The factory recommended "inspection" interval for the timing belt on this particular engine is 30,000 miles, and the recommended replacement interval is 60,000 miles.

Many motorists are unaware of these recommendations and typically do nothing until the timing belt fails -- which is bad news because the 1.6L E-TECH II engine is an interference engine. If the timing belt breaks, one or more valves will hit the pistons and damage the engine. The repair may require replacing one or more valves, possibly a piston or two, and maybe even the entire cylinder head. The repair bill can easily total $1,600 to $2,000 for parts and labor.

PREMATURE TIMING BELT FAILURES

Some of the OEM timing belts on these engines have not even made it to the 60, 000 mile mark. There have been numerous reports of timing belts failing at 40,000 to 50,000 miles.

In October, 2006, General Motors issued a technical service bulletin (TSB 06-06-01-021) offering motorists a free "goodwill" replacement timing belt (parts only, labor not included) for vehicles with 30,000 to 55,000 miles on the odometer that still have the original timing belt. GM said they wanted to examine the original belts for possible defects. The free belt offer is for a limited time only, and does not apply to vehicles with more than 55,000 miles on the original belt. GM says it is the vehicle owner's responsibility to maintain their vehicle properly, and to have the timing belt inspected at 30,000 miles and replaced at 60,000 miles. Consequently, if the belt has never been replaced and it breaks, so sad too bad.

CHEVY AVEO TIMING BELT CHECKS

Like all timing belt replacement jobs, the timing belt cover on the front of the engine will have to come off. But first you have to get some other parts out of the way. Start by disconnecting the battery. Then remove the intake air temperature (IAT) sensor connector, the air intake tube from the throttle body, the breather tube from the valve cover, and the air filter housing. Next, remove the right front wheel so you can remove the splash shield behind it.

With these other parts out of the way, you can remove the serpentine belt, and then the crankshaft pulley bolt and the crankshaft pulley (you will probably need a puller to get the pulley off the nose of the crankshaft).

Next, you can remove the upper timing belt cover, then the lower cover. The power steering pump bolts will also have to come out.

Put the crank pulley bolt back into the end of the crankshaft, and rotate the crank as needed to align the mark on the crankshaft timing belt pulley with the notch on the bottom of the rear timing belt cover (the mark should be straight down).

Now you can loosen the water pump bolts and rotate the pump counterclockwise with special tool J42492-A (KM-421-A) to relieve tension on the belt. The timing belt can now be slipped off. Don't disturb the position of the crankshaft or camshaft pulleys until the new belt is in place.

As we said earlier, it is a good idea to also go ahead and also replace the water pump, idler and tensioner pulleys at this time, too.

INSTALLING THE NEW TIMING BELT

The following is taken right from the Chevy service literature:
1. Align the timing mark on the crankshaft gear to the notch on the bottom of the rear timing belt cover.
Important: Ensure that the exhaust camshaft gear dowel pin (1) is approximately in the 11 o'clock position.
2. Align the timing marks on the camshaft gears.
3. Install the timing belt.
4. Rotate the coolant pump clockwise using the J 42492-A.
5. Rotate the coolant pump clockwise until the adjust arm pointer of the timing belt automatic tensioner is aligned to the notch in the timing belt automatic tensioner bracket.
6. Tighten the coolant pump retaining bolts.
7. Rotate the crankshaft 2 full turns clockwise using the crankshaft pulley bolt.
8. Loosen the coolant pump retaining bolts.
9. Rotate the coolant pump until the adjust arm pointer of the timing belt automatic tensioner is aligned with the pointer on the timing belt automatic tensioner bracket.
10. Tighten the coolant pump retaining bolts. Tighten Tighten the coolant pump retaining bolts to 10 Nm (89 lb in).

GM recommends rotating the crankshaft twice after the initial adjustment to make sure all of the timing marks are correctly aligned. They also recommend loosening the water pump bolts, and rotating the water pump clockwise again to make sure the tensioner pointer lines up with the notch in the bracket. You don't want a loose tensioner because it might allow the belt to slip and jump time. You also don't want the belt too tight because that can shorten the life of the water pump shaft bearings and seal as well as the timing belt.

Once the belt has been properly tensioned and double-checked to make sure the timing marks are correctly aligned, you can put everything back in the reverse order it was taken apart. The recommended torque for the crankshaft pulley bolt is 70 ft.lbs. (95 Nm) plus and angle turn of 30 degrees followed by a final turn of an additional 15 degrees (use a torque wrench and angle gauge to be accurate).

Also, when you remount the right front wheel on the car, use a torque wrench on the lug nuts.

Finally, inspect the timing belt after 30,000 miles, and replace it again at 120,000 miles, and again at 180,000 miles.