How do you clean a car’s engine?

By Roger Houghton

The most important point to remember is that water is the enemy of electrical systems and there are plenty of the latter under an engine’s bonnet. So, what you should do first is to cover electrical items such as the ignition distributor and coil (in older model cars) and computer control boxes with plastic bags tied with insulation tape.

It is inadvisable to clean your engine with a pressure washer, as this can get water into places where water shouldn’t go! Rather use a couple of different-sized paint brushes – with stiff bristles – and either a commercially available engine cleaner or soap powder (such as Surf) mixed with warm water. DO NOT USE PETROL as it is a major fire hazard:

Wash and scrub the various parts and under bonnet surfaces and then wash off the dirt with a hosepipe without too much water pressure. Where grease or other deposits prove stubborn to remove then it is best to spray it with engine cleaner, Clean Green or dishwashing liquid and leave it to stand for a while before trying again to remove the deposit.

Once you are happy you have removed most of the dirt, then remove the plastic bags and allow the engine to dry. Then it should only require some rubbing with a dry cloth and the application of polish if you are really keen.

Finally, it is time to fire up the engine and hope that water has not penetrated any of the electrical circuits!