Many vehicle owners wonder if washing an engine bay is a necessity due to the inherent risk involved. We have all heard the tales of damage caused by engine washing. The fact is that modern engines are made to be water resistant, weather-tight connectors, distributor-less ignitions and newer gasket technology, the water sensitive devices are well protected and will easily resist frequent washing; however, care should be taken when using a pressure washer or hose.
Steam or Dry Ice can both be used
I would recommend wearing a pair of latex gloves while working on the engine compartment. Road grime, tar, and grease are very difficult to remove from underneath your fingernails. Outside of the garage, your hands shouldn't look like you need lessons in personal grooming.
Permatex® Disposable Nitrile Gloves are made from a 100% synthetic rubber that provides superior resistance to a wide range of solvents and hazardous chemicals. Nitrile gloves are suitable for users with natural rubber latex sensitivity. They feature textured fingers that provide a secure grip on dirty parts and tools. These gloves are lightly powdered, which makes them easier to put on and take off. When superior chemical resistance is required, these disposable gloves provide mechanics with ideal heavy-duty hand protection. Excellent protection from greases, oil, diesel fuel, acids and many petroleum-based products
Disposal of Aqueous Solutions
One should never assume that aqueous solutions can be disposed of down the drain. Your local water treatment authority or publicly owned treatment works will have information on treatment and disposal of these cleaners. Adjustment of pH and dilution are usually required before disposal to a drain.
Do not use a solvent based product for engine compartment detailing as solvents have a low flash point and could start a flash fire in the engine, solvents also deteriorate and expands rubber, which may have a detrimental effect on belts and hoses.
Protection of Electrical Components
Avoid the [I cleaned the engine and now it won't start] scenario by covering electrical/electronic and various other parts prior to using any cleaning products, sprays or water. If you’re unsure either protect with a covering and /or use WD-40 water repellent
The most important electrical components are sealed to be ‘water resistant’ or splash proof to resist water ingress that is to say against low pressure, water splashing upwards from the road that is encountered in the course of daily driving conditions, despite their coverings they are not ‘waterproof’. Rain or water splashed up into the engine is at very low pressure, very different from a pressurised hose or steam
Allow the engine to cool down; cold water on a hot engine will cause thermal shock, which could cause the block to fracture. Allow the engine to run while you are using a water spray. Then leave it running for approx. five minutes after you are finished spraying. This allows any water that remains to evaporate with the heat of combustion
As long as you use common sense by avoiding a direct strong stream of water (or a pressure washer/steamer at close range) directly into these components, you will be fine.
· Alarm Housing
· Battery terminals (if not covered already)
· Induction kit cone (if you have one)
· Coil packs
· Electronic control units (ECU)
· GM Opti-Spark Distributor
· On-Board Diagnostics (OBD) port
· Air intake systems (exposed air filters) can be covered with plastic wrap and a rubber band
· Avoid getting water in the spark plug recesses or the dipstick opening (seal with foil)
1. This is not an exhaustive list, nor is it marque specific, if in doubt use a water repellent (WD-40) and exercise common sense
2. Use cling-film and then tin foil for the alternator, alarm housing etc. as the foil is easier to mould and has greater protection properties. I suggest you use a plastic bag for the induction kit and just wrap it tight over the end to stop any water ingress.
3. For the intercooler, the best way to cover is to get a flat sheet of cardboard and just cut it to size so it fits and covers the fins. Cardboard will normally protect the fins for the duration of the washing. It will get soaked so discard after the wash.
4. If you are uncertain of how to proceed on something not included here; talk with somebody who has marque /model /year specific knowledge.
Electronic Control Unit (ECU)
Disconnecting the battery will cause the radio pre-sets and the seat position memory to be lost (disconnect ground first then live terminal). Once the battery is re-connected (live first and then ground terminal) the engine control unit (ECU) will reset automatically; this is a good thing to do occasionally anyway.
Modern ECUs use a microprocessor which can process the inputs from the engine sensors in real time. An electronic control unit contains the hardware and software (firmware). The hardware consists of electronic components on a printed circuit board (PCB), ceramic substrate or a thin laminate substrate. The main component on this circuit board is a microcontroller chip (CPU). The software is stored in the microcontroller or other chips on the PCB, typically in EPROMs or flash memory so the CPU can be re-programmed by uploading updated code or replacing chips. This is also referred to as an (electronic) Engine Management System (EMS).
1. Do not open the hood while the wiper arms are in an up position; the result could be a cracked windshield
2. Work on a warm engine, if it’s hot; allow it to cool down (cold water on a hot engines casting may cause it to fracture)
3. Remove any excess debris, leaves and etc. from the hood, grille or air-vent openings
4. Spray electrical connectors with WD40 which repels moisture/water (avoid spraying on belts)
5. Use cling-film or Saran wrap elastic covers to cover any sensors, electrical black boxes, electrical devices that could cause an electrical short-circuit if subjected to water spray.
6. This will not guarantee that you won’t cause a problem when cleaning an engine bay but it will greatly reduce the risks.
7. An emphasis on a warm engine as (heat) reactivity will accelerate the strength of the cleaner and it can cause much more harm than good.
8. Start and run the engine to get it warm, not hot, this will enable the de-greaser to work more efficiently on a warm surface.
