My 85 year old parents have just moved back to the city from a very rural area with Dad's perfect condition,All maintenance on time with 62 thousand miles. 02 Mercuy Marquee, Until i opend the hood. The engine compartment is covered with white rock and sand dust thick! I would like to take the car to the car wash to clean under the hood is there somthing to do or not do. Dont want to mess with computer an stuff.
I've washed under the hood of my 99 F 150 a few times without any problems. I'd say just don't force a pressure stream on any electrical components and you should be fine....
be particularly careful around the coils. If you force water into the holes they will short and potentially damage the coils. If you notice it running rough after you do wash it, you will need to remove each coil and blow the water out of each plug well with compressed air.
Yea, the local clean up shops paid a good portion of my income for a while before they figured it out.