What oil and filter for my Triumph?
QMy Triumph Vitesse is used regularly over the summer. When I start it after it’s been standing for a few days, the engine knocks alarmingly for a few seconds. I’ve been told it’s oil-related. I’m using ‘classic’ 20w50 oil – but I’ve seen modern synthetic oils recommended on web forums. What should I be using? Neil Ballard, Normanby
AThe start-up rattle you describe is common on Triumph’s six-cylinder engines and sometimes its four-cylinder engines, too. It’s caused by the oil draining back from the filter to the sump while standing. As a result, there’s a slight delay between the engine starting and the oil pump refilling the filter and building up pressure. The crank bearings knock until they’re sufficiently lubricated by the pressurised supply.
The original Triumph oil filter is a disposable paper element housed in a steel bowl on the rear left-hand side of the engine. Triumph specialists sell an adapter that attaches to the block and allows a spin-on canister type filter to be fitted. The filter is angled downwards to prevent the oil draining out when it’s standing. The filter to use is a Unipart GFE227 or a good quality equivalent. If space is tight between the chassis and the filter – such as it is on the TR6 – use a Unipart GFE180 instead. It’s a shorter version of the same filter.
The four-cylinder engines fitted to the Spitfire, MG Midget 1500, Herald and others can suffer the same problem, but for a slightly different reason. The four-cylinder takes a spinon filter as standard, but it’s mounted almost upside down. It’s therefore important that the filter incorporates a non-return valve to stop the oil draining out when it’s standing. The correct filter is a Unipart GFE150. If you buy an alternative brand, have a look through the outer circle of drain holes. The valve’s rubber flap should be visible. Note that the quality and effectiveness of these valves can be variable – and they’re not immune to failure.
Classic 20w50 oil is what you should be using. It’s exactly what Triumph specified for use in temperate climates like the UK. There’s absolutely no advantage to using an expensive modern synthetic oil – a ‘classic’ oil is far better suited to older engine designs.
The only reason to use anything other than 20w50 is when running in a rebuilt engine. In this case, use a classic SAE30 monograde for the first 250 miles to aid the running in process – then drain it, change the filter and refill with 20w50.
Always take the car for a drive and get the engine up to full operating temperature before changing the oil. This will aid draining and ensure that dirt and combustion by-products are suspended in the oil and come out with it.