Cooling issue. HELP!

Im currently having cooling issue with my 06 sti which when I go full boost my temp goes up, my coolant overflow fills up and the coolant spills out! Maybe there is some air stuck into the system or head gasket (please NO). Im curently using peak 50/50 coolant. Any help will be appriciated, HELP!

Current setup:
Mishimoto X-line radiator
Mishimoto Expansion tank
Mishimoto 1.3 bar radiator caps
Subaru OEM thermostat

I'd look into getting a special coolant funnel. They have the specific caps you need and it will ensure you get the air out of the system. Make sure on a cold start beforehand check and top off all fluids in radiator and overflow and the reservoir. Then turn heat to high, then fill funnel attached to RADIATOR, and start the car till the fans kick on, then shut the car off and put your cap on the radiator and let it cool down completely cold, then top off the reservoir, and your good to go. Make sure you squeeze the top radiator hose because it being horizontal air gets stuck in the hose. Then you should be okay. Make sure to double and triple check the coolant in the RESERVOIR, and top off in the reservoir. Don't reopen your radiator cap because that little bit of pressure, because the radiator sits lower than the reservoir the coolant will leak out. It's full on that point. And triple check your over flow and make sure the hose inside the overflow is always submerged underneath coolant or else you will suck air into the system that way as well. Never let overflows run dry. that's all I can think of and if that doesn't solve your issue then I'd pull the thermostat before thinking the worst. Always try the easy stuff first before you have to stress over head gaskets. I hope the best for you.



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head gasket problems are the best! what you described is exactly what happens when you leaking compression into your cooling system. you can order a kit off amazon that lets you test for head gasket issues just to make sure before you pull the engine out and do the work or take it to a shop and bend over =(

I to had this issue. This is exactly what happened to my 06 when I had it. It was the head gasket.

stimula8's procedure for burping the system is a good thing to remember when you are refilling the system with coolant. However I feel you have some work ahead of you replacing head gaskets first.

To prevent this from happening again, please have the heads re-surfaced before installing the new gaskets. The MLS gaskets require a very smooth finish on both surfaces (block and head) to make and maintain a proper seal. I have had good luck with Tomei, SixStar and OEM gaskets. I had bad luck with Cometic.

I hope for your sake that it's not a head gasket. I had this issue for a little while and luckily it turned out to be air in the system. It took multiple sessions of burping before things improved.

[MENTION=5667]Bcz_sti450r[/MENTION], when was the last time you changed the oil? Oil could get contaminated with coolant if the head gasket was bad...or...coolant could get contaminated. You could have a bad head gasket without noticing either of the above conditions, but it's worth taking a look at I guess.

I completely burped out the system last night with a special funnel and its seems like its fine

Batmobile makes a good point, also a head gasket leak from the coolant passages in between the cylinders to the combustion chambers as well, where oil wouldn't be contaminated and coolant wouldn't be contaminated with oil, but with exhaust gases and you can get your coolant diagnosed with dye that makes it fluorescent to make the exhaust gases appear in your coolant. The coolant level being low is due to getting burned off during the stroke of combustion, and out the exhaust valves. Do you notice a sweet burning smell from your exhaust? All it leaves you with is coolant with exhaust gases changing the coolant to contaminated coolant but appears normal to the human eye.



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[MENTION=662]Batmobile_Engage[/MENTION] i changed my oil like 1500 miles ago and its light brown

Bcz_sti450r said:

I completely burped out the system last night with a special funnel and its seems like its fine

Click to expand...

Did you squeeze the top radiator hose?! Lol you'll get the final bubbles out!



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Bcz_sti450r said:

@Batmobile_Engage i changed my oil like 1500 miles ago and its light brown

Click to expand...

Hopefully not light brown like chocolate milk, like this photo. :lol:



THAT would be coolant in the oil.

Bcz_sti450r said:

I completely burped out the system last night with a special funnel and its seems like its fine

Click to expand...

Good. Well, hopefully it stays that way. Keep an eye on it and let us know in a week what you find.

Glad it was air, one of my buddys got their car back from the shop and his coolant lines were crossed and it was overheating n spewing coolant. Took awhile to figure it out.