Timing Belt Tensioner Buyer's Guide
The roles of the timing belt and its tensioner intertwine literally and figuratively. The belt makes sure that the crankshaft and camshaft operate in sync for smooth engine operation while the timing belt tensioner ensures the belt stays taut and tight, preventing any slack that may cause the length to slip.
When you replace the timing belt, it’s also recommended to get a new tensioner for best results. This buyer’s guide can help you select the right replacement for your car’s belt tensioner.
What is a timing belt tensioner?
The timing belt tensioner controls the amount of tension in the belt. Its four parts are the base, the tensioner, the tensioner pulley, and the tensioner arm.
As its name implies, the tensioner pulls on the timing belt to keep it tense and prevent it from slipping. Many tensioners use torsion springs that apply mechanical force on the belt, but some rely on hydraulic-powered clamps.
Below it sits the tensioner arm. This component serves to counter the pulling motion of the tensioner so you can adjust, remove, and replace the timing belt when necessary.
The tensioner pulley guides the belt to its proper destination. A slack belt can slip out of this pulley and cause problems.
Finally, the base bears the combined weight of the other parts and holds them in place. It can withstand the vibrations produced by the running engine and the shocks caused by driving over uneven ground surfaces.
Symptoms of a bad or failing timing belt tensioner
The timing belt tensioner keeps the timing belt at the right level of tightness. Otherwise, the belt will slacken until it slips up and misses one or more teeth on the crankshaft or camshaft, disrupting the valve timing and throwing off the engine’s operation.
A malfunctioning tensioner can put too much pressure on the timing belt until the latter stretches. This causes much the same problems
When the belt tensioner wears out or breaks down, it may cause these warning signs:
- The belt makes grinding or roaring noises
- Loss of synchronization between the crankshaft and the camshaft, leading to poorer engine performance
- The Check Engine Light activates
- The PCM logs trouble codes associated with the camshaft or crankshaft sensors
- The engine makes slapping or scraping noises
- The engine’s RPM may abruptly climb as your car speeds up because it isn’t accelerating smoothly
How much does a timing belt tensioner cost?
Factors like the parts manufacturer, the number of parts in a set, and the location of the part affect the cost of the replacement part. A timing belt tensioner can go for around $5 up to roughly $310. You can get individual tensioners, a set of 2, 3, 4, or 5 units, or a replacement kit that includes other parts like a new timing belt.
Replacing an old or broken timing belt tensioner
Even when the engine isn’t running, the timing belt tensioner is always working to ensure the timing belt doesn’t slip. The wear and tear from constantly applying pressure to the often-moving belt can push the tensioner past its design limits.
Once you catch wind of any symptoms linked to a bad or failing tensioner, replace the faulty component as early as possible. Otherwise, its negative effects on other engine parts can cause failure in those components.
If you replaced the timing belt, you must also install a new tensioner, even if the current unit looks fine. The timing belt tensioner often takes other parts with it when it finally breaks down, so replacing it at the same time as the timing belt will reduce the risk of a domino effect.
Selecting the best timing belt tensioner
So your car’s old timing belt tensioner needs a replacement because of old age, malfunctions, or your planned purchase of a new timing belt. You have plenty of options to choose from, so how can you pick the best tensioner for your car?
Torsion spring type versus hydraulic type
Many timing belt tensioners use torsion springs to apply mechanical pressure on the belt. They are simple, reliable, and fit any budget.
Other designs take advantage of hydraulic pressure. These complex hydraulic tensioners cost more and take up more space in the engine, but they also deliver greater performance.
Adjustable tensioners versus automatic tensioners
If you own an older vehicle model, it may have an adjustable timing belt tensioner. This type requires manual adjustment of the tensioner after returning a slipped belt to the tensioner pulley.
Later vehicle generations switched to automatic timing belt tensioners that handle the chore of readjusting loose belts.
No car part enjoys compatibility with all vehicles, and this holds true for timing belt tensioners. Older vehicles that use adjustable tensioners may not accept the newer automatic tensioners, while a hydraulic tensioner may not fit in the limited engine space that once held a torsion spring tensioner.
To help you find the right fit for your car, our online shop comes with a convenient filter bar feature. By entering your vehicle’s year, make, and model, you can quickly browse the wide selection of timing belt tensioners we carry.
OEM parts versus OE parts
The simplest way to ensure the new timing belt tensioner’s compatibility is getting an exact replacement from an authorized parts shop. Also called Genuine parts, these Original Equipment Manufacturer (OEM) parts exactly match the stock parts they replace.
If you own an older vehicle model no longer produced by its manufacturer, the supply of OEM parts designed for that model may have dried up because of lack of official support, making it much harder to replace faulty parts like a timing belt tensioner.
Original Equipment (OE) parts offer a flexible alternative to OEM components. Produced by other companies with no direct affiliation to the vehicle’s original manufacturer, these parts appear in every store’s catalog and deliver roughly the same performance as Genuine parts.
Some OE parts improve on known defects of the OEM counterparts. You may even find components deliberately designed for compatibility with discontinued vehicle models to help keep those old cars on the road.