Milky substains in coolant

Blown head gasket allowing coolant to enter engine. Check engine oil dip stick for presence of coolant (milky).

look for water out tail pipe after you warm it up then rev motor to 1500-
2000, ,check oil for milky color on dip stick, and trany fluid &cooler for milky color, check coolant tank for,
smell of exhaust or just not a clean coolant smell , if in dought open a bottle of anti freez thats what it should be like, im thinking head gasket
or a small leak under pressure when driving ,gurgling is coolant moving back to coolant tank an back to motor. good luck ,
hope some of this helped , H.WOODY.

if it's coolant their wouldn't be a milky mixture, the trans cooler is whats located in the radiator it's possible that when you replaced the overflow tank the seal was compromised check these hoses to be sure they are tight do you have pressure in the system check this by squeezing the upper rad hose if you have pressure check around hoses for leaks. you may need to have you unit pressure checked at a garage

I WOULD CHECK BOTH RADIATOR HOSES TO MAKE SURE THEY ARE HOT. THERMOSTAT COULD BE STICKING SLIGHTLY CLOSED.CHECK COOLANT LEVEL MAKE SURE COOLANT NOT LOW.IF COOLING NOT BOILING OUT OF THE EXPANSION TANK. I WOULD HAVE CAR HOOKED UP TO A DIAGNOTIC SCANNER AND CHECK COOLANT TEMPERATURE SEE IF TEMP. OVER 230 DEGREES IF SO RADIATOR COOLING FANS NOT WORKING.COOLANT THERMO SWITCH BAD BOTH FANS SHOULD BE RUNNING AT LOW SPEED.IF ALL LOOKS GOOD YOU COULD HAVE FAULTY LOW COOLANT SENSOR IN EXPANSION TANK.MAKE SURE COOLANT IS IN THE EXPANSION TANK BECAUSE COOLANT LEVEL COULD BE LOW.ADD COOLANT IN THE EXPANSION TANK UNTIL YOU AT MAX LEVEL LINE ON THE EXPANSION TANK.DONT OVER FILL THE EXPANSION KEEP ADDING COOLANT UNTIL COOLANT LEVEL STAYS AT THE MAX LEVEL LINE ON THE EXPANSION TANK.

Is it overheating or just a gauge malfunction? Are you low on coolant? Check at coolant tank. If it is overheating, check for coolant leak at hoses. If no luck there, you might have a head gasket blown. Do you see white smoke coming from tailpipe? Do you see milky substance on dipstick or in coolant tank? These are signs that your head gasket has failed.

Ok reservoir has a full line do not fill above that. If you do it will vent and siphon water out of the tank and become low.

Head gasket failure is probable cause. Did engine get hot? Can you see milky substance on the dipstick? Is there a milky substance in the radio fill tank? All indicators of oil mixed with coolant

Yes, fill your reservoir and see if you have a leak there....if it is something worse, drain some oil from the oil pan and see if you have coolant or a milky look to the oil. Another thing to is your water pump may have bit the big one.

If your oil is milky it is a blown head gasket or worse a warped head.

milky oil means blew a head gasket check for oil in the antifreze