21 Jun 2024
The voice of the independent garage sector

A month in the life of a vehicle technician

There is a saying that if you stand still long enough the entire world will pass by. I was in my 16th year when Vauxhall as it was then introduced the slant belt-driven 1.8 litre, 2.0 litre and 2.3 litre engines. I recall thinking “what a silly idea.”  
Like most modern technology, failure was usually down to a lack of maintenance, repair or product knowledge. Failures were usually caused by oil leaks from the cam cover.

Over the edge
Some years ago, in discussion with an OEM belt manufacturer, I questioned how warranty claims were handled with regards to breakage. It was explained that the belts were produced in a very wide strip, before cutting to the individual correct width. A sacrificial belt from each batch would be evaluated for manufacturing flaws. Failures therefore were certainly caused by incorrect fitment or overtightening. Belts often had a special coating on the teeth to assist in bedding in and friction reduction. This could easily be damaged forcing belts over the edge of sharp sprockets; Something I have been guilty of in the past.
Engines now have vernier sprocket adjustment or keyless sprockets with stretch bolts, making belt fitment much easier. Being trained as a professional engine builder means that for me using the correct locking tools comes as second nature, ensuring not only accurate timing but also correct tensioning.
In the past, engine failure due to oil starvation would often lead to a snapped timing belt, so let us explore the current phenomenon of belt failure causing oil starvation and engine failure.

Unbelievable as it may seem, wet belts, otherwise known as belt-in-oil (BIO), were first introduced in the 1970s.  The first European automotive application was in in 2008, within the 1.8 Ford diesel, and VAG EA211/EA288 engines. The subject of my story this month is the Ford Eco boost 1.0. These were introduced like most, if not all automotive innovations to reduce emissions, increase power and reduce noise and weight. On a more technical note, with the introduction of small 3-cylinder engines BIO belts absorb crankshaft harmonics, (NVH), while reducing friction up to 30%.
With service intervals of 150,000 miles or 10 years, it is another nail in the coffin of the auto repair shop, or is it? Sales of wet belt kits are actually one of the fastest growth products in the aftermarket! Why? Because they are failing prematurely, in my case at 54,000 miles.

Good sense
A customer booked in a Ford Focus Eco boost 1.0 2016 with 54,000 miles and full-service history mostly with Ford dealerships, due to low oil pressure. The owner, a lady, had the good sense to respond promptly and so avoided total engine failure. I was not personally involved in the initial assessment or most of the rectification. With the cam cover removed it became obvious total belt failure was imminent. Please refer to Fig.1 and Fig.2.
We faced two main obstacles. First, we did not have the special tools required, and second our customer could not afford the £1,500 estimated cost for repairs. So, we purchased the vehicle for £1,500.
As fate would have it, a good friend of mine needed a decent car and had a budget of £5,000.
We sold the car on at cost value, plus repairs valued at the above estimate. Thus, the garage benefit was in the repair. We ordered the tool kit valued at approximately £1,000 having to rent it at £80 per day due to a back order in manufacturing and delivery.
Upon receipt of the tool kit in two parts, the locking kit, and the torque multiplier we proceeded to dismantle the engine including the sump. This is where I came in. The oil pump, also wet belt driven, was totally blocked with fibre fragments from the failed belt. I removed a big end cap to examine the crankshaft journal and bearing, remarkably with no excessive wear or discolouration due to friction whatsoever. Please refer to Fig.3 and Fig.4.
The reassembly went smoothly after we obtained a full belt kit with tensioner, pulleys, crankshaft bolt and crinkle washer.
If you recall my previous comments about key less sprockets and stretch bolts the crankshaft bolt is set at 60nm plus 5x 90 degrees. This must never be reused as indeed should any stretch bolt.

Good running order
The vehicle was duly restored to good running order, fully serviced with brakes, two tyres, tracking, wipers etc, and a personal Frank Massey valet, all at a cost of £3,000, valued online at £6,500.
Onto the most important aspect of this story, which as always is; “Why?”  Incorrect oil specification? I do have knowledge of dealerships buying oil in bulk to cut service costs, a practice also undertaken by many independents, so there’s that. Could it be the result of oil flush additives being applied? I have been advised that these can cause belt deterioration. Might this be the answer? On this occasion, I do not have a definitive conclusion, which as a diagnostic engineer, concerns me. Coupled with cars from several French marques like Peugeot and Citroen also suffering premature belt failure, I think need to learn more.