Does Coolant Evaporate Over Time?

[AtoyotA]

I replaced my radiator with an OEM one and filled it with toyota red (and distilled water), all the way to the full line on the overflow.

I also replaced the upper and lower rad hoses as well as a couple other odd hoses - all with new clamps to boot.

I just drove about 3k miles over the holidays and now the overflow is no longer at full, but maybe 1/8" below it. does coolant naturally evaporate over time or could i potentially have a head gasket problem?

 

[CJF]

1) You sure it didn't just drop the first or second day after the work done due to air in the system?

2) Eighth of an inch ain't much. Just mark the level of refill and keep an eye on it.

 

[AtoyotA]

1) You sure it didn't just drop the first or second day after the work done due to air in the system?

2) Eighth of an inch ain't much. Just mark the level of refill and keep an eye on it.

im pretty sure there was no air in the system bc i used a venturi refill kit and then i burped it afterwards for good measure. there is definitely some missing coolant, but you're right, it ain't much!

 

[Mike NXP]

im pretty sure there was no air in the system bc i used a venturi refill kit and then i burped it afterwards for good measure. there is definitely some missing coolant, but you're right, it ain't much!

Outside air temperature is a factor of where your coolant will sit in the reservoir . Colder weather = lower level in res. Hotter temps = higher level in res

I don't know what a venturi refill kit is but you still could have ended up with some air in the system after your system was refilled. Sometimes it takes a few heat cycles.

You almost certainly don't have any concerns with a head gasket unless you ; overheated, continue to lose coolant, are blowing smoke out of exhaust. Keep monitoring the level and keep it above half in the reservoir but Im sure you are good to go

 

[AtoyotA]

Outside air temperature is a factor of where your coolant will sit in the reservoir . Colder weather = lower level in res. Hotter temps = higher level in res

I don't know what a venturi refill kit is but you still could have ended up with some air in the system after your system was refilled. Sometimes it takes a few heat cycles.

You almost certainly don't have any concerns with a head gasket unless you ; overheated, continue to lose coolant, are blowing smoke out of exhaust. Keep monitoring the level and keep it above half in the reservoir but Im sure you are good to go

by venturi refill kit i meant putting the cooling system under vacuum and then replacing the vacuum with coolant. what you said about OAT makes sense.

the only reason i am even considering the head gasket is bc when i replaced my t-belt 3 years ago, i had a hose blow off the radiator when i was on the highway. I probably drove for another 10 seconds at 70 mph+ before realizing what happened, and then i drove another 30 seconds - without coolant circulating - in order to get to the walmart parking lot (but at least most of that was at highway speed so there was air cooling).

i havent had any issues since i fixed the hose those years ago, but it's always been in the back of my head that i did some damage when the engine got that hot.

 

[rexington14]

by venturi refill kit i meant putting the cooling system under vacuum and then replacing the vacuum with coolant. what you said about OAT makes sense.

the only reason i am even considering the head gasket is bc when i replaced my t-belt 3 years ago, i had a hose blow off the radiator when i was on the highway. I probably drove for another 10 seconds at 70 mph+ before realizing what happened, and then i drove another 30 seconds - without coolant circulating - in order to get to the walmart parking lot (but at least most of that was at highway speed so there was air cooling).

i havent had any issues since i fixed the hose those years ago, but it's always been in the back of my head that i did some damage when the engine got that hot.

I think the 4.7L is stouter than you think. Overbuilt, cast iron block and all that. Overheating is never good, but unless these are severely overheated with immediate apparent damage / effects or blatantly obvious coolant loss I wouldn't worry about it. You could always get a UOA done to check for traces of coolant in the oil for some additional peace of mind.