What is too hot with respect to coolant

[MCH86GN]

I was swapping out RMI and water for coolant/antifreeze yesterday and during this time my engine coolant temperature went to 225*. I have put 2 gallons of coolant in the car and I didn't realize my fan wasn't plugged. I plugged it in and the coolant was circulating, but the temperature kept creeping up. So I decided to shut the engine off, the reason I figured it wasn't cooling enough is that I needed coolant. I'm sure once I shutdown the car the temperature rose a little more I'm sure to around 230*. Just wondered it this temperature could warp the aluminum heads? I had my wife pick up another gallon of coolant and I went out and started my car again about an hour later and the coolant temperature was down to 134. So I started to the car to let the coolant get circulating again and this time I couldn't get the car to go above 170* despite the fact that I had not adding any coolant. So I had to unplug the fan again to get the coolant flowing and then I added about a 1/4 of a gallon and the damn thing was full. I plugged the fan back in at let the car run again and it was staying in the 160s. I got scared when the car hit 224, so I turned it off. I probably should've kept it running and the temperature would've went down, but I wasn't sure and I didn't want to ruin my new build.
Just wondering what temperatures it takes to warp the heads. The head on my Cruze is aluminum and the base operating temperature is 224*. The aluminum head on my Cruze is probably made of a different grade of aluminum.
Thanks.
Anybody ever warp aluminum GN1's

 

[dank GN]

. I believe the factory had a 190* thermostat in there . I shut my car off if I see it get much past 220 . Sounds like you have a leak down test in your future .

 

[MCH86GN]

. I believe the factory had a 190* thermostat in there . I shut my car off if I see it get much past 220 . Sounds like you have a leak down test in your future .

I had shut it off and started again it didn't get above 170, even though I hadn't topped of the coolant. My guess if I had let it keep running with the fan on the temperature would've probably drop. As I started, after it cool down and I started it again with same amount of coolant as before, as soon as it hit 170 fan on temps went down to 162. Remember, the initial start when I was adding coolant was a cold start, so engine oil hadn't probably warmed up to the same temp as the coolant. Once I poured about a gallon and and a half, I couldn't get anymore coolant in it and I had to put the radiator cap on it to keep it from coming out. Finally it started circulating and I was able to finish pouring the remainder of the second gallon in. Temps keep raising and at 190* I plugged the fan in, but the temperature kept climbing until it hit 224* and figured it was time to shut it down until I got another 1/4 of a gallon of coolant. I'll probably still do a compression test though. Like said though, my Cruze's normal operating temperate in 224*. Just to be safe I'll get a compression check down.

 

[dank GN]

I just had this same situation yesterday. The thermostat didn't open completely so it didn't allow the coolant to completely fill the block and heads and at the same time the trapping pockets of air . My temp went all the way up to 200 . I then dropped to 160ish and is running normally now . am runing a 160* thermostat with 4x 1/8" holes drilled in body

 

[MCH86GN]

I just had this same situation yesterday. The thermostat didn't open completely so it didn't allow the coolant to completely fill the block and heads and at the same time the trapping pockets of air . My temp went all the way up to 200 . I then dropped to 160ish and is running normally now . am runing a 160* thermostat with 4x 1/8" holes drilled in body

My engine is brand new. I certainly hope the heads weren't damaged. 200 isn't actually all that high, unless you are getting ready to run. With the 93 octane fuel the higher the operating temperature the better burn you get on the fuel, since 93 takes longer to burn at a given temperature than say 87.

So far nothing leaking on my car, no oil coolant mix in the oil pan or vice versa. Definitely run it by my engine builder though.

 

[mikestertwo]

Your ok. I had an engine go to 240* with no issues (bad thermostat). You didn't run it for any extended period of time so the engine should be ok. I have seen engines go even hotter with no long term effects.

 

[MCH86GN]

Your ok. I had an engine go to 240* with no issues (bad thermostat). You didn't run it for any extended period of time so the engine should be ok. I have seen engines go even hotter with no long term effects.

