Engine bay cleaning, hot vs cold

PremierAuto_NJ

PremierAuto_NJ

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Just a funny observation I felt like sharing. A few years back when I was learning how to detail I was taught that when cleaning the engine bay to have the engine running during. I was told the heat would seal off the vulnerable compartments by making any water turn to steam before entering. I was taught this method by a very successful detailer who made a great living working on almost entirely exotic cars. Now granted that I have my own business and am liable to any damage, I only detail cold engines and am very careful. But I just find it interesting that I detailed at least 50 running engines when I was younger and never caused any damage, and they turned out exceptionally clean. What do you guys think? With all the reading I have been doing everyone states that you will damage the wiring or the engine components in some way.
 
Before I took up detailing, and started reading here on AG, I would take my cars to the self-serve and leave them running. Spray on degreaser, let it soak, high pressure rinse and spot free rinse. I left the car running because I didn't want to not be able to start it sitting in the bay. Never had any problems, but I don't do it that way now.
 
PremierAuto_NJ said:
Just a funny observation I felt like sharing. A few years back when I was learning how to detail I was taught that when cleaning the engine bay to have the engine running during. I was told the heat would seal off the vulnerable compartments by making any water turn to steam before entering. I was taught this method by a very successful detailer who made a great living working on almost entirely exotic cars. Now granted that I have my own business and am liable to any damage, I only detail cold engines and am very careful. But I just find it interesting that I detailed at least 50 running engines when I was younger and never caused any damage, and they turned out exceptionally clean. What do you guys think? With all the reading I have been doing everyone states that you will damage the wiring or the engine components in some way.
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I never spray water on a running engine. There's always the possibility of the air intake or PCV system sucking water in. And there's also the possibility of causing a short by spraying water into electrical while it's in use. A cold engine will allow much more dwell time for APC and degreasers. I degrease, rinse, blow dry, and then run the engine to operating temp with the hood closed to finish off the drying process.
 
Just02896 said:
I never spray water on a running engine. There's always the possibility of the air intake or PCV system sucking water in. And there's also the possibility of causing a short by spraying water into electrical while it's in use. A cold engine will allow much more dwell time for APC and degreasers. I degrease, rinse, blow dry, and then run the engine to operating temp with the hood closed to finish off the drying process.
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I should have added that even in my inexperience I never sprayed the alternator or near the intake. But yeah I just think back on the expensive cars I worked on and gringe over the damage I could have caused!
 
I do believe that the ability to damage a modern car engine with a consumer grade pressure washer, using a fan tip, at normal distances from the surfaces is greatly overstated.


When I was in HS, I worked for a production detailer for about a week.

We used a very high-pressure PW. It would cut a cinder block with the pinpoint tip. We used it to power wash engines, while running.

That being said...on work trucks that were going to the wholesaler, we would sometimes power wash the INSIDE of the vehicle.


Has anyone seen an engine damaged by a consumer grade or coin-op PW?
 
allenk4 said:
I do believe that the ability to damage a modern car engine with a consumer grade pressure washer, using a fan tip, at normal distances from the surfaces is greatly overstated.


When I was in HS, I worked for a production detailer for about a week.

We used a very high-pressure PW. It would cut a cinder block with the pinpoint tip. We used it to power wash engines, while running.

That being said...on work trucks that were going to the wholesaler, we would sometimes power wash the INSIDE of the vehicle.


Has anyone seen an engine damaged by a consumer grade or coin-op PW?
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Thats what I am saying! I see some rag tag operations as well as professionals use a power washer. I just use gentle hose water and degreaser. Someone told me that "experts" don't give modern engines the credit they deserve on durability and resilience.
 
I was hoping for some good answers here myself as I have just been doing everything by hand with APC and gentle water flow from a hose. while it works, there is some deep down hard to get places I miss. This is on my own car and have not charged anyone for the service yet.
 
I have done hundreds of engine bays. 90% of them have been done by spraying with degreaser, agitating, spraying off with high pressure, then dressing. In all that time had a slight problem in one 70s model truck that was easily remedied with a little compressed air. Modern engines are pretty fool proof.

Sent from my SAMSUNG-SM-G900A using AG Online
 
Working at a volvo dealership and Chevrolet dealership as a detailer, we would degrease the engine bay and pressure wash them clean and not think twice about it.

Although these were mainly new cars so we didnt have to worry too much about damaging anything.
 
I would never clean an engine that was running, too much personal risk. Hot or cold, doesn't matter.
 
Warm maybe but hot...not so much.Most exhaust manifolds are cast iron and what happens when a liquid meets hot cast iron? Potential to crack them.
 
PremierAuto_NJ said:
Now granted that I have my own business and am liable to any damage,
I only detail cold engines and am very careful.
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• Ever faithfully follow the directions on how
to use Gunk to clean an engine/engine bay?
-Warm; Cold; Warm; then Hot. :eek:

• How cold is too cold?

[ame=http://www.youtube.com/watch?v=SQ5Rsz4oveE]Miracle Detail - Engine bay cleaning and detailing with the Polar jet machine and dry ice. - YouTube[/video]

Bob
 
How often should you clean the engine. I degrease then wipe down as much as I can. There's stuff all over the place. Difficult to clean. 2013 accord. I hose down with a mist spray. I would think too much water over time would eventually do some damage.
 
I've used Griot's cleaner and dressing with great results. I spray the cleaner first on a cool dry engine and let it soak for 15min. Then I start the engine and spray it down, without concentrating on the air cleaner or alternator. Cover the air cleaner with a plastic bag first. Then i get out my blow dryer and dry the engine bay, before I saturate the engine bay with the dressing. Let it soak and sit for at least 30min prior to use. I've done this several times w/ no issues. Engine bay looks brand new.

I use a wheel brush on the engine compartment to loosen grime or dirt, prior to the rinse.
 
I've always done cold...don't want to crack anything. Use a pressure washer, from a distance so really not all the much water gets put in there. Never running. Simplegreen, maybe a brush, then rinse and blow dry with an air compressor. Never had any problems.
 
What are you gonna crack? The engine doesn't run that hot, nor are you dumping buckets of ice water on the engine. Using tap water to rinse the engine will cause no harm to a cold or warm engine.

Do you drive in the rain? How do people drive in sub zero snow storms? You'll be fine...
 
At a coin-op my buddy's dad owns a guy left his car running. Sprayed degreaser on the motor, and power washed it. Something happened and the car caught on fire and burned up, along with burning the stall the guy was in. He obviously did something wrong.
 
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