TheCooler

Can you run the car without coolant for a minute to check to see if it runs?

2BWise

You can, its not necessarily a good idea. Just make sure its not long (in the seconds range).

TheCooler

Alright ...I just wanted to make sure that it would actually run without coolant in it. I want to make sure my wiring is correct before i put the whole car back together.

2BWise

Understandable...its a pain to put it back together just to have to take it all back apart. Done that too many times

xsboost90

wont hurt it unless you over heat it....could be hard on the wp seals but not too bad.

TheCooler

I just replaced everything in the front ....New waterpump also...

Z-man

I wouldn't. Just fill up the system with H2O. So if it doesn't run, you have to drain all the water - no big deal, and that's far less of an issue than hurting something.

-Z.

Legoland951

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 seconds as you will have a good idea by then whether your car is running right.

MM951

Yes, I've done it before with no ill effects on past cars for the same reason.. Just ran it 10-15 sec ..

genikz

Hell, I did it the other night with no heater core, drained coolant, no dash, no guages, the car on jack stands and jumper cables attached to the battery leads.

Aside from scaring the crap out of me when the box fan I had in the car fell over as I fired it up, no ill effects what so ever. I did 2-3 seconds though, just in case it does damage the water pump in the long run (ie coolant = lubricant?)

Serge944

Don't do it more than a few seconds. You have to realize that even though coolant isnt moving due to a closed thermostat, it acts as a huge heat sink since it has a much higher specific heat than aluminum!

MyBlackCar

Use water. The heat, no matter how short of a period of time, will have no place to go but to the block. Not worth the chance that you will damage your block.

Laust Pedersen

True, by a 5:1 ratio, but easily outweighed (pun intended) by the aluminum to water mass ratio.

I have done it with no side-effects on a number of aluminum engines using the “touch and feel method”: Touch the block (or cam tower in this case) and if feels uncomfortably warm stop the engine.

However I would be a little cautious putting a high load on the engine without water, since it could generate too much of a thermal gradient (bad for thermal stresses).

If the engine has been drained within the last weeks, then there should be enough moisture left to lubricate the WP seal for the duration.

Laust

Bill

You should be able to do it for a short period. I would say no longer than a minute. In my younger days I threw a belt on a VW beetle engine (generator light goes on when this occurs). I was on the freeway and was trying to get to the next exit that was in my vision. I figured "air cooled block", plenty of air flow. The pistons seized no more than 2 minutes later. Heads cracked.

Legoland951

Laust is right. The engine can only be hurt if the thermal gradient is high enough (you probably would have to floor the car towing a 10k pound trailer and hit the nitrous for 15 seconds for that to happen). This thread is reminding me of thermodynamics and Bournelli's equation which brings back memories of pain...