Detailed Topics

When Should I Replace MyTiming Belt?

Many people are confused by a timing belt. Not every engine has one, but those that do require replacement at a specific mileage or time interval. Timing belts offer a number of advantages, such as light weight and precise timing over their lives. The timing belt is also far less affected by lubrication problems than a chain or gear drive. Like any piece of rubber, a timing belt will deteriorate in time. To know if your engine has a timing belt, it is best to refer to the owner's manual or ask to a trusted professional.

How timing belts work

 

They design a timing belt with teeth that mesh with grooves in the crankshaft and camshaft sprockets. This arrangement allows the timing belt to keep the camshaft and crankshaft in perfect time. Engineers normally provide a tensioner which keeps the timing belt tight.

Timing belts are made of a very durable rubber, with layers of cord to prevent stretching. This arrangement provides years of trouble free service and precise valve timing.  Eventually the rubber and cords begin to deteriorate.  They recommend replacing the timing belt for this reason.  The recommended replacement interval for a timing belt varies, depending on several factors. The design of the engine and the age of the belt determines when it should be replaced, and vehicle manufacturers provide guidelines which must be followed.

Interference and non-interference engines

We often hear engines referred to as interference and non-interference types. An interference engine is one where the engine valves, and pistons occupy the same place, just not at the same time. On an interference engine, the valves will hit the pistons, if the timing belt breaks or slips. The result will be engine damage.

They use interference designs because they allow more horsepower. The drawback is an elevated risk of the belt breaking or slipping. Pushing such an engine beyond the recommended time or age interval is very unwise.

For a list of popular Asian and Domestic interference engines, please click here.

When they build an engine for lower performance, the valves do not extend as far into the cylinders. They call these engines non-interference type. This is a bit misleading as under the wrong conditions, any engine may suffer damage if the valve timing is off. The name, non-interference sometimes lulls people into a false sense of security.

When timing belts slip or break, at least the engine will stop running and other damage can occur. An engine listed as non-interference does NOT mean it is safe to neglect timing belt replacement. Timing belts are normally recommended between 60,000 and 105,000 miles. The interference type engines are closer to the lower end and the non-interference type closer to the higher end.

The age factor 

Time is perhaps more important than miles, in the life of a timing belt. Seven years is the maximum life of the timing belt, recommended by most manufacturers.

For instance, even if the engine has only 30,000 miles, but is seven years of age, the belt should be replaced. The timing belt in the photo above is eight years old, and only has 30,000 miles of use. Because timing belts deteriorate with age, time is even more critical than miles. More timing belts break due to age than mileage.

Things replaced with the timing belt 

Replacing a timing belt normally involves a good deal of effort.  Because of this, there are several other components in near proximity, that might also be replaced. For instance, the water pump, if under the timing cover, can be replaced at a greatly reduced price. Because water pumps wear out, many people see the wisdom of replacing it when the belt is replaced.  Not replacing these components often results in an expensive re-do of the timing belt job.  Doing a complete job is far less expensive and less dangerous than having to do the job over.

Other components often recommended include:

• Idler pulley(s)
• Timing belt tensioner(s)
• Accessory belt(s)
• Cam shaft seal(s)
• Front crankshaft seal
• Oil pump seal (if present)
• Balance shaft belt (if present)
• Balance shaft seal (if present)

Some engines may have other components and wear items.  Spark plugs, PCV valves, air and fuel filters may also be replaced if needed.

Beware the belt-slap

When pricing a timing belt replacement, we must know what we are buying. Some companies quote a price for replacing the belt alone. Quality auto repair shops refer to this as a belt slap. This may seem like a savings, until they call back with the real cost.

Perhaps worse is only replacing the belt, only to have another component fail. For instance, if the water pump fails, ten-thousand miles after the timing belt is replaced. Repair means another full disassembly and the water pump can actually cause the replaced timing belt to break.

Another problem is a seal that starts to leak after timing belt replacement. The seal could have been replaced for a minimum cost while the timing belt was off. Now many of the same components must again be removed. Worse, the oil from the leaking seal can ruin a new timing belt. Remember, you never get more than you pay for.

Upper view partially disassembled timing belt

Lower view, partially disassembled timing belt

A timing belt is not the same as a serpentine belt 

Vehicles are also equipped with exterior belts and serpentine belts.  Folks sometimes confuse these and think replacing the outside belts is the same as the timing belt.  The timing belt is inside of the engine.  If your vehicle is seven years old or older, check to see if it is equipped with a timing belt.  If so, be sure the timing belt has been replaced.  This can save an engine, in many cases.

Post or Read Comments (0)

 

Registered visitors are always invited to leave their comments and thoughts by using the form above. If you need to you can login here or register here.

You can also win a free AGCO coffee cup, by reporting any errors you find, with this form.

Whitey, I Know That. We Used To Run Dodge Aires Cars (Had 3 Of Them). They Were Fantastic Cars And Had T-Belt 2.2L 4s And I’d Run Them Until The Belt Snapped.

