how long for engine to cool down with hood open to change plugs?

[apollo18]

once a vehicle is at operating temp and i decide to park it and keep the hood open (to further increase cooling), how long is a safe bet until the engine is cool enough to change out the plugs? just trying to gauge an approx time. vehicle will be in shade with hood open with 75f ambient temp if that matters

i know tons of answers will be regarding to just do the plugs in the morning after its off for a few hrs but it doesn't work with my schedule

thx

 

[GMBoy]

You do want to be careful changing plugs on a hot engine due to the threads and that is why cool engine is recommended to do the work on. With that being said - letting a vehicle cool down enough that you can safely work on it without hurting yourself is enough time to wait. I usually give an hour or 2.

 

[TomYoung]

Then don't do it in the morning, do it when the car is cool.

 

[slacktide_bitog]

At least 2 hours

 

[JavierH19]

Aluminum threads can be damaged more easily when hot so yes do it when it's cold and that'll take a few hours at least. Remove the engine cover and coils if you want to speed it up some. Do it at night or some other time when your schedule allows even if it's much later. Plugs aren't critical unless they're so worn out they're definitely causing a misfire.

 

[Passport1]

Fifteen minutes per the number of cylinders.

 

[RooflessVW]

Just let it sit for an hour or so.

You guys think shops are letting these things cool overnight for plugs?

Rack it, do everything else on the ticket first, change the plugs, send it.

 

[I<3oil]

4.3 days

 

[Blueshound]

It really doesn't make much difference except for comfort.

75 degrees sounds wonderful btw! Haven't seen that on the thermometer since last September....

 

[4WD]

You do want to be careful changing plugs on a hot engine due to the threads and that is why cool engine is recommended to do the work on. With that being said - letting a vehicle cool down enough that you can safely work on it without hurting yourself is enough time to wait. I usually give an hour or 2.

Then there is the proximity of the exhaust manifold

 

[The Critic]

Just let it sit for an hour or so.

You guys think shops are letting these things cool overnight for plugs?

Rack it, do everything else on the ticket first, change the plugs, send it.

Same with Valve Adjustments. No one waits, pull it into your stall and get it done.

 

[The motor guy]

I think it takes a whole day to cool back down. My cummins takes a while to warm up if it hasn't been driven for a few days, compared to me firing it up the next morning after parking it for the night.

 

[vavavroom]

I want the engine cool enough to not get more than first-degree burns while working on it.

 

[JohnnyG]

2.3 hours, unless you point a box fan blowing into the radiator. That will cut the time down to 1.5 hours, unless the ambient temperature of you garage is above 90˚F. If that is the case it will take more like 2 hours again.
Don't ask me how I know this.

 

[atikovi]

i know tons of answers will be regarding to just do the plugs in the morning after its off for a few hrs but it doesn't work with my schedule

You work 7 days a week?

 

[nate379]

Just let it sit for an hour or so.

You guys think shops are letting these things cool overnight for plugs?

Rack it, do everything else on the ticket first, change the plugs, send it.

I hated working at Sears on cars that somehow had the engine hotter than molten steel.
Still have scars from flesh cooked off on them.

 

[meep]

Putting a fan on it speeds the process surprisingly

 

[The motor guy]

I hated working at Sears on cars that somehow had the engine hotter than molten steel.
Still have scars from flesh cooked off on them.

Yep. Burned my arm on a mower muffler that ran all of 5 seconds when I realized the height needed to be adjusted. Big fluid filled blister that popped one day in science class all over the desk. Lol

 

[apollo18]

darn 2 hrs would make it hard for me to time it perfectly. if i use a very large fan aimed at engine area, any way i can get it down to be cool enough in 30 mins? even with hood wide open in shaded area? 2 hrs seems high but i trust everyones experience since i havent really had experience

 

[The motor guy]

Sometimes you have to do things at 2am If that's what it takes.