I know, I know. - Scary thought. I used to 'gently' do this to my other cars. - I'm a neat freak. In my part of Canada a bit of salt and sand can get up there from the the winter. Curious, has anyone tried this? With this car I just go in there with a moist rag.

Dave,

I just use Simple Green Max 50/50 with water in a garden sprayer. This allows you to get into small areas to apply. Let it set a minute or two, agitate with a part washing brush and rinse with a normal pressure water hose. No end on the hose, just an open hose and rinse from the top down.

Dry most of the water off with compressed air, crank the engine to dry the rest, let the engine cool and spray on CD2 engine detailer. When the CD2 is mostly dry, wipe with a lintless towel (I use my old microfiber) and then drive for 10 miles or so to set the polymers in the CD2 coating. Seems to do a nice job.

Here is mine after a cleanup:

Until Feb. 10, 2009:

I just let our engine bay get grubby, except to wipe down components with a rag as needed: say wiping down the brake fluid cap prior to opening, or a periodic wipe down of the battery top face. My logic: a clean engine bay is purely cosmetic. And you do run some risk of shorting something out. Also, anything you spray on and then hose off will end up in nearby streams.

First off, those are impressive pictures. Not sure if that is the CD2, but that is extremely sharp looking engine bay.

I use to use the purple stuff but now use Simple Green too. But, I drive to a local selfserve car wash and use their pressure washing. FWIW, the car washes in my county are supposed to capture their runoff water and make environmentally sound. I will try the CD2 next time.

Mendel,

A clean engine bay allows the engine to run cooler not to mention making it a LOT nicer to work on. I also happen to be just a little bit **** about keeping my cars clean. Never have had a problem selling one when it comes time for a new car though, about 10 people are waiting on my next one...

As long as you capture your runoff, you should have no problem with polluting anything but if you are unsure about it, almost any car wash is required to capture and re-use their runoff water. Simple green is not that nasty of a cleaner but still does a decent job if you do not let the engine get too dirty to start with. Gunk or something similar will be required with a really dirty engine and that stuff is not friendly to man nor beast. That is why I keep mine fairly clean and do not need to resort to a heavy cleaner.

doasc,

CD2 is just used on the plastic and hoses. Everything else is just cleaned. By the way, that is not a new engine but one with two winters and 33,000 miles on it. My wifes Pilot looks just as nice however and it has a LOT more miles on it than mine.

In case your are wondering just how crazy I am (my wife knows that I am nuts), every time I rotate the tires, I also clean the backside of my wheels and put a coat of Poorboys wheel sealant on them. Sometimes being OCD comes in handy...

Until Feb. 10, 2009:

I have power washed the area under the hood. This is not much different when driving in a down pour of rain. I agree it keep the engine running at the correct temp and keeps dirt salt and other stuff off the engine components and prevent other problems. You have control over where you place the water. I try not to drown the motor with water.

I doubt a thin patina of dust is going to change your engine temperature at all. Keeping your radiator clear will help. The engine temperature is held at a certain level by the coolant thermostat, and the radiator fan(s) if needed.

I think a lot of people are going to be doing this in their own driveways, and pumping soap/solvent/oil into streams, I'll pass.

Mendel,

Sorry about the delay. I have been soaping down and pressure washing my house today....

If you are washing oil and grease into streams, you need to fix the oil leak on the car. The same with solvents. A bio-degradable soap is fine if washing in the driveway or if you have a grey water trap that is used to water the yard. To each his own but I like my engine clean. If you don't that is fine.

By the way, most people are terrified about spraying water on a hybrid engine with the high voltage lines. I doubt that more than VERY small percentage of hybrid drivers will ever clean their engines becaue of that issue.

Until Feb. 10, 2009:

With the older engines we had to worry with water in the alternator or the distributor being drowned out.

Not so with the TCH, no alternator or distributor to worry with. The 4 spark coils are directly above each of the 4 spark plugs. The coils are covered with a protective cover that also suppresses the valvetrain noise. The car has spark plug wires to deteriorate. Each coil fires when activated by the ECU.

The heavy orange insulated cables are the 288 dc volt cables. The two smaller ones go to the electric Air Conditioner and are dead if the car is off. The other two heavy orange cables come up from the lower rear of the engine. They go up into the front of the Inverter and are well insulated from any water. I'm not sure if they have any voltage in them till you start the car and step on the accelerator.

I once read in the early Prius they used to run the power cables in the roof channels from the trunk. After a few years the new method is that they are encased in two metal body channels under the car. This way they are protected from a crash or from any rock damage.