Cooling Your Engine Off

[-Alero-]

i was talking to my friend the other day, and he drives a 89 240sx, and whenever he goes to the car wash he sprays his engien down with a hose. ive seen him do it and one day i say to him, isnt that bad for your engine, to spray it down with water right after you were driving it. (it was at operating temp) he said "no ive never heard of anything like that" so i got to thinking, that its bad to spray your engine down if thier is aluminum on it because aluminum cracks when it changes temperateure fast. well my main question is, do we not have cast iron blocks and are we able to spray our engines down right after it reaches operating temp? (3.4)

I would never spray down a hot engine... Just think of those extreme temperature changes might be doing to your engine...

If you ask me, he is just inviting trouble with open arms.

[-Alero-]

well the exhaust manifold gets up to 2000 degress, and the rest of the engine only gets up to 200. his car is fine everytime he does it.

How long has he been doing this for?

[Vtolds]

I spray my motor down all the time at the car wash using there engine degreaser, I havent cracked my motor yet. On my cousins old race car we would pour cold water on the radiator to cool it instantly but we also left the car running for fear of cracking the radiator or the block.

isnt this why our rotors warp, cooling quickly unevenly?

^^^ Yes it is why our rotors warp most of the time, some of the other reasons are from hammering down on the brakes hard at high speeds.

so doing that to an engine wouldnt be a bright idea i take it. thats like jumping into a cold pool when its 100 degres outside. instant heart attack.

Yea that would be correct, especially with an alluminum block and heads. Alluminum is bad for major heat changes that happen quickly. Cast iron blocks aren't as bad but it still is a not so good thing to do.

[b-spot]

Here's something fun for you guys.

Look up the mass of an aluminum engine.. say the 2.2 ECOTEC block. Now calculate how much energy it holds to have its temperature at 200 degrees.

Now calculate how much heat it takes to boil a gallon of water.

Ever wonder why if you spray your engine when its hot the water just boils right of instantly and the engine is still hot? Thats why.

B-spots science lesson of the day. Informing retards one at a time.

[MikeSS]

Originally posted by b-spot@Jan 10 2005, 02:59 PM
Here's something fun for you guys.

Look up the mass of an aluminum engine.. say the 2.2 ECOTEC block. Now calculate how much energy it holds to have its temperature at 200 degrees.

Now calculate how much heat it takes to boil a gallon of water.

Ever wonder why if you spray your engine when its hot the water just boils right of instantly and the engine is still hot? Thats why.

B-spots science lesson of the day. Informing retards one at a time.

yeah, water touches your engine and ecspecially your header/exhaust all the time when you drive in moderate to heavy rain....a portion of that spray coming off your car on the highway is the water smoking off your engine.

Ever been folowing a car who hits a bid puddle and his/her car is still steam a few seconds later?

[b-spot]

Whats this you say MAlero?? When the roads are wet water could be spraying up to your TWO THOUSAND DEGREE exhaust manifold?? :o :o :o

Doesn't this mean those of us with Aluminum blocks will have our engines crack when it rains out? or ever worse... SNOWS!!

I think I should buy another car so I can leave my precious $5000 alero in the garage for when the roads are wet!!

[MikeSS]

poop, I think the only reason I can get anywhere in the snow with my lowered alero is because my exhaust is melting the snow beneath my car

[-Alero-]

so..........do the 3400 have cast iron blocks or aluminum?

[AGT]

and whats the exhaust manifold supposed to be made of?

[-Alero-]

looks like aluminum to me

[b-spot]

Originally posted by Alero-@Jan 10 2005, 09:20 PM
so..........do the 3400 have cast iron blocks or aluminum?

Cast Iron, but if you read above you'll realize it doesn't matter.

[-Alero-]

Originally posted by b-spot+Jan 11 2005, 12:23 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (b-spot @ Jan 11 2005, 12:23 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-Alero-@Jan 10 2005, 09:20 PM
so..........do the 3400 have cast iron blocks or aluminum?

Cast Iron, but if you read above you'll realize it doesn't matter. [/b][/quote]
lol nice! thanks

I would think that if you kept spraying water on it for like a minute or so, so that the block isn't evaporating the water anymore, that it would cool it off faster than it is designed to cool off at and that could possibly end up cracking your block. Couldn't it? I know that if you just put a few drops or a few minor sprays that it will evaporate off the engine immediatly.

spraying the engine wont matter at a power wash. its high pressure water going into teh brushes of the alternator and distributor (we dont have a distributor so it doesnt mattetr)