An engine’s timing belt runs between the crankshaft and the camshaft(s), ensuring that the valves open and close at just the right time. Timing belts typically have teeth, ensuring the coordination between the two shafts – literally their being “timed” together – remains extremely precise. In some vehicles, timing chains or gears are used, rather than belts. The former tend to be more durable, so owners of cars and trucks with belts sometimes need to schedule service for the fitting of a replacement.
But what are the signs it’s time for timing belt replacement?
The first, and most obvious, sign of problems is elongation; the belt stretches, in imperceptible but incremental amounts, until it becomes too loose to perform its function with precision. If you know your vehicle well, you may be able to detect elongation simply by pulling on the belt (with the engine switched off) and comparing its resistance to what you’re sure the “feel” should be. For most drivers, though, a quick inspection by a qualified mechanic is the way to go. In either case, if the belt has elongated, it has passed the end of its service life.
It’s always best to take a preventative attitude to vehicle component replacement, rather than address the problem after you’re stranded on the side of a highway (inevitably in the dark, when it’s raining and you’re miles from home or help). This rule is very applicable to timing belts, because in most designs of engine they’re on the outside, thus can be inspected for potential failure without any tools, and without removing any casings or components.
Look for material loss; the abrading away of the rubber and strengthening bands which comprise the belt as a whole. Remember, timing belts are likely to wear more swiftly under load, so vehicles which tow regularly, or carry heavy cargo, are more prone to this kind of wear. Also look at the edges of the belt, where abrasion can be caused by even miniscule bearing and/or pulley misalignment.
Cracks can occur on both the inside and the outside of the belt’s flat faces, while glazing – a shine or gloss caused by excessive wear and heat – only occurs on the inside. All of these visible cues are indications that timing belt replacement is overdue.
Noise and Vibration
Pilling is the creation of tiny bobbles of fiber sometimes noticed on sheets, for instance, that have seen a lot of use. Pilling can likewise occur around your timing belt, following separation of the fibers which make up the strengthening and tensioning ribs molded into the neoprene body.
These clumps can build up in the cross sections between the gripping ribs, and – less often – around the pulleys and shaft ends. The typical symptom for pilling build-up is unusual noises or vibration developing, particularly when the engine is under strain. Loss of internal strengthening material, of course, mandates timing belt replacement.
Cherry Hill Nissan is the premier NJ Nissan dealer serving Cherry Hill, Moorsetown, Marlton, Medford, Camden, and Philadelphia. While our dealership is primarily focused on sales and service of new Nissan autos, our factory trained Nissan technicians will be happy to discuss any timing belt issues regardless of vehicle manufacturer. Located at 2325 Route 38, Cherry Hill, NJ, our opening hours are 9:00 AM to 9:00 PM, Mondays through Thursdays, and 9:00 AM to 6:00 PM on Fridays and Saturdays (we’re closed on Sundays).