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Old Apr 19, 2019 | 11:00 PM
  #1  
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Default Engine Cleaning

Hello out there!
I would like to clean the engine on my 94' C4. What is the best way to do this and protect the OptiSpark from getting wet. Is a low psi power washer even usable or just spray de-greaser and rags.
Thanks in advance!
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Old Apr 20, 2019 | 12:00 AM
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Spray 'er down with a power washer. Make some effort to avoid directing at toward the opti. I try to spray my engine from front toward the rear so it drains off the back of the engine. Technique has worked great for 10 years now.

Easy, fast, works.
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Old Apr 20, 2019 | 06:51 AM
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You just don't want to soak the opti with direct water. I have kept my engine fairly clean since day 1, but I use Simple Green and garden hose with a sprayer, making sure to avoid the opti area when rinsing. After done, I use a electric leaf blower to dry the engine...causing my neighbors to give me perplexed looks, although they are use to my leaf blowing technique not just for the engine, but the car itself after washing.
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Old Apr 20, 2019 | 09:47 AM
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Default engine cleaning

Thank you both for replying. I've just heard so many nightmares about getting the Opti wet that its frightening. I think I'll crawl underneath and at least try and wrap it with some tin foil before and careful and gentile wash.
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Old Apr 20, 2019 | 02:30 PM
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I washed the engine on my 92 coupe. Tried not to get the Opti wet but when I went to start her up, crank crank and no start. I used compressed air to dry it all out. Still no start. I pushed her back into the garage and tried to start her up a couple hours later. VROOM and a big puff of black smoke and she was back to normal. Don’t know if the Opti got wet or what but once everything dried out it ran fine again. I probably got lucky. YMMV.
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Old Apr 20, 2019 | 05:03 PM
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It's unlikely that you're optimistic got wet (inside). When they get wet inside, it could take days to dry out, w/o taking it apart.
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Old Apr 21, 2019 | 09:55 AM
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I don't think it's worth the risk using a pressure washer. Rags work for me.
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Old Apr 21, 2019 | 12:06 PM
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Originally Posted by fredk
I don't think it's worth the risk using a pressure washer. Rags work for me.
I agree. It's just not worth the risk when simple green, rags & brushes will do the job.
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Old Apr 22, 2019 | 01:55 PM
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I just stuff a few rags around the WP/opti area then wash with hose nozzle. Any dirt or grime in that area should be cleaned manually IMO (old tootbrush, etc).
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Old Apr 22, 2019 | 08:06 PM
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This is from a 1989 L98, but you get the point.... Tape up what needs to be taped and then just get after it.
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Old Apr 22, 2019 | 10:55 PM
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easy off oven cleaner actually works very well for those grimy places... i have done several total rebuilds and cleaned up old greasy engines to an almost hot tank bare looking block using easy off oven cleaner and a scrub brush.. rinse it off with a garden hose. it isn't strong enough to melt paint or anything but it knocks the snot out of grimy crud.

Last edited by bud40oz; Apr 22, 2019 at 11:01 PM.
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Old Apr 22, 2019 | 11:39 PM
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Default Be careful!

In addition to totally avoiding the area around the Opti spark, AVOID spraying water with any force on ANYTHING that has an electrical connector. AND avoid hard sprays in the areas of the alternator.
And as mentioned above use a leaf blower.
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Old Apr 23, 2019 | 10:08 AM
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Originally Posted by billschroeder5842
This is from a 1989 L98, but you get the point.... Tape up what needs to be taped and then just get after it.
Nothing on an L98 heeds to be taped. Get the power washer out and blast the bejeezus out of it. Fast, effective, easy.
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Old Apr 23, 2019 | 10:37 AM
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I soak the whole thing down with Awesome from Dollar Tree. Let it soak for a few minutes and hit it with a garden home with a gun nozzle. Works great and super cheap.
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Old Apr 23, 2019 | 11:27 AM
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Originally Posted by bac22
After done, I use a electric leaf blower to dry the engine...causing my neighbors to give me perplexed looks, although they are use to my leaf blowing technique not just for the engine, but the car itself after washing.
lol, glad to hear I'm not the only one that uses a leaf blower for drying.

Only difference is that mine is gas.
I have also used it to clear snow from the cars...

Last edited by Gibbles; Apr 23, 2019 at 11:27 AM.
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Old Apr 23, 2019 | 01:34 PM
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Originally Posted by Tom400CFI
Nothing on an L98 heeds to be taped. Get the power washer out and blast the bejeezus out of it. Fast, effective, easy.
I would cover the HEI... Quick plastic bag wrap...
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Old Apr 23, 2019 | 03:12 PM
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Yeah, you could. I"ve sprayed the bejeezus out of my HEI's over the decades...never had a hiccup from it. There's not a lot in there, that cares about water.
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Old Apr 23, 2019 | 05:26 PM
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Originally Posted by Tom400CFI
Yeah, you could. I"ve sprayed the bejeezus out of my HEI's over the decades...never had a hiccup from it. There's not a lot in there, that cares about water.
i always thought if you leave the engine running while you power wash off the engine, you are fine anyways. done it many times. that stuff goes back to the old points ignitions i think, dodge mainly. those things would stop running in a heavy rain storm lol
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