Cleaning the engine compartment

I suggest that you avoid getting electrical connectors wet, and do not get water on the engine valve cover. The spark igniters have rubber O-ring seals but the seal is not perfect and water can drip down into the spark plug wells, which will cause ignition misfire.

My procedure is to use the minimum possible amount of water, use paper towels to dry everything off, and take the car for a short drive so that engine heat will dry off the remaining parts.

 

One of our regulars was Frank Hudon, who I haven't heard from in at least 2 years. After washing his motor, he would actually remove the coil packs and use compressed air to blow everything out

He claimed a fair amount of water entered the spark plug wells after routine engine washing. I can only imagine what a high pressure wand at the car wash would do

 

It might take months or years for a problem to manifest, and then it's too late. Toyota issued a TSB to correct the hood gasketing on some early builds because rainwater could enter the drive compartment; the thing is clearly intended to stay dry.

 

Over 5 years and 192,000 km I never cleaned my Prius engine bay once. Toyota motors are generally not "leakers" it may have been a bit dusty, but absolutely not oily or dirty

 

I clean my engine the same way I clean my bike.
If it's really dirty use a damp sponge and detergent then a sponge damp with clean water. Then, or if it's just a little dirty use Mr Sheen and a soft cloth to clean the engine leaving a layer of wax to protect the engine and make it easier to clean next time.

Spray on, wipe over to remove dirt, then buff once dry. May need 2 shots in some spots.

 

there are some good videos on youtube about it. But not for the prius. I normally just wipe it down everyonce in a while, kind of the same way sparks does his. Using a gentle stream of water to lossen dirt and just some Dawn dish soap. No problems yet

 

I have no problem washing the engine compartments of different cars for the last 40 years using a spray on degreaser and a garden hose. I recommend not to use a pressure washer, it could cut the wiring insulation or get water into areas that you don't want to.
Just make sure not to spray to much water to the spark plug hole area and the distributor.
For cars from the late 80's, all the electrical sensor connectors are water proof type with the exception of some 12V supply wirings.

 

When I have looked in my engine compartment, I have been impressed at how clean it is. I see no grease, the covers are clean and new-looking. The last time I changed the engine air filter, I did take a paper towel and wipe dust off the surfaces.

I have a 2004 with 86K on it.

 

surprising my 2007 get's very dirty, several shop towels later black brown dirt still comes off in the nooks and crevices. Lots of fine dust

it's the desert after all

 

Take off that cover on top of the rad. It allows you access to the radiator cap, and also allows you to inspect between the A/C condenser and rad core. That fine desert dust can actually stick to a radiator core, then drive in the infrequent rain and that dust turns to mud/clay.

It can then restrict airflow and cause weird overheating problems. There are neat little gadgets you can buy to safely hose out your radiator core fins

Automotive Tools Specialty | Auto Mechanic & Technician Diagnostic, Testing Equipment | Thexton

You want the #467A. It works by allowing you to safely cover the entire core, as the water comes out at a 90 degree angle so it sprays orthogonal. Otherwise, if you just try to spray straight down at the fins, you will bend/collapse the fins and make the problem much worse

I'm well aware of the problem of fine desert dust. I used to live in Mesquite and St. George

 

I used to"gunk" down all my engines , followed by a hose water wash, 30 years ago.

I stopped 'cus no matter what procedure I used condensation always found its way under the distributor cap. (wouldn't start)

It would take a couple of hours to completely dry.

So...........I imagine it is not the best thing to do anymore especially with all of the elect stuff under the hood nowdays.

Just my experience though!!!!

 

Well, if you really do want to hose down your motor, it would probably be a good idea to then remove the coils and use compressed air to blow out the tube.

That way, if any water did find its way into the coil tube, you can get it out

 

Just had mine serviced at the dealer, they left a mess under there.. Not sure how they use an oil gun and still manage to get oil everywhere in the bay. I need to get it cleaned up. I was going to do it, but I will see if they will otherwise I will try the sponge method mentioned above

 

I would be more concerned about how overfilled the oil is now. Dealer service is famous how un-accurate they are when re-filling and how little they care about it.
Its the gun attached to the vat oil.


Just get a rag and wipe off as much as you can. Bad idea to get anything wet under as there are hundreds of electrical connectors.
Would be alot of fun to all of a sudden get a misfire that comes and goes turning your nice car into a misery.

Professional engine detailers use steam.