Hi,

Read several things.

I got a truck, has 138K miles.

Serpentine belt, pulley's and tensioner all original equipment according to the maintenance records.

When should the belt be changed?

The tensioner doesn't appear to have excessive slop in it with the engine running (its not bouncing wildly).

Should I change them all and why?

 

They make a serpentine belt wear gauge that's sold at most auto parts stores. If you take the belt off just turn the pulleys and tensioner by hand and if they don't turn smoothly with no resistance replace them.

 

I replace my serpentine belts at around 70,000 miles -- probably could get a lot more out of them, but prefer to be on the safe side with a relatively low cost item.

 

Thanks for the advice guys. I think this gets me what I need.

 

I don't let mine go past about 60k. They only cost around $20 and are easy to replace.

 

It looks like some of us think the same. It's cheap enough, 60-70k is a good number.

 

The MotorCraft Serpentine belts are quality pieces . I've seen some with over 200K on them. Personally any belt over 100K is on borrowed time.

 

I don't remember the mileage on the belt but the belt on my 2000 5.4 started making noise on cold startup in a Wisconsin winter. Replacing the belt got rid of the noise.
I usually replace them at about 60k miles as preventive maintenance.

 

Serpentine belts are cheap, but I see no reason to change them out more than once every 100K miles. The belt I took off at 100K looked like it would have gone another 100K. I didn't change the auto-tensioner or idler pulleys either, as they appeared to be fine. Worst case is that one breaks and I install a new one with minimal fuss.

 

I replace mine when the cracks go into the main backing part of the belt. Small cracks in the ribs are not serious. Also change the tensioner at the same time, even if it seems to be good.

 

I ran my OEM belt for 125,000, replaced it with a Gates belt at O Reilly and now sitting at 235,000. I'll check mine once I hit 275,000, as the Gates are supposed to last 200,000-250,000.

 

I have a 2006 with 125k miles, original belt.

I plan to change mine this summer, but like stated by many I have no issues with mine as is.

 

If I was going to run my belt any longer than 60k, I'd definitely keep a spare belt in the truck with me. They're cheap and not hard to replace. Definitely not worth the hassle of running it till it fails.

 

I replaced the belt and tensioner. The belt cracking was through the ribs and into the backing of the belt in several places but was was not easy to see when on the truck. belt was pretty stretched as well. Once off it was clear that I was driving on borrowed time.

The tensioner was replaced as well. Total belt and tensioner was about a 10 min job.

Gates belt and tensioner used for both.

 

It's funny almost, I'm on my 4th belt at 106k. Bad luck I guess.

Replaced belt at 60k, at 70k the alternator pulley siezed and ruined the belt so I replaced the alternator and belt. Last summer, the ac went out and melted the belt slightly, so the ac compressor and belt were changed yet again.