Coolant Bubbling when car off.
 

I did the linear water gauge temp mod and everything works fine.

My cooling system is working fine when the car runs but when I stop and let the car cool down it bubbles. I am using a 13 psi cap. Should I use a 16 psi?

Also, my fans work when the temp gets hot but once the car shuts down it doesn't keep the fans on. It only stayed on one time properly. Relay problem? Where should I look?

your system is not full. u remove the ast?
basically you will have to fill up everyday alittle bit b4 u leave. it should stop bubling.

your fans only come on if the radiator is hot. they dont always come on.

Try using this stuff its called Evans Coolant, Its great stuff, it totally replaces coolant and water so you just run straight Evans coolant, it doesnt boil, steam or expand at all, you can run your car all day, pull over and pop the hood and take the coolant filler cap off and it wont explode, you can just watch it pump through because it doesnt expand like water or regular coolant does.
Also it doesnt bubble like water will create bubble on the coolant passage walls so you get the coolant actually making full contact with the metal and thus cools much better...
JDub

It's pretty full...all the air is purged out too. I'm scared that it's overheating when I let the car rest. Any other suggestions?

Bubbling also occure as the turbos are cooling off and dumping heat into the coolant (don'tforget we are running coolant THROUGH the stock twins). A slight slurping sound is pretty normal. A percolating loud bubbling sound is air in the system as potato mentioned.

AST was put in there to take care of this. Evans is a great way to go.

first of all, do the fan mod where you can keep the fans on after you turn off the car and/or when you are driving around in traffic or what ever. Secondly, are you popping your hood to cool your car down a bit when you shut down after a hard run?
lastly, stick with the 13psi cap, the 16psi one is too much.

good luck

P.S. if you turn your car to heater or a/c on, the fans will come on as well

The UIM will always feel hotter a few minutes after you shut down...

I remember having that bubbling for a week straight, and then it started bubbling and dumping coolant outta the overflow tank a week later. I replaced my ast and both caps (13 psi) and the problem went away. The cap on the ast was my problem.

What's the AST? I've already changed the 13psi cap (tested and holds around 12-13psi).

Also, with Evans how many gallons should I get? Is it lubricating to keep the waterpump lubed? Is it safe, non-corrosive?

AST is the air separation tank. If you have the stock intercooler it should be mounted on the right backhand side. It also has a radiator type cap on it. If you have one you can't miss it.

water does not expand or contract to any appreciable extent in response to temperature or pressure. check your high school or college physics textbook, im pretty sure this is the case.

this would be my first post here... hhmm... water does not expand very good point! You oughta be checking your chemistry textbook for pv=nRT.. ;) adding impurity/solute to pure H20 alters the boiling point(rises) and the freezing point(lowers) of the water but certain parts of the engine get hot enough to boil the coolant with higher boiling point and that creates the pressure within the cooling system.

I'm told Evans coolant runs 10 degrees hotter than regular antifreeze/water mixture. Evans is cool because of the ability to not boil over.......

I use the redline water wetter. That seems to help out.

Mine did that when I bought my car for like 3 months. When I replaced the cap with a new one, it stopped perculating.

how do you get the fans to keep running when the car is shut off?

thanks mahjiik