Maintenance guide · Glass Box Diagnostics
A glazed, cracking belt at 90,000 miles is due — that is real. But the belt that squeals at startup on a 60,000-mile car is usually telling you about a failing tensioner, a dragging idler, or an AC compressor bearing, and replacing the belt alone buys silence until everything else chews through the new one. The belt is often the victim, not the culprit.
Honest interval
Inspect 60k, replace 90–105k
Cost when it IS due
$100–$250 belt-and-tensioner job done right; $120–$180 belt alone (which is often just re-arranging the problem)
EPDM belts do not crack like old neoprene ones — they wear quietly, so looking for cracks is a 1995 test on a 2020 belt. Manuals now say inspect at 60k and replace at 90–105k, and the honest trigger is rib-height wear and tensioner travel, not the calendar.
Three checks with the engine off: ribs measured against the wear grooves, the tensioner arm's travel mark (a belt fluttering at rest means the tensioner is dying), and spinning each idler by hand for roughness. All of it is a two-minute free inspection — which is exactly the kind of inspection that gets skipped in favor of just selling the belt.
The $99 belt special that replaces the belt while the grumbling tensioner stays in place — plus its evil twin, the since-we-are-in-there full package of belt, tensioner, idler, water pump and coolant service on a car where the belt was the only measured failure.
A stethoscope walk of every pulley at idle separates squealer from victim; belt flutter at rest and an offset wear pattern on the old belt name the tensioner without a parts catalog.
Codes a menu might cite to justify this service
If it's actually broken, price the real repair
Lights that make this service urgent
Symptoms that point here
Is it due on YOUR car? Settle it with a measurement, not a sticker.
Intervals on this page are manufacturer schedules and honest street pricing for independent shops, published as a benchmark — not a quote for your car. The line item nobody else prices: whether YOUR car is actually due. A flat $150 diagnostic answers that with evidence instead of a calendar.