9th May 2011, 20:00

I washed my Lincoln under the hood, and the spark plugs got messed up. Also, it damaged the voltage regulator. I was upset. I didn't use a dog gone fire hose. I only used a garden hose. Lincoln/Ford. I don't know!

10th May 2011, 22:51

Poster 17:01 said it best!

28th May 2011, 01:53

Washing under the hood of a car would be like taking the lens off a digital SLR camera and using a hose to wash the dust off the digital sensor. At least it would not mess up the spark plugs...

28th May 2011, 09:48

What is wrong with people? Washing under the hood with a garden hose and then blaming the mfgr. Hey: why not "wash the electrical outlets" in their home and see what happens. No wonder people have troubles. They bring it on themselves.

28th May 2011, 13:58

To original poster, you should have had the car running when you washed it under the hood. Unlike what a lot of posters say, you can wash under your hood with no harm being done if it is done correctly. You cannot use a garden hose; tap water is full of corrosion minerals and is bad for a car period. You need filtered water where all minerals are removed. And auto shops carry this foam that you spray over the engine bay area that reduces corrosion and water damage to electronics's and wires, plus it helps clean the dirt and grim.

28th May 2011, 14:02

That's why you check the spark plug wire and make sure it's seated properly before washing.

11th Mar 2012, 19:07

Cars, of any variety, are NOT designed to be washed under the hood. Lots of electrical components under there. You risk damaging electrical components. Think taking a garden hose to your home electronics. Not a good idea. If you spray cold water on a HOT engine, you risk even more damage, but this time to the engine and connected components. Cold water on a hot engine can cause cracking of the exhaust manifold and engine block.

Before I knew better, I used to spray under the hood with the hose to clean the engine bay. I did this to a Ford Taurus, which caused the car to not start for several hours until the water dried. I also sprayed water under the hood of a Buick Park Avenue, causing the dash instrumentation to short out.

If you insist on cleaning under the hood, do it by hand with proper cleaning products.

23rd Apr 2013, 02:14

OK, OK! Wow, yes everybody is right, you shouldn't wash under the hood on a Ford with a 4.6/5.5/6.8L engine. Why? Because the spark plugs/coils are next to the intake manifold on top of the engine. I had a Crown Vic and learned the hard way myself. I had to spend an hour removing all the ignition coils, and then blowing out the spark plug wells with compressed air before the engine would run without missing.

I also had a Camaro, which I regularly washed the engine and never had a problem. The spark plugs were under the exhaust manifold on the bottom of the cylinder heads, and weren't as susceptible to moisture.

The above Ford design is not flawed, as neither of my cars were really designed for the top of the engine getting wet; it's just one liked getting wet more than the other.

23rd Apr 2013, 19:41

I don't think any car built 90 or newer should be washed in the engine compartment. Most cars by then had fuse boxes under the hood, and luxury makes put ECMs, air bag controllers, and ABS controllers etc.. under the hood.

23rd Apr 2013, 22:12

"If you insist on cleaning under the hood, do it by hand with proper cleaning products."


25th Apr 2013, 16:26

I show my Mustang at car shows, so a clean engine compartment is a must. I always clean everything by hand using a rag and proper cleaning agents. I never spray water under the hood. Yes, it's more effort to hand clean everything, but it is far safer and does a better job. The best bet is to clean often so there is less dirt to remove.

13th Dec 2015, 17:33

Cars should be "washable" under any set of conditions. I too am upset with Ford. I had a Focus. My friend used the car and smoked in it. I took a pressure washer and tried to clean the inside roof liner, and the seats to get rid of the smoke smell. After it dried, the roof liner started to come down, and the seats have never been the same. Plus, the inside has a musty smell now. FORD/LINCOLN NEVER AGAIN.

14th Dec 2015, 14:19

I show my cars and use microfiber cloths, no rags. I use paper towels only on the glass. I like Invisible Glass cleaner. I use absolutely no silicone based products in my car. On my tires, no silicone to accelerate dry rot. I buy most all my products from US Auto Supply in Philadelphia. They have an online site. I drive Corvettes, but the same applies here. I don't spray water ever in the engine compartment. You can do serious electrical damage. I even use all gel batteries vs liquid acid types to leak perhaps into the computer.

Cleaning wheels has to be the least pleasant of all. I do not buy acid based wheel sprays, and putting a high quality cover over the car including separate wheel covers in a garage saves a lot of prep work. Staying out of car washes is not a bad idea with harsh soaps. I know a lot of guys worse than me on cleaning. They have lifts at home and clean the undercarriage. If it's a bad day out, take a driver car vs a car you show.

Good luck!

14th Dec 2015, 19:33

Anyone who uses a pressure washer to clean the inside of a car shouldn't complain about the consequences...

17th Dec 2015, 00:39

Sure he meant under the hood, still a no no. Besides the electrical system and engine on or off, it's a big risk. Plus getting under the engine seals, especially utilizing a heated pressure washer. I saw a guy bend the fins on his radiator. That was a really pretty sight. Don't suspect any trophy is on the horizon. If you have a 4 wheel drive off roading, it's nice to clean the undercarriage.

17th Dec 2015, 19:29

Electrical systems are all under covers, so there's no concern about those. That'd be like saying it's not safe to drive in the rain.

18th Dec 2015, 13:44

What kind of car has the seats and roof liner "under the hood"?

18th Dec 2015, 16:31

Pressure washers push very high concentrated PSI water into sensitive computers and can cause very serious expensive damage. You can do the same with a hose. Don't think with heat buildup and time that everything is totally sealed. You may spray indiscriminately all under the hood, but one day it comes back at you. Plus you may get water into the intake. Bad advice. Carry an umbrella and stay dry as well.

20th Dec 2015, 01:09

Water gets into the intake in a rainstorm or after driving through a puddle. Not a big deal unless there are small bits of rubbish in the water.

21st Dec 2015, 12:32

Try spraying 3000 PSI with a pressure washer. Why argue and even attempt it? My concern is the electronics more than fuel contamination. Of course pushing water through the valve cover seals, especially with a hot pressure washer, is helpful as well. I will buy degreaser and wear gloves doing by hand. If you are rebuilding an engine, spray away. Try spraying your radiator fins and admire the look. It's not very pretty with a quality pressure washer.