Question about 1999 Cadillac DeVille
I have an overheating problem when driving at highway speeds (55mph+). I can let car idle for long periods of time and no problem, drive 40mph or less, no problem. I recently replaced a cracked radiator, put on new hoses, replaced thermostat and surge tank cap (16#). Upper radiator hose heats up fine, thermostat opens around 195', plenty of heat, no white smoke from exhaust, no visible leaks or puddles, purge line flows. I revved engine up to 2500 rpm for several minutes to warm engine up with temp set at max hot. Symptoms: I put a cup under surge tank overflow line and captured coolant escaping from NEW Surge tank cap. If system is building pressure when hot, blows out coolant through surge tank cap/overflow line, then overheats-probably from low coolant, is this an indication of a blockage, trapped air, a blown head gasket or something else?
Posted by Anonymous on
Could be a air pockets in the coolant system that have top bled out
it is a simple exercise to have a compression test done to check for head gasket or cracked head
Posted on Mar 14, 2017
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Posted on Jan 02, 2017
IF COOLANT SYSTEM BEEN BLED AND PLENTY COOLANT IN COOLANT SYSTEM. THE IGNITION TIMING LATE OR VALVE TIMING LATE TIMING CHAIN WORN WITH A LOT OF SLACK JUMPED A TOOTH ON CRANKSHAFT GEAR TEETH OR ENGINE CYLINDER BLOCK WATER JACKETS CLOGGED ENGINE BLOCK NEED FLUSHING. IF ENGINE OVERHEAT WHILE SITTING IDLING LONG TRAFFIC LINE COOLANT FANS NOT TURNING ON.COULD HAVE FAULTY ENGINE COOLANT TEMPERATURE SENSOR OR FAULTY COOLANT FANS RELAYS OR BLOWN FUSE.PCM FAULT.CHECK ENGINE OIL IF IT LOOKS LIKE MILK SHAKE YOU HAVE BLOWN HEAD GASKET.
Posted on Jun 05, 2011
Buy a block tester. It hooks up to your radiator and lets u know if exhaust gasses are mixing with your coolant wich would mean u have a (blown head). Do this before you spend anymore money.
Posted on Dec 10, 2012
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