How to Paint Your Engine Block

By May 21, 2014Engine
Painting Your Engine Block

One of the best improvements you can make to spruce up a tired-looking engine compartment is painting your engine. No matter how good the car looks or sounds, a couple of coats of high-gloss red, orange, or blue paint really adds that final wow factor when you pop open the hood. As a bonus, a clean engine with all the sludge and grease removed helps it run a little cooler. Normally, you can do this without removing the engine from the car, unless you want it to be factory-perfect of course.

TOOLS

1. Remove Engine Accessories

If you’re going to leave the engine in the engine bay, you need to get as much access to the block, heads, and intake as possible. Start by disconnecting the positive battery cable as a basic precaution. You’ll need to remove the air conditioning compressor (if so equipped), power steering pump, alternator, and smog pump (if so equipped).

2. Label and Disconnect Wires and Hoses

For the nicest looking job possible, you need to disconnect everything (or as much as you can) and move it out of the way. This means spark plug wires, coil wires, fuel lines, radiator and heater hoses, vacuum lines, etc. Label them using the masking tape, bundle them together as much as possible, and put the connection ends of the wires into a plastic bag and either tape or zip tie them out of the way.

3. Mask Off

In addition to spraying paint, you’ll first be using a water hose so you want certain areas to stay dry and protected from overspray. Remove the spark plugs and tape off the plug openings. Place tape over any electrical connectors such as temperature sensors. If you’re leaving the distributor/coil packs attached, mask and bag them to keep them protected. Bag and tape the water pump inlet and outlet. Cover up fuse boxes. Remove the PCV valve and tape over the opening if your car has one. Bag the harmonic balancer. If you have a carbureted engine, remove the air cleaner and stick paper towels on top, then cover it with a plastic bag and tape around the base to keep it secure.

4. Clean and Degrease Thoroughly

Spray the engine degreaser all over the engine compartment liberally. LIBERALLY. For a really greasy, nasty engine, you may have to do this step twice. Use a wire brush on areas with heavy build up to let the degreaser penetrate more effectively. Don’t forget the fenders and bulkhead. Let it sit for 15-30 minutes to do its job completely. Get rid of any flaking paint or rust because the new paint won’t stick to these areas for long. After the soaking period, hose it down. Like we mentioned above, high pressure water works best, but not everyone has a pressure washer handy, so a pistol grip hose nozzle works great too.

With all the degreaser washed off, wet a rag with paint thinner and wipe down the whole engine. Pour some thinner into a container and use the paint brush over the whole engine compartment. The paint won’t stick to the residue the degreaser leaves behind.

5. Paint

There are a variety of high temperature engine paints available and you can choose to match the paint to your year and engine or use a color to complement your custom paint job. Both Duplicolor and VHT have charts of OEM engine colors plus other custom colors they carry.

Using smooth and even strokes, releasing the nozzle button on the spray can after you’ve gone past the engine, apply the paint. You will probably want at least two thin coats. Allow each coat to dry to a tack before applying the next coat, otherwise you could end up with runs. Spray down as far as you can and then get the bottom of the block from underneath your car.

Follow up with a paint brush to get the areas you missed or couldn’t reach with your spray can. The level of detail in your paint job makes a huge difference in the end when you get everything put back together.

Wait until the paint is completely dry before re-installing all the components and at least 8 hours before starting your engine.

Additional Tips
  • In some areas just hosing the gunk and degreaser off your engine is illegal. You may need to use a catch basin and dispose of the waste properly.
  • Most store bought engine enamels don’t require a primer and if you are thorough with your preparation then you’ll get long-lasting results. But you can also opt for an entire coating system which includes an engine primer and can even include a clear and other prepping sprays.
  • Don’t forget to get your hoses and wires looking just as new as your engine with cleaning oils and lubricants especially made for rubber.

Photo credit: Robert Couse-Baker

Join the discussion 1,483 Comments