cleaning an engine?

2000SuburbanLS · June 20, 2004

Can anyone tell me the best way to clean an engine and compartment without damaging anything? Is it ok to just spray it down while running?

pacodiablo · June 20, 2004

Do not spray it while it is running. Allow the engine to cool down completely before spraying water on it. It is a good idea to cover the battery, fuse box and air filter housing before spraying, but many people don't. Do not use a pressure washer, use a regular garden hose and spray loose dirt off. Then spray Simple Green or another degreaser (read instructions and warnings!) on the engine and let it sit for a couple of minutes, then hose everything down again.

5.3LSilverado01 · June 20, 2004

I have heard and always did use hi preasure water from the coin wash while engine is running. Something to do with the alternator drying it self while spinning.

pacodiablo · June 21, 2004

Spraying water on a hot engine could, in extreme cases, cause the block to crack and do other damage. High pressure water can force its way through gaskets and seals causing damage.

carguru · June 21, 2004

Best to wait until everything cools. Just spray down with Simple Green. Let it soak for a little while. Rinse with a garden hose. While pressure wash will remove stuff faster, I'm alway afraid if done wrong you could damage seals that might now otherwise be damaged with low pressure. I just washed mine down this afternoon to get the residue from my oil change off.

R Dogg 56 · June 21, 2004

It is a good idea to cover the battery, fuse box and air filter housing before spraying

What would be best for covering these? I doubt just any old bathroom towel or a semi-clean utility tarp would suffice.... or would they?

awdvkd · June 21, 2004

I've been using a carwash high pressure hose to clean engines for 30 years and as long as you don't put the high pessure spray too close to the engine or electrical components you won't hurt anything. The trick is to let the degreaser do the job. Spray it on the engine and let it soak a few minutes then use the spray to rinse, not blast the engine. I have always let the engine idle while doing this, it allows the engine to cool down and if the engine starts to stumble you know to stop spraying in that vicinity. As for getting water in the electrical or the alternator, what do you think happens when you are out wheeling or driving in a heavy downpour. The secret to the whole thing is do it often enought to where the engine compartment doesn't get so dirty that it takes a blast from a high pressure hose to clean it. My 2 cents. Good look

99silveradoz71 · June 22, 2004

Yes, regular cleaning is always good. I spray with simple green first, let it sit, then use the mist adjustment on my 6-way hose nozzle...that way it's a lot more controlled and a lot less pressure.