Debi McConnell, owner, Medi-CAR Auto Repair

Timing Belts…does your car have one? If yes, are you aware of when it needs to be replaced according to manufacturer recommendation? Do you know if your engine is an interference engine?

If you don’t know these answers, don’t feel bad. Before I bought an automotive shop I had no clue. Hopefully your trusted automotive adviser is letting you know what maintenance is required at the different mileage intervals.

Here are some questions I had:

What is a timing belt? Can’t you look at it like the other belts to see if it’s cracked or ready to break?
• What do you mean it’s an interference engine and if the timing belt breaks it can damage the engine?
• Why do you recommend to replace the water pump at the same time? The dealer quotes a price without the water pump.
• Do I have to have all those gadgets like the hydraulic tensioner?

The Role of the Timing Belt
The timing belt is a small rubber belt that connects the crankshaft to the camshaft, controlling when the valves open and close. Timing belts are developed to be strong and durable, but they will eventually wear out. When the belt breaks, the valves won’t close in time, and the pistons hitting against them begin to cause immediate engine damage.
Sometimes there are symptoms that a timing belt is compromised. But most often, there are NO symptoms of a compromised belt. It just wears out and breaks. More unfortunately, access to the belt is difficult since it sits under a large timing cover that is hard to access and they tend to wear on the inside—which cannot be visually inspected without removal.

Broken timing belts:

If your engine is an interference engine, it means that when the timing belt breaks, the valve and piston will “interfere” and cause engine damage (major repair). But what if you find out you have a non-interference engine? No, you cannot wait until it breaks because 1) it could leave you stranded and 2) your engine could have dual cam heads and the valves could interfere and cause engine damage.

Water pump replacement and other timing components in a kit:

Yes, there are some shops and even your dealer who will quote the job at a much lower price because they don’t include the water pump or hydraulic tensioner. The Medi-CAR opinion is to replace the water pump at the same time as the timing belt. The water pump does wear out (100k is a long life for a mechanical part) and the labor cost is usually the same because the water pump is run by the timing belt so when a water pump is removed so is the timing belt. I don’t mean to be suspicious of other shops but it just doesn’t seem nice to charge 5 (or more) hours to replace the timing belt and charge the same 5 hours again in another 20K miles to replace the pump, if it should fail.

The hydraulic tensioner, camshaft and crankshaft seals are other crucial parts of the repair because they wear out as does any mechanical part, and the labor is the same cost wise to you, just like with a water pump. This can save you from break downs, oil leaks, and further cost in repairs down the road.

So what does all this mean?

In the olden days—yes, in MY youth, you didn’t keep your car much over 100,000 miles. (I remember being in the back seat of the family station wagon while we all watched our speedometer turn over 100,000.) This is not the case now. A well-maintained car should be expected to reach 200,000 miles and more. We service quite a few vehicles into their 300K!! But maintenance is crucial to meeting these goals

Watch the video on this page for a visual description of what the timing belt does–


Car mechanic replacing timing belt at camshaft of modern engine