Amazing overheating problem...desperate
This symptom caught my eye:
"-YES, pushes water out of overflow tank then bunches of hot hot steam"
This is quite abnormal, and indicates possibly that:
- The system is not getting anywhere near all the air out at filling (despite the hole in the t'stat). The coolant in the engine is flashing into steam in short order, and once the t-stat opens, just pressurized steam is coming out of the engine and pushes through the water in the overflow tank. The pressure would have to be somewhat high to do this, which indicates hard boiling in the block or heads. And I can't tell you how well or poorly the rad cap will seal in the presence of just steam rather than hot coolant.
Can I suggest that you go through the burping process slowly and repeatedly and with just 1-2 minutes of run time at any time, then allow a cooldown and repeat? Also, make sure the truck is pointed up hill; put it on a jack if you need to.
Another suggestion- Put a pressure gauge cap on the rad and stop every minute to see what is going on.
Questions:
- Does it do this if you start cold and idle, and not drive?
- What radiator? Does the cap actually match the rad opening for 100%
- What coolant is being used?
- Heater core hooked up? Do you open that when you burp the air out?
- Engine mounting normal? Not sloped 'downhill'?
- Any pix of the installation that you can share?
- Cooling fan(s) set up?
- Any excess water in the exhaust? Indicating that coolant is leaking out an exhaust port overnight?
- Yes it will do it if I start cold and idle, not drive...
- Good fitting, new 13 lb cap...
- Plain water and 1+ quart of antifreeze
- Heater open...installed large ball valve...wide open
- Stock mounted engine, I park the truck pointed slightly uphill\
- No "installation" totally stock truck/engine/exhaust EVERYTHING stock
- Cooling fan operates normally, belt OK
- No water in exhaust, no fluid loss overnight
- I recently installed that new 13 lb. (lift arm type) radiator cap
- I shortened and lowered the hose out of the top of the radiator, it is below the radiator fill opening now.
- I installed a 180 deg F. thermostat and drilled a small hole in it.
The problem seems to be cured folks. It has not done it for 6 or 7 trips now.
I really believe the 195 deg F. thermostat just wasn't opening because of air around it and the block got super hot and the pressure was going backwards through the water pump and out the overflow tank. When I bled off the pressure and added cold water, the thermostat was already opened...and the rest of the day was uneventful. It was just that start up and drive off in the morning (1 mile at 30 mph, then 2 miles at 55 mph)steam out from under the hood...blooey, stop, let off pressure, add water...everything normal again.
Dodge did say that the alternate choice in thermostats for my system was 180 deg.F
