Odd serpentine belt failure

2003 Passenger Van, 175,000 miles

It has been written in the forum that serpentine belt breakage is a rare event. Last week my belt shed a 1/4 inch strip (lengthwise), which promptly got wrapped around the fan pulley. (It had been installed about five years, 40K miles ago, but a recent visual inspection revealed no cracks)

This happened at start-up, so the engine was shut off before further damage. Is this a "normal" sort of failure, or does it suggest some pulley is failing or out of alignment (they all spun freely when the old belt was replaced). Thanks for any insights!

Does your tensioner arm run true? Any sharp edges on the pulleys?

Is the alternator one-way clutch seized?

With the engine running watch the belt. Does it wiggle back and forth on the smooth pulleys? Does it jump a lot or run straight?

That is probably caused by an idler pulley going bad. Check them carefully before you install a new belt. A bad water pump could do that also, but they usually leak coolant long before they cause a belt failure.

Midwestdrifter said:

Does your tensioner arm run true? Any sharp edges on the pulleys?

Is the alternator one-way clutch seized?

With the engine running watch the belt. Does it wiggle back and forth on the smooth pulleys? Does it jump a lot or run straight?

Click to expand...

None of the above. Belt failure at 40,000 seems premature, unless the time element (five-years since replacement, including 3 years in storage) compromised the belt.

galvinize said:

... unless the time element (five-years since replacement, including 3 years in storage) compromised the belt.

Click to expand...

Storage may cause the rubber to take a "set". Tires sitting in storage sometimes deteriorate sooner than do tires seeing regular use. I imagine the same could apply to Poly V belts.

Longitudinal failure of the belt (strips of rubber vs fracture across the Vee's) is the typical failure mode. Visual inspection of the EDPM Poly V belts isn't a very effective method to determine belt condition. There are wear gauges, but those gauges may not be effective when applied to belts which see infrequent service.

Some info is in this thread.

80,000 miles/4 years has been mentioned as a suggested maintenance interval.

serpentine belt replacement
https://sprinter-source.com/forum/showthread.php?p=678885#post678885

vic