How To Pressure Wash Your Car’s Engine Bay

So you’ve just pressure washed your car, dried it and waxed it and now it looks like it just came out of the showroom. The interior has been hoovered, cleaned, interior windows are gleaming, upholstery looks amazing, and it smells beautiful. What about the engine bay?

Over time, dirt, dust, oil and grease will build up onto the engine and engine mountings, it’s inevitable. It needs cleaning but how do you clean it? How about the pressure washer?

Is It Safe To Wash Your Car’s Engine With A Pressure Washer?

We checked with a few car manuals and out of the 10 we read, 6 never mentioned cleaning the engine. But 4 said if you live in an area where snow and ice are common, it is advisable to wash your engine in the Spring to remove any salt residue as it can cause electrical and/or mechanical problems. So it’s OK to wash the engine then, but is it OK to wash the engine using a pressure washer?

Well, it is as long as you are careful, take the correct precautions and don’t get trigger happy with the spray gun. Also, the age of the car will affect whether it’s safe to use a pressure washer or not. Since the 1990’s cars have been fitted with water sealed cables, older models will probably not take water so well and should probably not be pressure washed.

How To Protect Electrical Components From Water Damage

You’re not going to be spraying pressurised water for too long, but that doesn’t mean you can’t do any damage. So you need to protect delicate components from too much water, remember most engines get wet in rainstorms and when driven through puddles, and they’re OK. So as long as you cover up the delicate bits and don’t use too great a pressure, and don’t take too long about it, the engine will be fine.

Cover all alarm systems, distributor, alternator, and other electrical connections with plastic and tape them to keep any water out. Or if it’s a short clean you could use an old towel or carpet etc. Follow our easy step by step guide to successfully clean your car’s engine without damage.

How To Clean Your Car’s Engine With A Pressure Washer In 9 Easy Steps

How to wash a car with a pressure washer

These steps are the best way we’ve found for getting your engine and engine bay clean in a short amount of time and without causing any damage to your car.

  1. Warm the engine
    It doesn’t want to be hot, just not cold, you need to be able to touch it without burning yourself, but it needs to be warm to help remove the grease.
  2. Protect delicate parts
    Using plastic and tape, cover all exposed electrics like the distributor, the alternator, coil, alarm, battery terminals, and any electrical connectors, and make sure they are fully sealed.
  3. Use the correct degreaser
    Make certain it’s safe for use on your engine (consult your dealership if in doubt), spray the cleaner over the whole engine. Ensure you cover everywhere.
  4. Allow to work
    Leave the cleaner on the engine for 5 to 10 minutes (or follow the instructions on the bottle).
  5. Get scrubbing
    Use a scrubbing brush to make sure the cleaner has got into all the nooks and crannies (a toothbrush is ideal for this).
  6. Pressure wash
    Making sure you’re using low-pressure, and the white nozzle, and that you’re at least 3 to 4 feet away from the engine, spray from above and move back if it feels too powerful. And forward slightly to increase the pressure. Work from the back to the front of the engine and remember to not concentrate on any one area.
  7. Dry the engine
    Use a cloth to dry the engine, once dry, remove the plastic and the tape.
  8. Spray the hoses and cables
    Using a rubber and vinyl protector, spray the hoses and electrical cables to protect them from damp and damage.
  9. Start the engine
    Once you’ve completed all of the above steps, start up your engine and admire the gleaming shine of a thoroughly clean, brand new, looking engine.

Safety Tips For Cleaning An Engine Using A Pressure Washer

Apart from ensuring the safety of your engine and electrical components, you need to be mindful of your own safety too. Here are a few tips for keeping you safe whilst cleaning your engine with a pressure washer.

  • Wear PPE
    Whenever you use a pressure washer, even an electrical pressure washer, the water pressure can cause serious injury. Always be sure to wear goggles, gloves, boots or closed in shoes, keep your arms and legs covered and consider wearing a face mask.
  • Be aware of any obstacles
    Trip hazards are common in gardens, and on drives. Move as many hazards as you can, pot plants, children’s toys, garden furniture, cables, hoses, even tools can cause you to trip and hurt yourself especially if you are concentrating on operating your pressure washer.
  • Keep the pressure low
    Only ever use low-pressure when using a pressure washer in a confined space like an engine bay. Be aware of spray back, due to the force that the water is subject too even rebound spray can cause you harm.
  • Look out for children
    Kids love to be with their dad, especially if he’s doing something fun like pressure washing. The high-pressure water is capable of removing adult skin, imagine how much worse that could be on children’s skin.
  • Know where your pets are
    Cats and dogs often hang around the garden when the people are outside, be sure not to blast a pet as the vet bills could be astronomical.
  • Take care around rust
    Rusted bolts can sheer off under high-pressure take care and check all bolts, screws and any other loose or potential loose materials before you start pressure washing.
  • Dispose of rubbish responsibly
    After you’ve removed the plastic that you covered the electrical components up with, be sure to dispose of them correctly.

SEE ALSO: How To Wash A Car With A Pressure Washer (& avoid common mistakes)

Frequently Asked Questions

Can I pressure wash my engine bay?

You can pressure wash your engine bay as long as your car was made after 1990. After 1990 all cars were fitted with water-resistant electrical cables.

Is it safe to spray your engine with water?

It is safe to spray your engine with water, as long as you own a fairly modern car and you cover the alternator, distributor etc.

Can you use wd40 to clean engine bay?

You can use WD 40 to clean an engine bay, but a degreaser is more effective.

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