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2006 Hyundai Sonata V6 Serpentine Belt

Is it time to replace? There is a noise coming from the belt and when I listen with the hood up my best guess is that it’s the tensioner. I’m not sure if it is easy to replace or if that is even the problem. The belt looks fine. It allows me to twist it barely less than halfway so to me it does not seem loose. But in the rain last week got the battery light and lost power steering, power brakes, etc, then it went back to normal and hasn’t failed again since. The car has 131,000 miles.

Ideas? Is there a way to check the tensioner? It’s pretty tight in there. Or am I wrong as to what the problem is? The sound is a rubbing/slight clicking sound that is in time with the engine and you can hear it if you listen inside the car when the engine is on. The belt also seems to wander around on the tensioner just a little. One day it was about a mm in too much, a few days later, a few mm out, in relation to the pulley.

Thanks much in advance

also, it’s the V6

You can’t tell if a serpentine belt requires replacement by appearance anymore.

If the vehicle has 131,000 miles on it and it’s the original serpentine belt, I can assure you it requires replacement.


It most likely needs replacing. What does it sound like? and is the sound continuous or is it intermittent?

The way to test the tensioner is two-fold. One, it needs to keep tension on the belt to prevent slippage. A tension gauge can do this quickly. Second, the bearing for the pulley needs to be checked for noises and wear. If either is suspect, replace the tensioner. At 131,000 miles, I’d replace it with the belt just to not have a problem and do this job twice.

Losing power brakes is a mystery. Did the engine lose power, too?

It sounds to me like the OP simply experienced a temporary engine stall. That would explain all of the symptoms, including the loss of vacuum on the brake booster. I think the serp belt is the wrong direction to look.

I’d suggest starting with a check of the ECU for stored fault codes.
If any engine maintenance is overdue, it’d be a good time to get that up to date also.

Post the actual codes if you discover any. Many parts stores will check these for free.

Another idea, since it happened during rain, the belt might have gotten wet and slipped a bit. That would be a sign it either needs replacement or at least the tension checked. If this belt is original to the vehicle, at 130+K, me, I’d just replace it and be done with it. There’s probably some instruction somewhere on the internet on how to check a belt tensioner by using Google. A good time to do that is with the old belt removed, and before the new belt is installed.

If you want to narrow down where the noise is coming from you could use a length of old garden hose as a DIY mechanic’s stethoscope.

At the age and mileage and if the belt and tensioner are original then they’re due, or past due, for replacement.

Belt rubber can harden with age and lose it’s bite. Throw a little water on it and that likely created the problem the car had last week.

Thanks. Yeah, the consensus is to replace the belt, and AFAIK, it’s never been replaced (bought used from rental car company with 28K on it). It’s due/overdue for scheduled maintenance (last was before 120k) - only oil since. Googling around, changing the belt doesn’t seem too bad for someone like me who is only a step or two above novice.

But what about the noise? I’m fairly confident it is the tensioner itself… is that likely? Is that hard to replace? (BustedKnuckles and ok4450 suggested to do both, for good measure) is it that easy?

To answer some other questions:
JimFrost: sound was intermittent, but for the last week or two it’s pretty constant

insightful: I was on a dark highway in a moderate rain at night (you know, the only place a car has trouble :slight_smile: ) I clearly lost steering, saw the battery light, and when I slowed down it seemed harder to brake, but I won’t rule out that I didn’t imagine the brake issue in my moment of stress. The battery light went off about 15 seconds later, as I slowed down, killed the accessories and took the next exit. No problems after that. I’ve driven it normally since, though not through anything but light drizzle.

the same mountainbike: The engine has had a few codes since summer, but not any that night. P0023. I looked it up--
As I said, I intend to get it in the shop for scheduled maintenance, but I have to travel before I do that, so I’m trying to figure out what I should do right now. I can’t get a good assessment on the urgency of this code. Plus, if I can do some of the work beforehand and leave just the hard stuff to the dealer, I would prefer to do that. Short on $$ (everybody’s story) If that code is urgent, let me know and I’ll just go ahead and make an appointment, however.

In truth, this car has served me well–the only major failure its ever had is the fuel pump.

just want to add that I love this website… I get great advice here. Thank’s all.
Tom’s legacy lives on.

P0023. That description isn’t so helpful, eh? On many cars there are 4 camshaft position sensors for the combinations of intake/exhaust and exhaust bank 1/exhaust bank 2. 2 X 2 = 4. The factory service manual (or equivalent) would tell you which of the four this code refers to on your car. If you can’t get the info from Googling, your public library, an inexpensive subscription to AllData computer database for your car, as long as they aren’t busy, most dealership parts and service departments would look it up for you and print you out a diagram.

If you want to continue with DIY work on your car, other than oil changes and the like, simple stuff like that, you need access to the factory service manual or equivalent.