Can I run engine for a couple of minutes without coolant?

[novemberr]

Hello,
For my 1991 Camry, it is recommended to run engine to push the rest coolant from engine block after drain coolant. Can I do the same on our trucks?

 

[Doubeleive]

I wouldn't for more than a few seconds, that's playing with bad news real fast

 

[kwOH]

Sounds sketchy to me.......

 

[inmypassatlife]

In order for it to even come up to operating temperature, it will take more than a min. In fact, the coolant doesnt' serve much purpose until the thermostat opens and it takes a little while for it to open and circulate coolant. If the coolant is not circulating, the only thing the coolant will do for the motor is to absorb the heat up the the volume in the block times the specific heat capacity of coolant, which is very little.

I would run it for about 15-30 seconds to be safe though

 

[Doubeleive]

it's not like running an engine without oil but it will get hot pretty quick, I have started mine up before for a few seconds to push out old coolant when switching from dexcool to the green stuff, but I wouldn't do it for more than what's absolutely necessary.

 

[PG01]

Personally if you really think about, you can run it for a minute...takes at least that long for thermostat to open. If you guys start your car truck see how long it takes for your temp gauge to move...at minimum its a minute.

 

[kbuskill]

Probably best to drain it after its warmed up a bit.. that way thermostat is already open.

 

[Doubeleive]

what I usually do is drain it, fill it with water, run it for a little bit, drain it, fill it with water again, run, drain again, usually after the second time around it is looking like mostly just water. then throw some chemical cleaner in there and run for 10 minutes, drain/run a couple more times then add fresh coolant. a little tedious but good for California cars

 

[2011SSVHOE]

I used to undo the upper radiator hose at the radiator.
Take a water hose and run it slowly into the top of the radiator where the cap goes. until the t/stat opens watch the coolant come out of the top of the radiator at the hose outlet until it is clear. shut engine off and drain the radiator, reattach the hose and refill with the proper coolant/water mix and you are done.

 

[73shark]

Unfortunately most car manufacturers in their infinite wisdom moved the radiator cap to the coolant overflow tank which makes it difficult to do what you suggested. You can then I guess stick the hose in the open upper radiator fitting in place of the radiator cap fitting.