LCV Wet Belts

Wet Belts in LCVs and Vans

Wet belts, also referred to as wet timing belts or BIO (belt-in-oil) timing belts, have become more common in a variety of vans and light commercial vehicles from some leading manufacturers. Here we discuss what wet belts are, their pros and cons, and the importance of regular maintenance to avoid what can be some costly problems.

What are Wet Belts?

The timing belt (or chain) is traditionally mounted outside the engine, and consists of a toothed belt connected to the crankshaft and camshaft to synchronises their rotation, to ensure the engine's valves open and close at the correct time with the pistons. By contrast, the wet timing belt is housed within the engine and is bathed in oil.

The Advantages of Wet Belts

Under pressure to reduce emissions, wet belts were seen by some manufacturers as an efficient and economic response. Wet belts are designed to reduce friction (friction loss is said to be up to 30% lower than dry systems) and wear through lubrication by oil, and thereby improve fuel economy, less fuel used meaning lower CO2 emissions. The design is intended to prolong the life of the belt, reduce noise, vibration and heat, and aid with compact engine design.

The Disadvantages of Wet Belts

Despite these advantages, it is widely commented that wet belts are, in real life operation, prone to a number of issues. They are highly dependent for successful function on adherence to the manufacturer's maintenance schedule (indeed, some garages recommend replacement ahead of schedule) and use of the recommended type of oil.

Impurities in the oil can cause belt wear and inadequate oil levels or use of improper oil could also cause problems. Fragments in the oil caused by the degradation of the belt can then cause blockages, oil starvation, and in the worst case scenario, severe engine damage.

Maintenance and replacement of wet belts are both more time-consuming and costly than dry belts, due to the need to drain the oil and dissasemble the housing, carry out the required work, then reassemble.

Which Vans and LCVs use Wet Belts?

Some of the biggest manufacturers have produced common van engines using wet belts, including Ford and the marques under the Stellantis banner, i.e. Peugeot, Citroen and Vauxhall.

Examples of these engines are Fords's 1.0L EcoBoost petrol and 2.0L EcoBlue diesel engines, found in the likes of the Ford Transit and Transit Custom. Stellantis vans equipped with 1.2L 3-cylinder petrol engines, such as the Peugeot Partner, also use wet belts.

What are Signs of Wet Belt Problems?

The very characteristics of the wet belt system that suppress noise, which might be a giveaway of an issue, make it harder to detect problems. Writing for Commercial Vehicle Magazine, Lou McCaskill of GT Automotive Parts notes that "there are no clear signs that a wet belt may be failing".  Regular inspection and maintenance therefore becomes critical.

Signs that may indicate failure nonetheless may include any unusal noises, misfires, smoke, loss of power, low oil pressure and the illumination of the engine management light (EML). When checking or changing oil, rubber debris contamination in the oil may be a sign that the wet belt is deteriorating and releasing matter into the oil. An oil filter inspection during routine servicing can therefore help identify signs of early wet belt wear.

How Servicing Can Help Prevent Wet Belt Problems

Wet belt failure can lead to massive and extremely expensive engine damage, including damage to valves, pistons and oil pump. At the extreme, the engine may become completely unusable and require total replacement.

To avoid such problems, for vans and LCVs, indeed all vehicles, fitted with wet belts, it is paramount to carry out servicing according to at least the manufacturer's recommended service intervals, in combination with regular inspection. This can help avoid serious failure requiring costly repairs.

If at all unsure, it is best to book an inspection or service with the van and LCV specialists at Dowleys. The workshop at Dowleys is staffed by experienced mechanics with extensive experience working on a wide range of vehicles. Our garage is equipped with the latest diagnostic tools to make sure your vehicle is maintained to the highest standards.

Fleet Van and LCV Servicing

Our workshop has ample capacity to carry out servicing of vans and LCVs for fleet operators. So if your company relies on having multiple vehicles on the road, we can help mitigate the risk of lost business due to out-of-action vans, with all aspects of van and LCV servicing and maintenance, including wet belt servicing. Contact us today to discuss your fleet servicing requirements.