What is the best and safest way to clean an engine?

Anything suspect cover with saran wrap and / or use a water displacment spray -WD40

To state that an engine compartment and components are made to be weatherproof because they are in semi-open environment is a naive excuse for steam or high pressure washing (usually used to get the job done quickly as opposed to safely). The electrical and other engine components are made to be water repellant (very different from waterproof) providing the water is from a low pressure source; i.e. water migration from going through a puddle of water. Steam will subject the engine components to high pressure and heat getting into places that are not made for either of these conditions.
 
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I agree that using a high pressure washer could lead to problems, but from what i know, and from what i have hear, I personaly have not heard that a wash with a garden hose will do anything. Now i am speaking of newer cars, not older ones. I have am on forums about 3 hours per day, so i hear alot of things, but never a damaged engine component from washing. Now im not saying it has not happened, i just havent heard of it. so, has any one ever personaly damaged and engine, or any engine component with a regualar garden hose?
 
ZoranC said:
... and don't get me even started on service "specialists" ...
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:applause: :applause: :applause:

and just who would profit if he happened to be wrong ??

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and yes I have damaged my motor, twice, while using water under the hood. Now I was not to blame, and ultimately it became a warranty repair but dealer was none to happy to replace the Opti-spark unit on my TransAm . Both times I lost car for several days, all because I insisted on spraying down motor. So now, I follow a detailing regimine that should never require any down time !
 
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1996 Ram Air T/A .... The Opti-spark (think distributor) was used and placed on all Lt-1's in same place. Thus very susseptible to water, and heat damage. Dealer could not understand issues, until the second time and they spoke of water in unit. I then fessed up that was cleaning motor. Needless to say a third time would NOT have been in the warranty cards.
 
"Modern engine designs are tending to do away with the distributor and coil, instead performing the distribution function in the primary circuit electronically and applying the primary (low-voltage) pulse to individual coils on top of each spark plug (Direct Ignition or coil-on-plug). This avoids the need to switch very high voltages, which is very often a source of trouble, especially in damp conditions."-wikipedia(distributor)

Maybe in well built new cars like BMW, AUDI, M-B, and Porsche, washing the engine with a water hose is no problem. Maybe your distributor was poorly engineered, and thus lead to its failure(was it O.E.M.?) but in any case, you did have damage caused by washing the engine, the only case i have ever heard of, any one else damage their cars engine components.
 
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there was a funny little statistic that I often look back on when hearing comments on how much better built Mercedes (not even in JD Powers top10 any longer), Audi and BMW are.

When one looks at the money initially spent, plus all the upkeep and costs outside of warranty, no manufacturer other than Lexus has ever shown any appreciable difference in total ownership costs. Infact, some suggest this is why BMW and Audi now try and offer free scheduled maintenance.

The opti-spark unit was not a true distributor, but most like one. Corvette comes with individual coil on each cylinder bank, and thus was Lauren was originally warned not to get water under covers. Which would be quite easy based upon this design. I still stand by little water under the hood, and never pressurized.
 
killrwheels@autogeek said:
there was a funny little statistic that I often look back on when hearing comments on how much better built Mercedes (not even in JD Powers top10 any longer), Audi and BMW are.

When one looks at the money initially spent, plus all the upkeep and costs outside of warranty, no manufacturer other than Lexus has ever shown any appreciable difference in total ownership costs. Infact, some suggest this is why BMW and Audi now try and offer free scheduled maintenance.

The opti-spark unit was not a true distributor, but most like one. Corvette comes with individual coil on each cylinder bank, and thus was Lauren was originally warned not to get water under covers. Which would be quite easy based upon this design. I still stand by little water under the hood, and never pressurized.
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yeah, I've heard that to replace simple thing like power window motoer will cost you arond $1,000. And this is minor work...
Better have that additional warranty purchased...

BMW actually offers that free scheduled maintaince to outsell Mercedes Benz.
Scheduled maintaince for Benz come out of your pocket...maybe Gary can let us know how high are those bills?:confused:
 
i think they are worth the money. i got my extended warrenty, the way i drive, i am going to need it, somethings bound to break.
 
Lauren, this is a picture of my engine. I do not have fuel rail covers on it, so you can clearly see the coil packs. I "photoshoped" some leaders and text so you know what's what. Granted, this isn't a vette, but our engines are the same, and the componets will look the same, but may be in diffrent locations (ie: pcm and battery).

