Td5 Technical - Oil Filtration & Pump
The oil pump in the Td5 is mounted at the front of the crankcase stiffening plate, and has a short chain drive from the crankshaft. It picks oil up from the sump and feeds via galleries cast in the stiffening ladder, to the cylinder block oilways. The oil jets that provide piston cooling and small end lubrication use integral pressure valves to close them off when the oil pressure falls below a set figure at low engine speeds.
In addition to a conventional full-flow paper element primary filter (canister filter), the Td5 also utlilises a secondary centrifugal filter.
Although the centrifugal type of filter is well known in marine engine applications, the Td5 is the first time it has been scaled down for use in a passenger vehicle application. The filter is mounted separately from the canister filter, and the filter element is spun up to around 15,000 rpm by twin oil jets leaving the filter. Particles between 3 and 15 microns are impacted onto the inner wall of the canister, removing them from the oil.
10% of the engine oil flow is filtered by the centrifuge, with the remaining 90% of the flow passing through the full-flow filter.
The centrifugal filter is replaced every 12,000 miles (20,000 km), and this device increases the oil change intervals to 12,000 miles (20,000 km) and the canister filter now lasts for 36,000 miles (60,000 km).
The housing between the two oil filters contains an oil to coolant oil cooler, instead of a Tdi type oil to air cooler. This is thermostatically controlled, altering the oil flow through the filter depending on the engine oil temperature to speed up engine warm-up.
Back to Td5 KB