If you’ve ever peaked under the hood of your vehicle you’ve probably noticed a long, winding belt that runs across a bunch of different sized pulleys – all in different locations – on your engine.
This is the serpentine belt, and it’s a whole lot more important than most people realize – with many of them only discovering after the serpentine belt breaks or comes flying off just how important it really is!
In the rest of this detailed guide, though, we are going to run through almost everything you need to know about the serpentine belt.
We cover:
- What the serpentine belt is and why it’s so important
- Why serpentine belt fail in the first place and
- How long a car can run without serpentine belt
… And more!
Ready to jump right in?
Let’s do this!
Serpentine Belt 101
Your serpentine belt is a (relatively) modern advancement in the world of automobile engineering.
In the “old days” of automobile engineering, every single engine accessory – water pumps, radiator fans, power steering systems, etc. – all ran off of their own independent else and pulleys.
The trouble with this, though, was that these pulleys and these belts could be next to impossible to get to when they need to be repaired or replaced.
On top of that, keeping all of these accessories operating in sync with one another (without drawing too much power from the engine) could be a real nightmare, too.
The serpentine belt innovation changed all of that completely.
Now instead of having individual belts responsible for powering those accessories a single belt ran like a serpent throughout the engine, connecting all of these accessories together, maintaining tension across the board, and making it a whole lot easier to optimize these components.
You also have the big advantage only replacing a single part when one of your accessories go on the fritz!
Why Do Serpentine Belts Fail?
Of course, like any other part in your vehicle serpentine belt are subject to wear and tear and have the potential to break down, come apart, and fail.
If that happens you’re going to be dealing with a couple of major headaches, including:
- An almost immediate loss of all of your power steering assistance
- Your coolant isn’t going to pump through your engine bay, running the risk of things overheating
- Your air conditioning is going to stop working instantly and
… You even run the risk of your vehicle going into “limp” mode to protect itself until the serpentine belt issue can be fixed.
Limp mode occurs when your onboard computer determines that something is wrong in the engine bay, disabling a lot of core systems (and causing your vehicle to literally limp along) to protect against more extreme instances of engine damage.
You’ll notice when you go into limp mode almost right away!
There are a couple of different reasons that serpentine belt fail.
For one thing, normal wear and tear inevitably catch up to serpentine belt just like it will on every other component in your vehicle. Most serpentine belts are recommended to be replaced somewhere around 80,000 miles or so. You’ll want to replace them every 80,000 miles, too.
Loose tensioner arms, loose pulleys, bearings that are out of spec, and a whole host of other issues can cause your serpentine belt to be thrown from its positioning or to frazzle, shred, and split completely in two.
You might even just be dealing with a serpentine belt that was faulty from the manufacturer and destined to blow up sooner than you would have expected as well!
How Long Can a Car Run without Serpentine Belt?
The good news, though, is that your vehicle isn’t going to come to a screeching halt the moment that the serpentine belt becomes compromised.
No, it’s not recommended to drive very long – or very far, or even very fast – with a vehicle that has a serpentine belt that’s become compromised. But you are going to be able to drive at least a little bit.
Most manufacturers recommend that you not drive any more than 20 minutes on a serpentine belt that isn’t working the way it should be.
Mechanics will tell you that you can (usually) stretch that 20 minutes of emergency drive time out to between 60 and even 90 minutes – depending on how regularly you kept up with important routine maintenance like coolant refills and oil changes.
The number one priority here has to be keeping your engine from overheating.
As soon as that serpentine belt falls apart your water pump is going to stop moving coolant throughout the system. Your radiator fan is also going to stop working the way it should.
This means you’re looking at a serious overheating problem, particularly if you are driving your vehicle around in warmer weather. If you’re driving in the summertime you can get into a real dangerous (and potentially expensive) situation faster than you would have thought possible.
Can a Vehicle Be Started without a Serpentine Belt?
Yes, believe it or not, you actually are able to start up a vehicle without a serpentine belt – but again you aren’t going to want to run it for very long in this condition.
The reason you’re able to fire up your vehicle without a serpentine belt is because your starter motor and your ignition system is not connected to this belt. These core components are independent of the serpentine system.
Is It Safe to Drive without a Serpentine Belt?
While it’s not necessarily unsafe to drive around without a serpentine belt, it certainly isn’t something most would recommend.
Again, if you absolutely have to drive without a serpentine belt working the way it should you want to limit your drive time to 20 minutes (or as close to that as possible).
You absolutely, positively do not want to cause your engine to overheat. That’s a fast way to seize your engine – necessitating a full tearout and replacement (and possibly totaling your vehicle in the process).
If you absolutely, positively must drive with a compromised serpentine belt keep your speeds slow and limit your time driving.
Get to a mechanic (or have the vehicle towed there) ASAP.