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You should be able to see the fuse box (should be close to the battery if memory serves). PCM should look the same as well. Hope this helps.

Again, nothing more than a trickle of water to rinse the cleaner out. Chances are, a pressure washer could be used with no problems, but in the off chance you had a split in a wiring harness, or a connection to a wiring harness connection was slightly exposed, fuse box not properly sealed, etc., all that water would be forced into those areas with a pressure washer. Just my thoughts on the matter.
 
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Thejoyofdriving said:
I agree that using a high pressure washer could lead to problems, but from what i know, and from what i have hear, I personaly have not heard that a wash with a garden hose will do anything. ... I have am on forums about 3 hours per day, so i hear alot of things, but never a damaged engine component from washing. Now im not saying it has not happened, i just havent heard of it.
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What is the percentage of cars whose engine was washed vs ones that have been posted on forums about? If tree falls in the forest and nobody hears it did it not fall?

Forums are just a starting point and are not a replacement for brain and experience. Not to forget they very often have "forum noise" and are very often "garbage in garbage out".

So, let's please stop using refrain about forums. It is starting to become very annoying.
 
thank you, gregsgoat! yours looks a lot more uncovered than mine. thank you - that was great!
 
ltoman said:
thank you, gregsgoat! yours looks a lot more uncovered than mine. thank you - that was great!
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your correct Lauren, same engine but without the painted covers. See how the coils literally just sit under those covers though, waiting for some water to slow your day. Wash lightly ...
 
As it's already been stated, be very careful when cleaning the engine bay.
I have to agree with the opti-spark comment. When I had my '94 Trans Am I nearly made a $1000 mistake! Each and every vehicle is different. I often wash my '02 Avalanche engine bay without hesitation. Had I not researched first the make-up of the LT1 I would have had a costly repair. Not to say I didn't clean that engine bay, I just had to do it all by hand and a spray bottle.
As I say.... if you have any doubts, don't do it.
 
Wow, a lot of misleading info in this thread.

What the do you guys think happens when it rains? Ever notice how water somehow gets to the underside of the hood (most wont because they have that foam pad thing on the back of the hood). The only things I cover are the MAF, coilpacks/distrubitor, and fuse box.

A long time ago, when the computers in cars were in their infancy, they were not completely sealed. If you have a car with over 200K, then you might want to be a little more careful about the wiring harnesses. But for cars today, you probably wont need to cover anything in the engine bay.

And i just use simple green sprayed fullstrength on everything after a very light pre-rinse, then i go at the crevaces with a bottle brush, and the larger parts with a wheel brush. Rinse, dry (your choice: air dry, leaf blower, etc), and spray some tire shine on everything and your good to go. Takes no more than 30 mins.
 
investinwaffles said:
What the do you guys think happens when it rains? Ever notice how water somehow gets to the underside of the hood (most wont because they have that foam pad thing on the back of the hood).
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When it rains and car is not moving water does not soak engine vertically down. When car is moving water droplets (droplets, not 100% density water) is following flow of air, which means lots of it gets pushed to the sides of the engine or above the engine, but it is not falling vertically down, and what does fall down is much less intense than wash straight down.

investinwaffles said:
And i just use simple green sprayed fullstrength on everything after a very light pre-rinse
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Simple Green full strength does not end up staining anything for you?
 
Just washed the engine bay on my dads porsche again, i did cover 1 thing though, the air intake, alot of porsches the air intake is open and facing up, but still water got in the intake and no problems. when it rains water goes inside the intake to, there is probably some sort of drain.
 
It isn't the engine you have to worry about... things like the altenator, fuse boxses, coils, etc is what you need to be careful with. Same with the air box... If you spray down into an altenator and let it sit for 4 hours before starting or drying the engine I think you'd have a problem... as for Ford vs. BMW vs. Audi... they all have engines and the same parts... just one costs a lot more than another.

Now back to Lauren's original question... the safest way to clean an engine... don't use water. If it is fairly clean and you can keep up with it, follow killrwheels advice of using a damp towel and maybe some APC to clean the accessible areas and then dress with some type of protectant... do this every month or two and you won't run the risk of wrecking and engine component during a detail.
 
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