Engine cleaner

[SquareOne]

I'll typically spray a degreaser/laundry detergent mix as a pre-soak on a cool engine. 1:1 water/degreaser mix combined with a capful of cheap laundry detergent (just helps the solution stay where you spray it) and I'll let it sit for about 7-10min depending on ambient air temp. You'll see any road grime or oil running off as you wait.

If your engine isn't totally oil bathed, this presoak will get most of it off with a little elbow grease and water pressure from your hose.

(Rawze, look away lol) - Now, if you're engine is filthy with a good amount of road grime combined with a handful of neglected leaks, there's nothing that will clean better than heat/pressure. Let me be clear...PRESSURE WASHING IS NOT RECOMMENDED ON THESE ENGINES, but with proper precaution, presoak, heat and the minimal pressure washer setting (lowest regulator and lower engine idle), I'd challenge anyone to get a better clean.

***However, you MUST TAKE PROPER PRECAUTION as to stay away from electronic components. Just use common sense. Don't hammer any sensors, wiring and ECM. High-pressure wands used improperly will certainly cause loads of issues due to moisture intrusion.

I now have over 750k on my engine and have been using this process successfully for the last 500k miles. My engine fortunately does not leak, but for a truck that goes off-road onto a farm daily, it has a very clean engine/bay area. It's a pleasure to maintain as well since you can crawl around it without being filthy. Also much easier to spot an issue when everything is clean.