Workshop Activities

With the exception of regular oil changes, most modern engines are becoming almost maintenance free. One of the refinements fitted to achieve reduced servicing requirements is the hydraulic tappet. Through hydraulics, the need to adjust valve clearances has been eliminated.

The camshaft which operates the valves acts on a hydraulic plunger. With the camshaft off the hydraulic plunger oil can flow into the hydraulic tappet. When the camshaft starts to move the tappet down, the oil's passage way is closed. Oil in the plunger is now compressed by the cam which in turn opens the inlet or exhaust valve.

The oil's passage way into each hydraulic tappet is very small. Over a period of time the oil's passage ways will become clogged and the tappet efficiency will falter.

Remedies

A good quality motor oil, of the recommended viscosity, is essential. A consistent viscosity (oil thickness) over the engine temperature operating range is crucial for consistent engine operation performance. Such qualities are best found with the more expensive oil product ranges.

When performing an oil change the use of an engine flush will help to remove lacquer build up on the tappet oil's passage ways.

Manufactures may quote ever increased intervals between oil changes, but ask any motor technician the period their vehicles are run between oil changes, few will stretch oils over 10,000 miles.

A partnership established 1983

Telephone 01443 231135

Pratt's Garage, Unit 5 Cambrian Ind. Est. Coed Cae Lane, Pontyclun, CF72 9EW

The web site sets out typical work undertaken and some technical topics which may interest you.