jeremyb

I've had my car in my garage for about 3 days now just sitting there completely cold. So I expected to add coolant (bad coolant seals).**Just for documentation I have eliminated my AST** So I go and turn my filler neck cap and remove it.. and a bit of coolant bursts out and my cap neck was full. I was like WTF?! . Every morning I always add a bit off coolant and top my filler cap neck off. Ok, I started my car JUST to move it over one car space in the garage. Meaning the car was only on like 2 minutes MAX. This whole incident was 2 days ago. So this morning I go to pop my cap open again and coolant bursts out as if my engine was warm and has left over pressure. With a car sitting for so long, being so cold...would anyone know why it kept under that much pressure for so long? My filler cap neck is at .9 bar or 13psi I believe and there are no restrictions in the spring for the cap. The overflow tube is also clear of flow. I know its perfect if you pop you cap and you have coolant about an inch or two from the tip of the cap neck with a cold motor, but to have it sitting there for 3 days and bad coolant seals, how the HELLLL does it sit with so much pressure sustained in the system? Anyone experience this before? Causes? Solutions? Advice? Thanks in advance.

Jeremy

Gadd

How do you know your seal is bad? "perfect" is the coolant will be right to the top of the filler neck. That means all the air is out of the system and it is drawing coolant back from the overflow when the motor cools just like it should. As far as pressure in the system when the car is stone cold, If it was cold at night and you are opening the system when it has warmed up during the day, it's possable to have a little pressure in the system.

DamonB

If the coolant seals are bad then the engine itself pressurizes the coolant system. Apparently the pressure is not enough to vent out of the cap, but it is enough to puke water on you when you open the cap.

Gadd

So just to be clear, did you start the car this morning before you opened the cap? If you didn't start the car, I don't see how the system would hold pressure for two days with a bad seal.

DaveW

O-rings are funny sometimes - they will sometimes seal pressure in only one direction, or sometimes seal only if warm, etc.

So if enough combustion gasses entered the cooling system to have a significant volume to maintain pressure cool, pressure COULD remain in the system for quite a while.

Gadd

Hmmm.... Those silly O-rings.

AntiVenom7

the cap you are using could be too high of a pressure? just a thought.

jeremyb

Crazy white smoke at start-ups. I add coolant every morning. Sometimes I can't even start my car cause it gets flooded.

But if the seals were bad, wouldn't coolant also go back through the seals after the car turns off causing the failure of thermosuction that a car with good seals would do?

I didn't start the car before I opened the cap. I always expect to add a bit of coolant into the filler neck every morning before I start the car. The car has been sitting for 3 days before I popped this cap. That is why I'm so puzzled on how the pressure held for so long. Then after I turned the car off (after moving the car), the car sat for another 2 days untouched. I popped the cap to add coolant and coolant bursts out.

Those were one of my theories at first but it just weirded me out so much that I had to see if anyone else has experienced this. But for sitting for 3 days... then another 2 after a 2 minute run... how the hell does it hold for so long? I've never had any pressure hold for so long EVER... since I've had my car.

The cap is .9 bar or 13 psi. That's to what I believe is what the cap should be with an eliminated AST.

Jeremy

mad_7tist

so you know you have a blown coolant seal and you are trying to diagnose a coolant prob/issue?????

jeremyb

Yes, I have a bad coolant seal. I'm talking about the pressure problem. I know the seals can cause this... but im being ignorant... my car was long cold... sooooooo did anyone else experience this?

Jeremy