Car puking coolant

[Pedigry]

Hey guys,

Ran the car 1000 miles this past weekend. Car ran well but is puking coolant everywhere out of the overflow tank. When I'm on the highway, the temp starts at about 175, then slowly climbs to 190 or so as the coolant is emptying out of the rad. When I get off the highway and slow down (reducing cooling over the rad), the temp quickly starts to rise. I then stop, put more water in the rad and the whole process starts over again.

I changed the cap last week thinking that was the problem but it didn't fix it. I am afraid the system is getting pressurized by a bad head gasket. The engine runs great and I don't see any white smole out of the exhaust, but something is pressuring the system and I am not sure what.

Would getting the system pressure tested help?

Any ideas?

[Pedigry]

OK, so I called a local rad company and they gave me an idea i thought i would share. He said to fill the rad up with water completely. Then roll the motor over, if it bubbles or pushes water out of the top then its a blown head gasket. Here's to hoping it's not. I will check it when I get home.

[dhutton]

I think you are most likely overfilling your radiator. Only fill it to when the tubes are covered. Don't fill it right to the top….

[oakhill510]

Did you check to see where your dad coolant level is at after it puked put coolant? Like somebody mentioned, could be over filled.

Did you fill radiator and coolant overflow at the same time when you topped off?

[Pedigry]

No, I'm not overfilling it. Because when I get off the highway the temp goes straight up to 215, it didn't used to do that. When I stop, I am putting in 2 large bottles of drinking water and it still doesn't go to the top. It's puking 1/2 the radiator out.

[dhutton]

Did you burp it when you initially filled it? If not, burp it.

[Pedigry]

I didn't do the initial fill but thats a good idea, I'll burp it tonight.

[Vimes]

If the problem persists after you've done the easy stuff, do a cylinder leakdown test. It'll let you know if there is a head gasket problem and what cylinder it's on.

[Pedigry]

Yeah, I thought about doing a quick compression test. Figured if it's a leak, it will show up on one cylinder. There is also a gasket tester that you can put on the raidiator and pull air through it, it will change color and show whether it has combustion gasses in the coolant. It's called "block tester". I'm going to see if the local auto parts store has one for rent.

[Hotwire]

what type of fan are you running? Mechanical, electrical? Are they working? Have you done anything to the way air is flowing into/through the rad? Done anything in the engine bay that would change air flow characteristics or block air from exiting?

[Pedigry]

After spending some time with the car this weekend I found two small holes in the rad. That was the culprit. Now I just have to find someone that can drain and pressure test to see if it's fixable or if I have to order a new one. At least I found the leak.

[Vimes]

Glad you found the problem. However, it's rare these days that fixing a radiator is cost effective. If it was caused by corrosion, the entire inside of the radiator will have similar corrosion and will just develop new leaks in a short amount of time. If getting the core replaced, unless you have metal endcaps you now have old plastic on new metal, and the repair will likely cost as much as a new one so it's best to just replace it. Not to mention, you'll spend the next year worrying about it if you try a repair.