OEM Quality Tensioners & Pulleys for Trucks

How to Diagnose a Belt Tensioner on Your Car or Truck?

The function of the belt tensioner is something that applies a regulated amount of pressure to the belt , so it can spin all those pulleys as needed.

It’s going to be located in different areas depending on the vehicle ( some engine might run front to back , some even transversely). When you open the hood, you can see some of the major components that the belt rides along – like alternator, idler pulley, power steering pump, crankshaft , water pump if you have a hydraulic pump and you should also have a tensioner. Different types of vehicles have different types of tensioner. Generally there are 3 types of tensioners - the one is spring loaded, the one that is hydraulic and the one is self-adjustable type.

There probably some of the symptoms may occur, sometimes you hear a little bit of chirp coming from serpentine belt or even a squeal, especially if it’s wet outside. The reasons for that could either because your serpentine belt is in poor condition ( maybe it’s cracked or something like that), or it probably comes down to the tensioner itself (if serpentine belt is in good condition). Sometimes the tensioner isn’t functioning as it should, maybe it’s holding too much tension force on the belt which going across all the pulleys, you may also hear some bearing noise coming from alternator, power steering or idler pulley. Also , if the self-adjusted tensioner isn’t holding enough tension to the belt, you could also hear some squealing noise, esp. In moist condition.Sometimes if you notice the alternator isn’t charging properly, it probably because the loosen belt doesn’t apply proper amount of tension.

There is a simple to way to check whether the self-adjusting tensioner work well or not. That is grab onto the belt and give it a nice tub, if you don’t see the tensioner is moving, then you know it’s probably frozen. If you see the tensioner moving but it doesn’t fully retract to the point where it puts proper amount of tension on the belt, it could also be bad. So, if you find that you have a tensioner issue with your vehicle (putting too much tension or  even not enough), you’re more likely going to fix it ASAP.
There should be bearings inside the pulleys, sometimes if the belt pulling too hard on pulleys, it’s gonna put extra pressure on the bearings inside pulleys, in which case, it’s going to cause damage overall.

Now, you’ve checked the belt tensioners (whether it’s frozen or too weak), more than likely there is going to be damage that’s been done to your serpentine belt as well.  The next thing you need to do is inspect that serpentine belt and make sure that it’s in good condition . Remove the belt and check the ribbed area on the belt to see if it’s cracked or deeper. Because if the grooves getting worn , it’s gonna cause an issue.

Technicians may advise you to replace the belt when you planned to replace the worn tensioner. Because more than likely if the tensioner is damaged, it’s probably caused some damage to the belt as well.