I have an '06 charger daytona, w/ 5.7 hemi. I have owned the car for 15 mos, and had a snowball rolling downhill with the cooling system. first the resoivor failed, which led to the radiator, then the water pump, and the radiator cap, and thermostat, and hoses. Everything had been replaced, except the lower hose,heater hoses, and heater core.
On a 1000 mile road trip, the lower hose sprung a leak. I replaced it, and refilled the cooling system, (50/50), ad considered it good. It ran in the 230 degree area, and cooled down to the mid 20’s, after i turned the a/c off.
I checked the thermostat, and found the port to be covered with an RTV looking goop. I changed the thermostat, and had my radiator professionally flushed. i checked the coolant as my mech told me, and it was about a quart or so low, so i refilled it. a cpl.days later, i found the bottle low again, and a considerable amount of coolant was on the ground. never found any coolant on the ground, but kept losing fluid. a friend told me it may be a small bust in the head gasket, so i added a bottle of cooling system/head gasket repair. No more low bottle, no fluid on the ground. BUT, i feel it runs hot, because it was running high 20’s, low 30’s. I then added VP fuels, coolant chiller, and took to the highway. it was running 226, at a steady pace; BUT, as i exited the highway, I punched the hell out of her and went from50 - 85 in a nano second, but the temp went to 231 just as fast. I parked for about 15 mins, and got back home , at normal speed (70) and ran at 226, all the way home. I caught about 3 red lights on the way. Forum I have read say norm is 219, dodge guy said as long as the temp ga. doesn’t exceed 3/4 range, I’m good. BOING !!! whats going on ? I haven’t changed the sending unit, but I’m as confused as a hungry baby, in a topless bar. HEP me pleeze !!! Thank you very much, Pete
I’d say the radiator is plugged with RTV and now stop-leak. Very likely you have a bad head gasket because running hot a number of times is never good for the head gasket.
There has been so much thrown at a 13 year old car with unknown, and a bit sketchy service history (where DID all that RTV come from???) to fix the problem without diagnosing the actual problem, there might not be a solution.
I’d start with a test kit to determine if this cooling system will even hold pressure. A shop can do this, or you can rent a tool. If it won’t hold pressure, it won’t cool. If it holds, the head gaskets are probably OK, for now. But I’ll bet it won’t hold.
Next is to see if the fan is working. Not sure if this has an engine driven or electric fan or fans. Drive it, get it hot, turn on the AC and see if the electric fans are running. If it is engine driven, make sure there is significant resistance to turning when hot, engine off, to check the fan clutch. Then drain the system, replace the radiator, new rad cap and the thermostat. I might even replace the water pump. Put it back together with only water and see how it cools.