I have a 3 liter that over heats and boils aver aswell. The first time this happened i could not figure it out. i changed the thermostat and tested the fan. the fan always cut in. i even took it off and hooked it strait to 12volts. i drove it around for a couple of minutes and it got hot agian. well it was hot i turned the a/c on witch should automaticly turn the fan on and it didn't turn on. after more testing i found that for some reason that the fan would work most of the time but not always. it seemed when it missed a cycle for some reason it never caught back up until the engine cooled down from being turned off. i changed the fan and it worked great. for about a month. i changed the fan and it worked again for about another month. my suggestion is head for a post. worked good for me. hhah
HI;
Combuarion leaks do not always pass water into the crankcase. Combustion can pressurize and aerate theengine coolant and heat it at the same time.and burn or vaporize anything that enters the cylider. Of course the leakage would be and apparently minute in its early stages. You cando a combustion leak test yourself and here is how. Take the overflow out of the recovery bottle and submerge the end of the hose into a container of water. Something clear if possible. Have someone start the engine. Give the cooling system a chance to do its normalizing, about 5 minutes and watch the container. You are looking for bubble. tinybubbles coming from the hose. When yhey surface they might have a little smoke in them Small bubbles indicate the combustion pressures is being forced through a poor head gasket seal. Larger bubbles of course mean a replace now gasket situation. Now, Raise the engine RPMs to about 1000 to 1200. and watch what happens. Lots of bubbles mean the head is sort of bouncing and that verifies the smaller leaksare valid. Combustion leaks are the hardest to find. A cracked cylinder or cracked head will show up in your oil or out the wxhaust and you have chk'd that. The exhaust would be light steam. So, good luck and stay connected. If you find nothing let me know and we will work on it further. -Ned-
Try to remove the thermostat and see if works,i did that on many cars and they work fine ,good luck
It's not the head gasket....
Could be the bottom radiator hose to the water pump. It may be collapsing under the suction of the pump. Squeeze the lower big hose to see if it is squishy. There is a spring-like coil (like a stent) that supports the hose from being squashed like a toothpaste tube.
When your car heats up and thermostat opens (if installed), look at the bottom hose from the radiator and you will see it get mashed.
If you have a thermostat, the hose will squish, then open , then squish, etc.
I hope this solves the overheating issue.
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yes cycled the engine many of times with cap off and scanner on to make sure fan came on at 100 degrees then off! all air is out of system... drove car for a day with t-stat out.... next day again over boiled when shut car off after a drive... both with and without new t-stat in.
fan comes on at 100 C 207F as per Mitchel specs for this car! Yes hot air blows inside car.. Yes rad fan pulls heat from rad.. The rad is new and circulates fine! I never burp a cooling system with a/c on!
the fan should not come on until over 220f or so, with a/c on fan should run all the time. When the fan is on, and the engine is HOT, the air coming through the radiator should be HOT. if its cool, or lukewarm, you may have a radiator plugged up. how about the heater, does it blow blasting hot air when the engine is hot, or lukewarm.
Did you pressure test the cooling system? Results? If you had a head gasket, you would have several other indications, like lots of pressure in the cooling system, adn perhaps problems starting... Please describe the overheating...boiling over, spitting water out? Did you use coolant and water mix? Tell me more about the fans, do they cycle on and off? Did you bleed air from the system? Did you have the heater on high during filling? When pressure testing, you can tell if there is much air in the system, because it would take lots of pumps to get pressure... Doc
Did you bleed the system of air?
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