Drive Belt Tensioner Replacement
How are drive belt tensioner issues diagnosed?
Diagnosis of a failed or failing tensioner requires removal and inspection. This hands-on inspection will allow the servicing technician to check the pulley by hand for signs of grinding, looseness, chirping, and rattling. Upon inspection of the belt tensioner, a well-trained technician will notice these flaws, and may recommend immediate replacement of the tensioner. If the engine is running and the technician notes that the tensioner is bouncing back and forth due to a failed spring, they will recommend replacement.
How is a drive belt tensioner replaced?
Removal of the drive belt by releasing the tensioner is the first step. On spring tensioners, removal may require the tensioner be pinned in place to prevent tension from returning as soon as it is released. The tensioner is then removed, and replacement is the reverse order. The tensioner retaining fasteners must be tightened to manufacturer's specifications to prevent damage to the mounting bracket or timing cover, and non-spring tensioners will be manually adjusted. Spring tensioners only need to be released, and they will adjust automatically as the engine is running.
RepairPal Recommendations for drive belt tensioner issues
Since this service requires removal of the serpentine belt, it may be recommended to replace the belt unless recently replaced. This is much more cost effective than returning for the same service after a partial service interval has elapsed. Frayed or cracked belts should be replaced without regard to current age or mileage, as they are near the end of their reliable service life.
What to look out for when dealing with drive belt tensioner issues
Replacement may require the removal of other engine accessories, or even a motor mount. This is because these vehicles will have reduced working room, or the retaining bolts may be located behind other components.
Can I replace the drive belt tensioner myself?
The novice DIYer would be perfectly comfortable replacing the belt tensioner and pulley, but a torque wrench with small enough increments must be used to avoid damaging the engine accessory mounting bracket, or timing belt cover, whichever the particular vehicle uses. If a torque wrench is unavailable, do not attempt this repair, as the damage caused by over-tightening, or under-tightening can be very costly.