I only ever had one do that. I could actually be a contender in this contest because we got over 200,000 miles out of these cars, but I don’t remember the specifics (we’re talking 82, 86, 88 models), so I will take myself out of the running.

I think as the race for MPGs has heated up there are far more cars that run timing belts that are Interference Engines, as manufacturers try and wring out every bit of HP and MPG from small displacement powerplants.

You remided me of when I replaced that Aires timing belt in the driveway. It was pretty easy. Since I didn’t have a proper belt tensioning tool, I notched a wooden stick of wood and hooked a fish scale to the end. On a running Aires, I removed the plastic belt gaurd and using the jury rigged “tensioning gauge,” I noted how much pull it took on the fish scale to twist the belt 90 degrees between the two most distant pulleys, I believe it was 8 pounds. Then I set the new belt on the other Aries to 8 pounds. It ran forever.

We’re talking the 80s, timing belts were fairly new on cars and we live in the sticks in the middle of nowhere. A man’s got to do what a man’s got to do.

Damn, those were great little cars, comfortable, reliable, durable, easy to drive, roomy, decent trunk, ugly, and great MPG (30ish).

CSA

Maintenance

What Is a Timing Belt? And When Should You Replace It?

Timing is everything. For jokes, music, cooking, dating—even engines! That’s because your car’s engine relies on a timing belt to stay in sync. The timing belt makes sure everything in the engine is operating smoothly, keeping you safe on the road.

Replacing the timing belt is an important maintenance item! So, if you own a car, you should understand how a timing belt works and when to replace it.

Read: The Car Maintenance Checklist Every Driver Needs

What is a timing belt?

Think of a timing belt like a bike chain for your vehicle—it keeps all the internal moving parts of an engine in sync. It also sometimes powers the water pump, oil pump and injection pump.

The timing belt is a rubber belt with hard teeth that interlock with the cogwheels of the crankshaft and the camshafts. It synchronizes the movement of the crankshaft and camshafts. This ensures that the engine intake and exhaust valves open and close in time with the pistons. If the crankshaft and camshafts are not operating in unison, the vehicle will not run correctly.

If the intake valves open too early, there may be too much fuel-air mixture flowing into the engine combustion chamber, leading to poor combustion and power loss. And if the exhaust valves open too early, the combustion chamber will lose pressure and cause a power loss. If the engine components are very out of sync, they might collide and damage each other, resulting in costly repairs.

Timing Belt vs. Timing Chain

Depending on your vehicle model, you might have a timing chain instead of a timing belt. A timing chain functions the same as a belt, but it is metal instead of rubber. Because they are lighter and quieter, timing belts became popular to use after they were introduced in the 1960s.

Thanks to design improvements and a long lifespan, many modern cars have returned to using timing chains instead. If your car has a timing chain instead of a timing belt, you may be able to go longer before replacing the timing chain. As always, check your owner’s manual or give us a call to be sure.

When should you replace the timing belt?

It’s important to replace your timing belt at the mileage intervals your vehicle manufacturer recommends. Every manufacturer is different, but typically, it needs to be replaced every 60,000–100,000 miles. The recommended interval for your specific vehicle can be found in your car’s owner’s manual.

Because the timing belt is made of rubber, it will wear down over time and eventually break. When it breaks, the engine will stop running or the components will be out of sync, damaging the engine.

If you don’t replace the timing belt at the recommended time, you could end up with total engine failure, broken or bent valves, cylinder head or camshaft damage, and piston and cylinder wall damage. This is not the type of situation where it’s safe to think: ‘If it’s not broke, don’t fix it.’ Replace the timing belt according to the manufacturer’s maintenance schedule to avoid thousands of dollars repairing or replacing your engine.

8 Signs That It’s Time to Replace the Timing Belt

Often, there aren’t any warning signs before a timing belt breaks. But here are some possible indicators that it might be time to replace your belt:

• Decreased engine power
• Overheating
• Vibrating or shaking
• Trouble starting the vehicle
• Squealing or rubbing noises from the belts
• Ticking noise coming from the engine
• Leaking oil
• Check Engine Light

While your vehicle is in for service, we recommend also replacing the water pump. The water pump usually has a similar lifespan and is easy to access when the timing belt is off. That way you save money on labor costs.

Read: What Is a Serpentine Belt & When Should You Replace It?

Timing Belt Repair & Replacement at Virginia Tire & Auto

Replacing the timing belt is an expensive service. It is an intricate, labor-intensive process that can take 4–8 hours, depending on the vehicle. But replacing the timing belt before it breaks will prevent engine damage and save you money in the long run. If you’re unsure about your belt needs to be replaced, stop by Virginia Tire & Auto today.

Our expert ASE-certified technicians will examine your vehicle, identify any damage to your belt, and replace it with quality service at an affordable price. If you do need work done, our timing belt replacement service comes backed by our 2-year/24,000-mile service warranty. Click HERE to schedule a check-in time at one of our convenient locations!