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So I've heard both sides of this argument, and am curious as to what you all think: When you wash out everything under the hood, do you do it with the engine running or not? My father always did it with the engine on, and several people have completely flipped out when they saw me do this, so I stopped...
I always do it with the engine off, usually cold, and usually take off the air cleaner, replace with a watertight carb cover, and spray the inside of the cap with WD40 afterwards.
I also usually spray down with Simple Green beforehand and wash with steam (Jenny steam cleaner).
Diesels with injection pumps -must- be cleaned with the engine off, or else the difference in temperatures can cause the fuel pump plungers to bind and destroy the pump.
Dpends on what year? The last time I blasted one it was a 94 GMC and it screwed up some of the electronics, The winsheild wipers gave me problems from there on out......I quess I would not spray unless it was an older model vehicle. running or not running
I spray "Gunk" on a warm, not hot engine.
Let it sit for a few minutes.
Then, wash it down with a garden hose.
I don't like high pressure on the newer engines.
Never on a running engine.
I wash the engine compartments of my vehicles at least once a year. I spray a 50/50 mixture of Purple Power and water over everything when the engine is cool. Let it soak for 5 minutes then rinse it off with a garden hose.
I use a pressure washer on a cold motor. Here's a tip: When your done cleaning and everything is dry, hose the entire engine compartment with tire foam. Let it sit for a few days, or longer. The oily residue will attract dust like crazy and look like h$ll. BUT, it also is slowly soaking in and loosening oil / dirt missed in the washing. Pressure wash it again and it looks unbelievable. I do the tire foam once a year and wash it regularly. The more you use the tire foam the better the result and its much easier to keep looking good!
i always cover the carb or throttle body well, then as much of the power dist box (or distributor) and wash way, then dont even try to start it for a couple of hours
In my f350, I liked to have it running cause the one time I didn't have it running, it wouldn't start after and I had to wd40 the dizzy to get it going.
On my dakota, Sometimes running, sometimes not. leaving it run just gives me a sense of security, it never had any apparent adverse side effects.
For newer Fords with COPs (coil over plug) do not wash the engine with a sprayer of any kind. The COPs are prone to failure from this. Sometimes they fail immediately and develop a misfire. Sometimes they never fail. Sometimes they fail days or weeks later after water has had an opportunity steam into the coils and condense on a cool night. I learned this the hard way after I had a coil fail 2 days after washing the engine and then 2 more go out 3 weeks later. For my 2006 I use a soft cloth dampened water and cleaner, wiping down everything by hand. You could cover electronics with plastic and spray wash the engine bay but I guestimate that by the time you've completed this you could have already been done with the 30 minute wipe down.
IDK what kind of vehicle you are talking about, but if this is a daily driver, why do it at all? You're just asking for problems.
My 2000 has never had an engine bath in the 4-5 years I've owned it and it's hardly even dirty. A little dust and that's about it. It's parked outside all the time and it sees plenty of mud and offroad at my property. They are water cooled, so it's not like it needs to be done.
Maybe I don't get it. It wouldn't be the first time.
If you can't blow the distributer cap off, then your washer isn't powerfull enuogh ha ha. I wash it with the engine off so the fan doesn't blow more water back into the engine. I use light presure and just hit certain dirty area's, not soak the whole engine. As Ken stated, these new engine can be touchy. When I washed my 89 jeep comanche engine, all was good untill I went to start it, I burned up 2 fusable links. I smelled it and then saw the smoke, I was bumming!!!! Luckily it was a cheap easy repair once I figured out what I did. I hate the smell of burning wires, that tends to suck in a big way.
IDK what kind of vehicle you are talking about, but if this is a daily driver, why do it at all? You're just asking for problems.
My 2000 has never had an engine bath in the 4-5 years I've owned it and it's hardly even dirty. A little dust and that's about it. It's parked outside all the time and it sees plenty of mud and offroad at my property. They are water cooled, so it's not like it needs to be done.
Maybe I don't get it. It wouldn't be the first time.
Mike
Its not my dd, but after I go off-roading with it there is mud, plant matter, and all sorts of goodies that just coat the engine. I'm sorta a neat-freak and would like all of that stuff off... maybe I'm just being too picky.
Also, when flushing a radiator that has rust in it, it has a tendancy to spray EVERYWHERE and make a huge mess...