So today i was at a stop light and I started to notice the jeep start to idle funny. Then all of a sudden there is steam coming from under the hood. I instantly looked at my temp gauge and it was one notch above 210. So i killed the motor, the light turned green and she started back up. I got it to a parking lot and looked under the hood and engine coolent was spewing out of the radiator cap. After it cooled down i inspected the cap and the seals looked normal. I drove it a few miles and it ran funny the whole time, felt like it was misfiring. I saw smoke so i stopped and smoke was coming from motor right by where the fuel injectors are. So i filled both the resvior and radiator back up with water and it still ran a notch above 210 all the way home. I have revved the engine to try and get the thermostat un stuck and i have inspected all hoses and clamps. Note no water was spewing out of cap the last two times I stopped only at first. Also I had a new radiator, water pump and thermostat put in two years ago so none of the cooling systems should be messing up. Im stumped, any ideas?
Just because something was new two years ago, doesn't mean it works now. Also, you need to Google 0331 head crack.
Overheating can be caused by anything that decreases the cooling system’s ability to absorb, transport, and dissipate heat, such as a low coolant level, loss of coolant (through internal or external leaks), poor heat conductivity inside the engine because of accumulated mineral deposits in the water jackets or radiator, a defective thermostat that doesn’t open, poor airflow through the radiator, a slipping fan clutch, an inoperative electric cooling fan, a collapsed lower radiator hose, an eroded or loose water pump impeller or even a defective radiator cap.
The cooling system is a group of related parts that depend on proper function from each of its component parts to keep the engine cool. Service the cooling system and replace any under-performing or suspected weak parts. Any component part of the cooling system that is not fully doing its job will stress the others and your cooling system will overheat. Temperature creep on the 4x4 trails, at idle, or in stop-n-go traffic points to a weak or failing mechanical fan clutch.
The most important maintenance item is to flush and refill the coolant periodically. Coolant should be replaced every 36,000 miles, or every two to three years. Anti-freeze has a number of additives that are designed to prevent corrosion in the cooling system, but they have a limited life span. The corrosion causes scale that eventually builds up and begins to clog the thin flat tubes in the radiator and heater core, causing the engine to eventually overheat.
-Use a flushing/cleaning solution and then drain and fill the radiator with a fresh 50/50 coolant and water mix. With a neglected cooling system you may have to flush several times.
-Inspect the radiator for mud/bugs/grass clogging the outside and mineral deposits clogging the inside. Clean or replace as needed.
-Replace the thermostat with a STANT or Robertshaw 195* thermostat. Cheap thermostats are cheap for a reason.
-Replace the radiator cap if your Jeep has one. An old worn out radiator cap will allow boil overs and/or allow the coolant flash over into to steam. You will see the coolant temps suddenly jump from 210* to the Red Zone and back to 210* if your radiator cap is weak.
-Inspect/test or replace the mechanical fan clutch. A worn fan clutch will allow temperature creep at stoplights, in heavy traffic, and on the 4x4 trails. A fan clutch that “looks” OK is not the same as working OK. Consider installing a Heavy Duty fan clutch such as the NAPA #272310.
-Inspect the electric cooling fan and the fan relay. Apply 12 volts and make sure the fan runs. Exchange the cooling fan relay with one of the others similar relays. Confirm that the e-fan starts when engine temps reach 215-218*. Repair or replace the fan or relay as needed.
-Inspect/test or replace the coolant temperature sensor that activates the e-fan.
-Replace the water pump. The pumping fins can deteriorate over time and the pump will not flow enough coolant to keep the temps under control.
-Inspect/replace the radiator hoses. Make sure the coiled wire is installed in the lower hose.
If you have covered all the points listed above and still have overheating issues, inspect and test the head for cracks and head gasket for leaks. Exhaust gasses entering the coolant can raise the temperature of the coolant or cause steam pockets in the coolant that will temporarily block the flow of coolant
Thank you so much. Did I mention its almost two years since I have had a/c ( I suspect the compressor because I have tried putting freon in it) and my heater hasnt worked for almost two years but i dont get any water inside the jeep. It has not been on a trail for about four years or any mud/sand, only the road. Not worried about the a/c or heat but maybe the heater core plays a role in this? Also I hear the fan kick on periodically not sure what temp. Im getting ready to go do a test drive with more specific info coming.
X2 on CJ7 Tims post. If it's been 2 years since your cooling system was serviced its probably time for at least a flush, And if your getting no heat and the HC is not leaking it is most likely clogged. As Tim mentioned do your self a favor and google 0331 head crack and keep a close eye out for unexplained coolant loss.