03 Gt


New Member
Jan 5, 2014
Car makes a boiling/bubbling sound when I start it, or come to a stop. Engine idle also fluxuates randomly when at a stop. What could this be and how can I stop it??
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More info, mods or tunes? If you do have a vacuum leak, local mechanic should be able to run smoke through vacuum system. On the upside engines produce water from the air so when it is cold on start there is some H20 in the system.
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When I owned my 2003 GT, it made this same bubbling noise. Heard it in the area of the heater core, so I just assumed it was air bubbles in the cooling system bleeding through the core.

Never addressed it. Car ran great from time it was new to 100k miles when I traded it in.