9. Unless you have leaking fluids, you shouldn't need an aggressive degreaser or a high-pressure washer/steamer.
10. Apply a de-greaser or an all-purpose cleaner (P21S®® Total Auto Wash or Optimum Power Clean All Purpose Cleaner Degreaser) or a solvent free, water based cleaner (Wurth Engine Cleaner and Degreaser or Simple Green® Aircraft & Precision Cleaner, for cleaning engines, aircraft, vehicles, and equipment. most of these engines don't really need the use of harsh degreasers. This product is safe for painted surfaces, gel coat, aluminium, carbon fibre and other composite materials) by lightly spraying the lower parts of the engine first and then working upwards.
11. Enable the cleaner to work by allowing remain in place time (but do not allow to completely dry) or to remain on painted surfaces, and be sure to dilute with water before drying with a cloth.
12. For heavily soiled areas agitate with a nylon engine cleaning brush and an undiluted cleaner or degreaser (Wurth Engine Cleaner and Degreaser or Optimum Power Clean All Purpose Cleaner Degreaser)
13. When the grease and grime is dissolved and you're ready to remove it, spray with a light (garden type) fan-spray pattern pressure water a hose and then agitate with a Mini E-Z Detail Brush.
14. To shine aluminium engine block/parts use # 0000 synthetic bronze wool and a metal polish, English Custom Polishing – ECP
15. Use the blower side of a vacuum (avoid area that may be sensitive to a forced air flow) or allow the engine compartment to air dry and then thoroughly wipe down all accessible surfaces
16. Make sure you have removed the clingfilm, aluminium foil or saran wrap and all other products used to cover or protect sensitive parts from the engine bay. Start the engine and let is run for at least 1 – 2 minutes to help dry some of the water. Be careful touching the vehicle after because it can get hot fast.
17. Then finish drying anything that may need it.
18. When everything is dry apply a vinyl/rubber protection to hoses, shields, and wires, and wipe engine parts with Autoglym Vinyl & Rubber Care or 303™ Aerospace Protectant
19. Clean hard plastic and protect with 1z Plastik Reiniger
20. Wipe off any excess with a clean cloth and apply a wipe on, walk away Clear Sealant (Zaino Clear Seal Z-CS) or a spray wax protection to all painted surfaces.
21. Remove all component coverings that you’ve applied
22. Turn on the engine and allow it to run for about five minutes to heat up; this should dry any remaining water
Cliff Notes Version
1. Warm up the engine
2. Cover water sensitive components
3. Apply a mild degreaser and agitate
4. Rinse away residue
5. Remove any applied component protection (cling film, foil, etc.)
6. Apply protection to rubber/vinyl parts
7. Start and allow engine to warm up and dry engine bay
Cast Aluminium surfaces
The best methods for Concours cleaning of cast aluminium is by bead blasting, but if you just need to clean use an acidic cleaner. Do not use a strong alkali as it will cause carbon spots that are very difficult, if not impossible to remove.
· Thoroughly degrease the surfaces using Optimum Power Clean ™ and then rinse with clean water
· Clean surfaces with P21S Polishing Soap or Total Auto Wash
· Using a brass wire brush and Optimum Metal Polish scrub the aluminium surfaces
· Thoroughly rinse with clean water and then dry
· Use a polymer clear coating (Z-8 Grand Finale™ Spray Seal)
Modern engines do not require a harsh degreaser if you want to safely degrease your vehicles engine bay, Optimum Power Clean or Wurth Citrus Degreaser are both excellent choices. An environmentally safe product that can also clean your paint, wheels, tires, engine bay, wheel wells, trim and etc. The strong cleaning agents break down bug smear, road grime, brake dust, dirt, etc. Optimum Power Clean is also a great value because you can dilute it 3:1 with distilled water or use it full strength.
1. Apply a vinyl dressing to hoses etc. (no diethyl silicone fluid based dressings (DS) should be applied in the engine compartment. Use only water based Polydimethylsiloxane (PDS) dressings and do not directly spray on to engine parts, spray a cloth and wipe contains no Clean Air Act Hazardous Air Pollutants (HAP) nor is it an RCRA hazardous waste in and of itself when disposed of.
2. Aluminium -remove any surface oil/grease etc., polish the part, spray on a coat of VHT Flameproof clear coat, and allow to dry- Caswell Inc.
Quick Engine Cleaning
· Mix up some ONR (QD strength i.e. 8 oz. per gallon) in a spray bottle or a garden pest pump spray
· You’ll need a few small brushes and old terry cloth towels.
· Use a pre-cleaner solution, 10:1 distilled hot water/ P21S® Total Auto Wash
· Spray the engine and let the solution remain in place for a few minutes.
· Agitate with brushes to loosen road dirt, oil, and grime as needed.
· Re-spray with ONR solution, then wipe dry.
· Start engine and let it run until completely dry.
· Use Iz einszett Gummipflege or CD-2 for all hoses etc.
Note - Do not direct spray to any sensitive electrical components (see “Protection of Electrical Components for details)
Spray on Optimums Heavy Duty Degreaser and allow to dwell and then with a water hose or power washer hose radiator to remove road dirt and grime. To clean off insects and bugs simply spray on Iz einszett Anti-Insekt, allow to work for 3 minutes then hose off to remove debris. Iz einszett Anti-Insekt contains special cleaners which loosen insects and grime from paintwork, chrome, glass, rubber, and plastic gently and safely without harsh chemical solvents. The formula does not contain enzymes, which can irritate skin, is biodegradable, formalin-free, and environmentally safe. For stubborn carcasses use a soft radiator brush that won't damage the fins