Car Overheating, Please Help, At work

[Dailydrive]

Here I am again. I have had no problems with this car for 200 miles since I fixed everything. I still have dye in the coolant, which has been diluted significantly. So, it is more like 10-20% coolant at this time. I had a leak but the leak is gone and I was going to change it back to 50-50 dexcool after work today. On the way to work today everything was fine I went 15 miles with and obd2 attached, and I was at 219f - 221f the whole time with the a/c on and the fan going( I could hear it and I know it works). All the sudden I pretty quickly shot up to 240 degrees, not seeing this before i shut of the engine and pulled over. Check for the leak I had previously had but there was nothing. I was not losing coolant and am still not. So, I got back in and started driving again. had no problems for a couple more miles. Then it started again this time I was curious how far it would go so I let it get to 250. A boiling kinda noise started, I had my heator core open a little so I think the sound was coming from it. I immediatly shut off the car. Once it was at 225 or so I tried again(still no leak btw). Again it evened out to 219-221 and I was off. Then again it shot up so this time I gave it gas in hopes that the water pump would circulate the water better and it continued to climb. I don't know why I did this next thing but I shut the car off and immediatly started again and gave it gas. The coolant temp went back down to 219. I am confused as to what is happening to my car. I have a 35 mile ride home today. Like I said I have been driving the car leak free for 200 miles and it has never gotten to more than 230f before this. It usually sat a couple clicks above the center (219F). I am really worried about my drive home. Any suggestions? Is it the fact it is more water than coolant? I wouldn't think that would matter. Thanks yet again.

[dbsanfte]

Your antifreeze concentration is so low that the coolant has started boiling in the head. Get it back to a proper 50/50 mix.

[Dailydrive]

Wow. Really? I ran it like this for 200 miles. I know nothing so please don't take my question offensively.

[Dailydrive]

So I should have been running at 195F while driving down the highway?

[dbsanfte]

Ideally yes. The thermostat will open around 190 and the rad flow will keep the temp stable around 195. The thing is, antifreeze doesn't just prevent freezing, it also prevents boiling. Without enough antifreeze your coolant is boiling and the steam pockets are spiking the temp gauge.

Never run less than a 50/50 mix...and don't drive that car until you fix this, or else your head gasket is in danger. You can drive it briefly while cold but not longer than a few minutes.

[Dailydrive]

Ok. Thanks.

[dbsanfte]

To just get the car home, drain a gallon of coolant and replace with a gallon of -straight- antifreeze (not mix).

When you get home I would drain the coolant entirely, flush the system, then dump in a gallon of straight universal antifreeze, and top it off with distilled water, just until the coolant level reaches the seam in the tank.

[Dailydrive]

Ok thats what I will try. Now I just have to find an environmentally safe place to do that.

[Dailydrive]

Whats the best flusher/cleaner to use?

[lil_buddy]

Do you pay for roadside assistance every month?
If no, what are u crazy?
If yes, just have them tow the car to your house.

[OldNuc]

Just flush it out with clean water and then when you refill it use a full gallon of 100% antifreeze and top off with distilled water. The reason you are having trouble is the low concentration of antifreeze. Check that there is a solid stream of water returning to the reservoir from the small line attached to the right rear. Verify the small line clamps are tight. If that line is plugged you are going to be boiling over a lot.