Wanted to make sure because of the aluminum heads. However, I understand they warp when there is an extreme temperature differential between two areas. Probably had an air pocket. Once it cooler off and I had additional coolant, it started right up and then as I mentioned I couldn't get the temperature to go above 170*, even without the additional coolant to top it off.


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[INEEDAGN]

Friend has an aluminum headed 4.1 that hit 248 on the scanmaster due to fried relay pins in the fan hotwire harness. Never tore it down to check afterward (to my knowledge) but no apparent damage from it.

 

[Wahoo]

Did you try squeezing the radiator hoses to try to burp the air out of the lines/engine?

 

[MCH86GN]

Did you try squeezing the radiator hoses to try to burp the air out of the lines/engine?

Nope. However, I drove the car today didn't seem to be any issues. Did a couple of burnouts, again checked the oil for coolant and coolant for all is good. Ambient conditions, it was cold when I started the car, coolant might have gotten hot but oil was still cool. Car wasn't runing for more than 10 mins. I think everything will be alright. I'm a little paranoid because I just spent $15k on rebuilding the motor and trans, would hate to ruin anything.

 

[DCG]

You are supposed to leave the radiator cap of when you are filling the system to bleed out air. Run it until the t Stat opens and the upper hose is hot. Have your heat on hot to bleed out the heater core. When you see no more air bubbles in the radiator, top of coolant and put the cap on.

 

[earlbrown]

Sounds like you were getting a false reading from steam hitting the sending unit not coolant.

Anytime you're messing with the cooling system make sure there's a steam hole at 12:00 on the thermostat and that the heater is set to 'hot'. It takes a few heat cycles to completely burp the system even when everything is right.

 

[robertf]

Best coolant ever. A tad pricey but you only buy it once, period.

 

[Nick Micale]

One major fact is that water will run cooler than "coolant" because it will transfer heat better than most any fluid, especially antifreeze [and Evans].

What will be a substantial help is to add RMI-25 when using antifreeze as one of the elements it contains is a chemical which breaks down surface tension between the fluid and metal for better heat transfer.

For $10 you can get the best best treatment for your cooling system as RMI-255 also contains other essential additives for protection as well.

 

[robertf]

Nick can I add RMI to the Evans?

 

[87GNSteve]

When ever I start a new build, or major overhaul I keep a water hose close by. I had failed fans and it got real hot, I just sprayed the radiator down and completed break in.
Plus I thought a water hose would be good if a fire broke out. The way things go for me anything can happen.

 

[No disintegrations]

When ever I start a new build, or major overhaul I keep a water hose close by. I had failed fans and it got real hot, I just sprayed the radiator down and completed break in.
Plus I thought a water hose would be good if a fire broke out. The way things go for me anything can happen.

Just don't use water if it's an oil or gas fire. The fire will float on the water and could easily spread to another car or house or your feet.

 

[MCH86GN]

One major fact is that water will run cooler than "coolant" because it will transfer heat better than most any fluid, especially antifreeze [and Evans].

What will be a substantial help is to add RMI-25 when using antifreeze as one of the elements it contains is a chemical which breaks down surface tension between the fluid and metal for better heat transfer.

For $10 you can get the best best treatment for your cooling system as RMI-255 also contains other essential additives for protection as well.

Initially when my motor was put it my builder put water and RMI-25. Since I live in MI, I had to switch over before we get below freezing temps. I will definitely put RMI-25 with the coolant. I really wish I didn't have to use antifreeze at all but I don't have heated garage. If it were practical I would swap out the antifreeze/coolant for water and RMI-25 every summer. It would certainly keep my coolant system flushed. I'll PM you about the RMI-25.


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[87GNSteve]

Just don't use water if it's an oil or gas fire. The fire will float on the water and could easily spread to another car or house or your feet.

In an emergency water will work fine.