What’s in a Belt?! Cambelts, Timing Belts and Wet Belts
What’s in a Wet Belt… Cambelt or Timing Belt?
Cambelts, Timing Belts and Wet Belts… Do they hold everything together and what happens when they don’t?! Which do you have? Neoprene, metal or rubber?!
Whilst manufacturers consider wet belts a critical component of modern engines, many drivers may not be familiar with the concept and there is a lack of widespread knowledge about the maintenance and potential risks associated with any belt.
What are Cambelts, Timing Belts and Wet belts?
They all do the same thing! All car engines perform the same purpose, but are configured slightly differently to get the performance out of the car in the way the manufacturer intended.
Most belts are positioned at the front of the engine and they synchronise the rotation of the crankshaft (that controls the drive and wheels of the car) and Camshaft (which controls the opening and closing of the valves in the cylinder head). The operation of the valves is a crucial part of the engine and needs to be precisely timed for:
Performance – valve timing ensures that the cylinders receive the optimal amount of air and fuel for combustion, maximising power output.
Fuel Economy – Efficient valve timing allows the engine to breathe more easily and consume less fuel.
Emission Control – Precise valve timing helps minimise exhaust emissions by ensuring complete combustion and reducing unburned fuel.
Types of Belt
Toothed belts were invented in the early 1940’s and used in textile mills. This was developed and the first belt was introduced into a 1954 race car. Car makers began to widely adopt cambelts in the 1970’s, made from Neoprene or Nitrile rubber. In the 1990’s timing chains were favoured as they were thought to require less maintenance and be more reliable, but they were not without issues: chains need regular lubrication and prone to breaking tensioners. So, some manufacturers retained the more affordable option of a belt whilst others retained chains.
Since 2008, some manufacturers have replaced timing belts or chains with wet belts. These are situated within the engine and lubricated with oil as it moves, allowing the belt and the engine to run more smoothly. It reduces friction and cuts emissions and helps the belt last longer, so better on our pocket and the environment. However, these too need more maintenance and replacement than originally thought.
Why are Wet Belts controversial?
The wet belt is continually in contact with the oil, it can cause the belt to degrade more quickly, and expediated if the wrong oil is used or the vehicle is not maintained properly.
All belts degrade gradually, but this one does so within the engine. Therefore, any particles released are circulated throughout the rest of the engine system. This can block or damage crucial engine parts causing blockages in the system that prevent the oil from circulating, causing engine failure.
What happens when they go wrong?
All belts deteriorate over time. They may start slipping as each ‘tooth’ on the belt wears and rounds. They may stretch over time and become loose. If you are fortunate, you may experience poor engine running or any of the symptoms below. However, it is more likely that the belt will fail with no symptoms or any obvious signs, little or no warning.
- Engine bay noises – squealing, grinding or rattling noises
- Engine light – comes on
- Low oil pressure light – comes on
- Engine misfiring
- Engine running poorly
What’s the risk?
If it deteriorates to the point of failure, vital engine components are at risk and it can have a catastrophic (and expensive) consequence.
- Engine damage– if damaged, the pistons in your engine can collide with the valves, and break or bend them
- Poor performance– you’ll notice reduced power due to the belt being worn or stretched. These symptoms usually present prior to the belt breaking or your engine sustaining major damage.
- Poor fuel economy– if experiencing reduced performance, then it’s very likely that your fuel won’t last as long, and you’ll have higher emissions
- Expensive repairs– worn or broken cam belts can cause extensive engine damage, sometimes to the point where the better option is to replace the entire engine, which could set you back quite significantly
So, it is crucial that the condition of your belt is regularly maintained and replaced to manufacturer guidelines. However, even the manufacturers are beginning to acknowledge that the intervals are possibly too long on wet belts.
Can I replace the belt myself?
As our pockets are continually stretched, it is tempting to see if you could do the job yourself. However, we would guard against it. The belts are so finely tuned, that it really takes a professional with the right equipment to ensure your safety.
Despite being quite common, many mechanics are much less familiar with wet belts than other types of belts, meaning issues can be harder to find and fix. It is also a messy and time-consuming job, so it is work some will also turn away. This lack of time, knowledge and skill required to resolve the issue can make repairs more difficult and costly.
How can you preserve your engine for longer?
Regular inspections: Many motorists complain that their wet belts failed or needed replacing before the change interval stated by the manufacturer, so get the belt replaced sooner.
Use the right oil: Using the wrong oil degrades the belt faster. Check the handbook for your car or contact your garage to get the most up to date advice.
Replace the belt before the change is due: Get ahead of the issue by replacing the belt earlier than the manufacturers recommend, and at the very least, at the first sign of deterioration.
Over to you….
So, recognising how important belts are, it is best to look after them well. They are right at the centre of your engine and control the way your car performs. If they break, it can be expensive to correct, or leave you without a car.
Let’s leave you with a quote from Mark Barclay, Head of Ecommerce at My Motor World :
“Without regular inspections and proper maintenance, wet timing belts can be an engine killer. To avoid costly repairs, owners of cars with this type of belt really have to be on it with their maintenance schedule. It might be annoying and expensive to keep checking and replacing the timing belt and changing the oil, but it’s still cheaper than a new engine — or even a new car. It’s a case of spending little and often to avoid spiralling costs further down the line.
If you have a wet timing belt, my advice would be to get regular inspections at a garage that’s familiar with them, replace the belt at the first sign of deterioration, and keep that engine oil as clean as possible. And only ever use the exact type of oil that the manufacturer recommends.
It’s hard to imagine what the engineers were thinking when they introduced this feature, given how unpopular it has become. But, it just goes to show that the rigorous testing cars undergo cannot catch every type of fault.
Finally, a word of warning to owners of cars with the standard timing belts. You may not have the same issues to contend with as a wet belt, but you still don’t want to get complacent, because they can and do fail. So, stick to the change interval given by the manufacturer…”
