boiling sound?

[RS12Turbo]

Recently when I shut off the engine after driving, I can hear a boiling sound coming from what sounds like to be within the head, but I'm not 100% sure.I've never noticed this before, and seems like when I did notice it, was after I drained the coolant and replaced it with a 30% coolant, 70% water/Redline Water Wetter mix, which was about 2 months ago. My t-stat has a jiggle valve, so I don't think there is air trapped in......and the car seems to be running normal as usual.Any ideas? Could there be air trapped in the system even know there is a jiggle valve, or could there be a bigger problem?

[syphrus]

Did you inspect to see it was sounding from the head. I used to get that noise... was coolant draining/bubling into reservoire.. dunno though.

[RS12Turbo]

I only put my ear over the valve cover area.....and sounds like it's from that area vs the front of the car where the resivor is at......I'll listen for it up there this weekend, and see if it is coming from the resivor

[themadscientist]

top off the cooling system and bleed the air out. The radiator cap is not always the high point.

[RS12Turbo]

top off the cooling system and bleed the air out. The radiator cap is not always the high point.

Dumb question.........but how do you bleed the system? Take the rad cap off, and squeeze the top rad hose, and see if bubbles emerge? Also, isn't that the jiggle valve's job?Oh, and the radiator is full to the rim with coolant

[The_Chosen_One]

I had a similar situation, it was coming from the turbo coolant line that goes to the intake manifold, I believe it was air escaping.

Eventually it went away, I assume it was air escaping.

[themadscientist]

take look at all the water hoses. You have the S12 CA with the crossover manifold right? If so there is likely water lines running through the throttlebody that are higher than the radiator. The RB20 is the same. Look for a bleeder screw at a high point on the engine.

[RS12Turbo]

No............it's a s13 ca-det. The ca-et is long gone .Is there such a bleeder screw on the ca-det?

[r34 gtr]

No, just do what you said and squeeze the top radiator tube. Sometimes my car makes gurgling noises after I shut it off because of the coolant circulating around the heater core junk. Never gives me a problem, it just sounds like my stomach does right now.

[mbmbmb23]

Also try putting the front of your car on ramps or jack stands to get the front raised up, I know this helps bleed SR's. You could always take it to a shop and have them pressure flush/fill the system to ensure all bubbles are out. I didnt get all the air out when I did my KA before and it ended up boiling a hole in the corner of my plastic radiator end tank. I'm thinking the thermostat housing wasnt sealing properly due to one bolt head that was broken off (and JB welded) but....anyways.....a service tech can pressure test your coolant system them pressure fill it completely.

-m

[RS12Turbo]

I think I took care of it.......I burped the upper rad. hose several times, with the cap off, and lots of big bubbles came out. Thanks everyone for your input