How are engine belts installed? How can I tell if the timing belt is too tight?

When installing an engine belt, such as a timing belt, you need to be very careful to ensure that the belt is properly installed and adjusted to prevent damage to the engine. Below are the steps for installing an engine belt and a guide on how to tell if the timing belt is too tight.

1. Engine Belt Installation Steps
a. Preparation
Make sure the engine is cool and the power is off.
Remove related external parts (such as the shroud) so that the belt and related parts can be seen.
Inspect the pulleys for signs of damage or wear and replace if necessary.
b. Loosen the tensioner
Find the tensioner for the belt and loosen the tensioner using a wrench or special tool to allow slack in the belt.
After loosening the tensioner, remove the old belt.
c. Install a New Belt
Follow the belt path diagram in the vehicle's service manual and pass the new belt around each pulley, making sure that the belt is aligned with the pulley teeth.
In the case of a timing belt, you must ensure that the camshaft and crankshaft are in the correct alignment (i.e. the timing marks are aligned), otherwise damage to the internal engine components will occur.
d. Adjust the tensioner
After installing the belt, readjust the tensioner. Make sure the tensioner pulley applies the proper pressure but is not over-tightened.
e. Check the installation
Turn the crankshaft manually (usually with a wrench) a few turns to make sure the belt is properly seated on all pulleys and there is no misalignment.
Reinstall the parts that were removed previously.
f. Start the engine
Start the engine and observe the operation of the belt to ensure that it is working properly without abnormal noise or jumping.
2. How to tell if the timing belt is too tight
The tension of the timing belt is very critical. Too loose or too tight will affect the performance of the engine or cause damage. The following are common ways to tell if the timing belt is too tight:

a. Manual inspection
In the middle of the belt (between the two pulleys), gently press the belt with your fingers. Usually, the belt should have a certain elasticity and be able to move down about 10-15 mm when pressed. If the belt can hardly move, it means it is probably too tight.
b. Listen to the sound
If the timing belt is too tight, a high-frequency "squeaking" sound may be emitted when the engine is running. This noise is usually caused by abnormal belt friction or increased pulley load due to excessive tension.
c. Check belt wear
A belt that is too tight can cause excessive friction, which accelerates belt wear. Check the belt surface for excessive wear, cracks, or obvious stretch marks.
d. Tensioner pointer check
Some engines are equipped with a tensioner pointer device that indicates the tightness of the belt. If the pointer shows that the belt is in the too tight area, you need to loosen the tensioner to adjust it.
e. Impact on engine performance
If the belt is too tight, it may put too much pressure on the water pump, generator, or other belt-driven components, causing them to operate improperly. This will be reflected in reduced engine performance or abnormal wear of certain accessories such as the generator pulley.
3. Ideal belt tension
The belt should not be too loose or too tight. The tightness should be just right to ensure that the belt can run stably on the pulley without slipping or damaging the bearing due to overtightening. If you are unsure, it is best to use a tension meter tool to measure the belt tension value according to the manufacturer's specifications.

Make sure to check and maintain the belt tension regularly, and adjust or replace it in time if abnormal conditions are found.