Cleaning the Engine

The most important thing to remember is to never work on a hot engine – always let it cool down before you clean it.


There are many benefits to keeping your vehicle’s engine clean, although they are often overlooked. By ensuring the engine is free of dirt, you can extend the life of your engine and the rest of your car. As a bonus, the vehicle will be safer with less chance of something going wrong.

The most important thing to remember is to never work on a hot engine – always let it cool down before you clean it.

After that you need to ensure that necessary components are covered up – tin foil will usually do to protect the parts of the engine you aren’t working on, otherwise, you can cause severe damage to the engine. Remember to never spray a high-pressure stream of water into the engine bay, this can cause expensive damage!

The engine is exceptionally delicate, and we suggest you follow this guide carefully. The process is very technical. Procedures need to be followed precisely, to ensure safety and to make sure you do not cause any damage to essential components.


This week we were working on a Mazda 3 engine, powered by a 2.5-liter naturally aspirated I-4 with 186 hp and 186 lb-ft of torque. All of this under the hood makes for a ton of fun when driving the car. Unfortunately, the engine bay was filthy. After we gave the engine a full clean everything was in perfect working order for the best performance possible.

It is crucial to wait until the engine is cool before you start work. Ensure the engine is cold enough to touch. Do not start wetting the exhaust manifolds and piping when they are red hot. A good rule to follow is to wait at least 30 – 45 minutes after you have stopped driving to allow your engine to get to room temperature.

Once you are happy that everything has cooled, you will need to ensure that you cover any sensitive fuse panels, electronics and air intakes with a plastic bag, providing a good seal, so no water gets in.

The next step is to take your vacuum cleaner and remove the debris that accumulates in the crevices of the engine area to remove any loose dirt and dust. Be sure to do this before you bring any water into the equation. Following this, you want to do a quick pre-rinse using a light spray of water, this will help to remove any surface dust easily.

Then, take your chosen product, we use IGL Multipurpose Cleaner and a selection of soft detailing brushes. Top tip: use both short and long-handled brushes. The longer handle allows us to reach tighter places within the engine compartment easily.

After you have rinsed everything, spray on a decent amount of your chosen multi-purpose cleaner. Be careful not to saturate electrical connections, even though they are mostly sealed by the manufacturer these days, it’s best not to take the chance.

Wait another couple of minutes for the multipurpose cleaner to work on the tough dirt and grime – then start to work the areas with your detailing brushes, starting with the least dirty parts first. After everything has been scrubbed, you can do a light rinse again with your hose, not too much water, just enough to rinse the areas clean.

When you have finished, you need to use compressed air to ensure the engine area is as dry as possible. Then follow up with some good quality drying towels. Finally, we always like to apply a dressing with something like IGL Dash to the plastic components to make it look even better than before!