The engine bay of my car is a greasy grimy mess, between years of mechanical fluid buildup and the fact that the previous owner apparently had it parked under a tree at some point, I've found dirt and pine needles on the top of the engine block and it looks like someone did not understand the core idea of why you use a funnel when adding engine oil.

However, my other vehicle is a Ford F150 with the notorious 5.4 Triton and one of the biggest no-no's with that engine is spraying any quantity of water under the hood because of the genius idiotic design of the spark plugs and their housing. Basically any water will just sit in the spark plug hole and potentially short out the ignition coils.

So with that in mind, I thought it would be a good idea to see if there are any potential troubles I should watch for before I go to cleaning up the years of accumulated grime on my engine. My dad always sprayed engine cleaner on his engines and power washed the bay about once a year with his vehicles without any issues, so obviously my Ford's woes aren't universal... But I'd rather be sure just the same.

 

There isn't any problem that I know of with the ignition system and water on these cars, I've used degreaser spray and a garden hose to clean my engine bay many times. I just like to avoid directly spraying electrical connections, the distributor, etc. If you take off the air cleaner, good idea to put a plastic bag or carb hat over the throttle body.

 

Hi there,
I would advise against the power washer. I get very good results with just a garden hose and various degreasers and detergents. Like Firebirdwade said, avoid directly spraying wiring connectors and the distributor (you can put a plastic shopping bag over it) and take a few rags to dry off the wires when you are done. If spots don't come clean the first time, hit 'em with degreaser again and scrub again.

The power washer blasts too much water everywhere, and will get water into something you don't want it to.

 

All sound advice.

I find one of those parts washing brushes helpful as well.

Even if you're using a garden hose, there's still the potential to get condensation under the distributor cap and other places depending on the temperature of the engine/water, etc. so be mindful of where you direct your stream.

Back before HEI it used to be an issue but I don't know how big a deal it is these days.

Water intrusion is still an issue with some of my imports that have the spark plugs buried in deep holes.

I blow off the excess water with straight extension but with the pressure regulator turned down.

 

I would cover your distributor and try not to keep the water pointed at it or the ignition coil or exposed electrical connections for very long. I've seen some super experienced detailers clean an engine and couldn't get it to start for hours and occasionally had to change ignition coils just to get the car started again. I've had good luck with degreaser and Purple Power cleaner and rags/paper towels in terms of getting off grease.

 

I cover the battery, alternator and remove the back piece of the TPI to cover the distributor with trash bags.

I use simple green and various sized brushes from a soft wheel brush to a tooth brush for nooks..

Do it when Engine is cold and let it soak a few minutes and then re spray and brush all the areas you can see..

Use a trickle of water to rinse.. even use a water bottle with a squirt bottle..

I use a shop vac to suck up pools of water around the intake, etc..

I clean the painted surfaces and touch up areas with Detail mist..

Blot dry with terry towels

Then I spray tire foam on hoses, black plastic, etc.. it cleans and shines after a couple hours..

Start it up, let it run a bit (there will be burn off)

I’ve never had a car not start on me!



I worked for a body shop/dealership from 18-24 and was a detailer..

That’s what we did anyway..

I still Detail cars but don’t do engines.. new cars have way too much electronics going on.. I’d do mine because I know what’s what..

 

Power washing will give you problems.. I’d advise against it.. best case your car will run rough for a day.. worst case you’ll be taking stuff apart drying stuff out..