt breaks. You’re stranded, but the engine doesn’t suffer permanent damage. In both cases, our hapless friend was just a couple oil changes past the recommended interval for changing the timing belt. This is one of those things that St. Peter car owners just cannot put off. Now replacing a timing belt is not cheap – but repairs for a broken belt can be far more costly.

The team at Autotronics of ST Peter recommends St. Peter motorists check their owners’ manual ASAP – especially if you have more than a 60,000 miles or 95,000 kilometers. You may need to get that belt replaced right away. And on many cars, the timing belt drives the water pump. So, it may be a good idea to replace the water pump while you’re at it because 90% of the work required for the new pump is already done with the belt change. Doing both at the same time saves you a lot of money because as they say, “timing’s everything”.

Timing Belt

Ever heard the sad tale of a staggeringly steep repair bill from a broken timing belt? Bad news. Let’s take a lesson from their woes and remember to think about our timing belt.

First, let’s review what a timing belt does. The top part of the engine over the cylinders is called the cylinder head. The head contains the valves. There’s at least one valve that lets the fresh air into the cylinder. This air, mixed with fuel, burns to create power. Then another valve or two will open to allow the exhaust out of the engine. Each cylinder has 2 to 4 valves – that’s 12 to 24 valves for a V-6, up to 32 values on a V-8. The opening and closing of the valves is done by a camshaft. The timing belt uses the rotation of the engine to drive the camshaft which opens and close the valves. It’s called a timing belt because it has to be adjusted to rotate the camshaft to keep proper time with the engine so that everything’s in sync.

The timing belt is a toothed rubber belt. But some vehicles use a timing chain or timing gears instead of a belt. Timing chains and gears are much more durable, but vehicle manufactures are using belts more because they are quieter – and cheaper. If you have a small or mid-sized passenger car, crossover or mini-van, chances are you have a timing belt.

Unfortunately, timing belts fail without any warning. That shuts your engine down right away. Your pros at Autotronics of St. Peter can inspect your timing belt and look for cracks and looseness. But getting to the belt to take a look can be almost as much work as changing it on some vehicles. That’s why manufacturers recommend replacing the belt from time to time. For most vehicles it’s from 60,000 to 90,000 miles or 95,000 to 145,000 kilometers. If your owner’s manual doesn’t specify an interval, ask your service advisor at Autotronics of St. Peter.

Someone we know, who shall remain anonymous, has had two timing belts fail. The first was while he was waiting at a stop light – that repair cost several thousand dollars. The second was while driving on the highway – that one cost more than twice as much. Both had the cars out in the shop for three weeks. His cars had what we call “interference engines,” meaning that the valves and pistons are very close to each other. If the timing belt slips even one notch, the pistons will slam into the open valves. That’s why our friend’s highway failure was so much more – his engine was traveling so fast that the valves were smashed and they chewed up the cylinder head.

A non-interference engine will just shut down if the timing belt breaks. You’re stranded, but the engine doesn’t suffer permanent damage. In both cases, our hapless friend was just a couple oil changes past the recommended interval for changing the timing belt. This is one of those things that St. Peter drivers just cannot put off. Now replacing a timing belt is not cheap – but repairs for a broken belt can be far more expensive.

The team at Autotronics of St. Peter recommends St. Peter drivers check their owners’ manual ASAP – especially if you have more than a 60,000 miles or 95,000 kilometers. You may need to get that belt replaced right away. And on many cars, the timing belt drives the water pump. So, it may be a good idea to replace the water pump while you’re at it because 90% of the work required for the new pump is already done with the belt change. Doing both at the same time saves you a lot of money because as they say, “timing’s everything.”

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com

 

Direct Fuel Injection Update From Autotronics of ST Peter

For those of you in St. Peter MN who pay attention to these things, you may have been hearing about the new direct injection engines and want to learn more about them. Some deliver the power of a V8 with the economy of a V6.

For example, in one family of engines the conventional V6 makes about 250 horsepower. The direct injection version of the same engine makes over 300 horsepower and gets essentially the same gas mileage. The turbocharged version makes over 350 horsepower.

So what are the differences from a conventional engine?

The core difference is in the fuel injection system. The system most vehicles use now is called a port injection system. The fuel injector squirts fuel into a port just outside the cylinder where it’s then drawn into the engine with the air.

With a direct injection system, the injector squirts the fuel directly into the cylinder. The gain in power and economy come because fuel injected directly into the cylinder during the combustion cycle is burned much more efficiently.

First, the fuel is squirted in at hundreds of times more pressure, so it’s atomized much better and burns cleaner and stronger. The other big advance is in electronics. Faster engine management computers can control the additional precision required to manage direct fuel injection.

Fuel injectors are precision instruments. They have to deliver a precise amount of fuel at exactly the right time. The design of the engine also dictates a particular spray pattern for the fuel. If a fuel injector is dirty or gummed up, it can’t do its job as well. That means less power and worse fuel economy for your minivan and can lead to damaged fuel injectors.

Replacing fuel injectors isn’t cheap. Direct injection injectors are even more expensive because of the extremely high-pressure they use. Same thing for diesel fuel injectors; we’re talking mortgage payment-range to replace a set of diesel injectors.

A professional fuel system cleaning from Autotronics of ST Peter gets out the gum and varnish in the whole system, including the fuel injectors. Keep those injectors clean and they’ll last a long, long time.