Trying to use a blown head gasket tube tester. I opened the radiator cap, started the car for 15 minutes, put the heater on and extracted a whole water bottle of coolant from radiator cap because it kept rising out of the radiator cap tube. I extracted all the coolant again and inserted the tube (thinking it might create a seal and stop the coolant from rising) and started suction but it just filled with coolant. Coolant just keeps rising out of the radiator cap.
Am I doing something wrong? Can’t I just keep radiator cap on and use the coolant reservoir to test?
If you have exhaust gases blowing into the cooling system from a bad head gasket it can certainly keep blowing coolant out of the radiator.
You won’t even need the tester for this - install the radiator cap, run the engine and watch the overflow reservoir. Does it look like it’s boiling or something like that? If yes, exhaust is blowing past your head gasket into the cooling jackets.
If coolant is coming up and out before the engine is warmed up, it sounds like you have a blown head gasket… Without knowing if it is circulating before it blows out, it is hard to say, not sure if your T-stat is stuck closed or not…
At what temp does it start blowing out the rad??
And NO, the coolant can not contaminate the block test fluid…
The coolant was at the rim under the radiator cap when I took it off when cold, (reservoir coolant was low) I then siphoned it out of radiator cap(not a lot as it is a double L shaped or curved plastic tube, it’s not straight down.) Then I started the car and the coolant slowly started to come out of the radiator cap opening. It’s not shooting out, it’s just gradually coming out.
It’s slowly but constantly coming out of the radiator cap opening when running. Have not tried if it does it when shut off.
I’ve noticed the reservoir has been low and figured since I have the tester to just check it. I tested the reservoir and it stayed blue, I then put it to the exhaust tips and it turned yellow right away. I do not notice the coolant in reservoir boiling but it just smells really hot.
Of the car??? You can cup your hand around it and breath into the tester and turn it right away also… Hint: if you take it out to open air and squeeze the bulb multiple times it will turn back blue and can be reused, as long as no coolant has contaminated it…
Only if exhaust gasses make there way up to it, but probably not… Use a scanner to see the temp when the coolant starts to push out the rad, if hot enough, it will do that normally, that is why you put a rad cap on the system to hold pressure and raise the boiling point…
In other words, no on can tell what you’re saying. You decided to check for a head leak because the reservoir was low? But the radiator was full. You pulled some coolant out and started the car and some coolant came out. Is that the whole thing? Nothing weird there. If the reservoir is consistently low, the just look for normal leaks. There’s no need to think head gasket.
Coolant expands when it gets hot. So it will come up out of the radiator cap if left off. If the radiator cap is on and good, then it will go to the overflow as it should. Is that the question?
If you just want to use the tester for exhaust gas test (probably not needed), then you need to pull more coolant from the radiator.
Well do as the others are suggesting. Why do you think you have a gasket failure.
Not to lead you down the wrong path but when I had head gasket problems, I would get wide swings on the temp gauge. Spike hot then cool once the car was moving. I would see bubbles in the radiator signifying gases in the coolant. At the end, I drove the last 30 miles with the cap loose or off to release pressure.
There are other symptoms but you are looking for the presence of gases in the coolant.
That’s normal. The coolant volume expands as it heats up, plus it might boil a little as the block heats, and the extra volume has to go somewhere, so it goes out the top of the radiator. When the radiator cap is on it pressurizes the coolant, preventing it from boiling, expanding, & overflowing.
The way I solve this problem when I’m flushing the cooling system in my cars is to remove the hose from the top of the radiator and run it (via extension hoses) into a bucket. As the coolant heats up the thermostat opens and hot coolant then flows into the bucket rather than overflowing the radiator.
Note: This may or may not work or be advisable w/your particular car’s cooling system. Every car is different.
Yeah but just remove the thermostat and you can flush the engine directly. Then the radiator, then the heater core. But you need a hose adaptor. Use various sizes of pvc pipe and a plastic watering nozzle glued together.
Ok, makes sense. Was not sure because the instructions nor any of the videos of people doing the test ever mention coolant constantly coming up out the radiator cap.