Engine Cooling problem
1987 Toyota Supra 6 cyl Two Wheel Drive Automatic 62000 miles
I have a bubbling noise from the dash, sometimes when revving it slowly I hear a little " gurgle", but most of the times its a hitch pitched rushing noise from the dash, gets louder with acceleration.
I was told it could be air bubbles trapped in the cooling system, and the way to fix this is to get a funnel, place it on the filler hole on the radiatior and fill it up with water, block the overflow nipple on the overflow bottle, run the engine with the heater on, and that the water in the funnel would displace the air bubbles. People said you would see air bubbles coming out, but I ran the engine for a long time and no air bubbles came out.
Also I was told that another way to get rid of the air bubbles is to park the car on an incline and to jack it up very high and let it run without the radiator cap on, I did this but no air bubbles came out.
So is there any other ways to remove these air bubbles, Somebody said that I could have a blown head gasket or a vacuum leak in the heater core.
I don't understand about the vacuum leak in the heater core, is there some sort of vacuum line from the engine to the heater core? What does it do?
Could it be a blown head gasket pressurizing the heater core causing the bubbling, but in that case wouldn't I be losing coolant? I havent noticed that I've lost any coolant.
Any other Ideas?
I'm open to any Ideas or Suggestions and am willing to give things a go.