Car Clinic: Dry-Cleaning your Engine

Car Clinic: Dry-Cleaning your Engine


I notice in the car clinic of July 30 THAT Dimitri discourages washing the engine using high pressure water jets. While I find that educational how are we supposed to wash our engines?



Tsholo, Dimitri didn’t elaborate on that, so all I can do is suggest a method that I believe will be safe on all cars. It avoids ever spraying water over the engine, not even from a squirt can.

Some people will regard this as overly cautious, but I’d rather be safe than sorry. Sure, you can put cling plastic around sensitive areas beforehand, but what exactly constitutes a sensitive area? And how watertight is cling wrap, really, if a stream of water hits it from the wrong direction?

The engine can be slightly warm, but not hot. Start by using a stiff brush to work a small amount of degreaser into any metal parts on which there is a build-up of grease or oil. Power paraffin (“Voco”) works well for me as a degreaser, but there are other non-aggressive cleaners. Then wipe the area clean with a rag. Repeat if necessary. Now move to the metal parts showing the familiar oily residue with a covering of road dust. Such superficial dirt can be wiped off with a rag wetted with degreaser. Next, turn to the plastic and rubber parts.

Here I suggest you use a soft-bristled brush to spread a rubber and plastic cleaner/conditioner sparingly over all surfaces. A little goes a long way if you use a brush rather than spraying it on. I’ve had excellent results from Autoglym’s Vinyl and Rubber Care, but there are other products on the market. Let it penetrate for, say, half an hour, then wipe off any dirt with a clean rag.

In this way you not only clean these parts, but also prolong the life of plastics and especially rubber components. Cleaning the padded, sound-damping liner found on the underside of the bonnet and on the firewall of some cars, without producing a cascade of rinse water, presents a problem. The safest will be to first vacuum it thoroughly and then go over it with a sponge soaked in upholstery cleaner, followed by a drying rag.

Needless to say, one cannot realistically expect a commercial carwash to take the care outlined above. But then I’ve never quite understood why owners would ask a carwash to clean their engines. Cleaning an engine is the ideal opportunity to get to know your car: then you can inspect rubber hoses, boots and ducts for hardening and cracking, and detect emerging problems.

Finally, I think one should maintain a sense of perspective about engine cleaning. One would like to have a fairly clean engine (so that fresh oil leaks can be spotted easily, if for no other reason), and certainly one would wish to preserve and protect polymers as far as possible. But we are not going to perform open-heart surgery in the engine bay. The odd molecule of oil poses no threat. The odd drop of water does.

*For all your motoring queries, please contact Gerrit Burger: