I'm having problems with my car running hot, or at least that's what the temperature gauge displays. This only happens when the car is first warming up after startup. The temperature gauge will continue to climb slowly towards overheat temperature but if I turn the heat on the air blows cold like the car has not warmed up yet. If I keep the heat on full blast the air blowing out eventually gets warm and the temperature gauge will drop dramatically, all the way down to 185 to 195 degrees. Once it drops to normal range I do not have any more problems for the duration of that driving session. If I stop for anything and restart I will have the same problem all over again. I have the predator and motorad tstat and haven't had any problems for 6 months, now it happens every time.
My C is running on average 225 sometimes more and the oil temp got up to 245 saturday night. But I do drive mine like hell. once i hit the interstate she cools off from all the air moving I guess. In slow traffic she gets hot again.
Do our cars have to be vacuum flushed when doing a coolant flush?
Good question. According the the Haynes manual "reverse" flushing is only done in the presence of severe contamination.
The routine flushing process (once everything is empty, including the block) involves removing the thermostat, reconnecting the hose and running a "garden hose" into the upper radiator port until the clear water exits the upper radiator hose. Then refill with proper mix until a bubble-free mix streams from the bleeder plug (you can replace this plug with a bleeder valve for future flushing (its a 1/4 -18 npt thread on the V8). This valve can be gained at the dealer or auto parts store.
2012 !!! 300 SRT8 Bright Silver (PS2)
Stock Dyno = 423 RWHP and 417 RWTQ (92 degree day!)
Mods have begun
Diablo T-1000 / 93 Octane Tune
Modern Muscle 87mm TB
New Dyno run pending...stay "tuned"
Sounds like air. When you firt start the car turn off all the extras and listen for a gurgling sound coming from the dash. Like water rushing. Thats air in the system. It needs Burped. Run the car after its been cold with the Coolant resivoir cap off. That should let the air out. Be carfull and please don't burn your self.
If that doesnt work could be the termastat is bad. The stock one can go bad. I can't remember if they have a release hole in them or not.
Car running hot??? YOU GOT AIR IN YOUR COOLING SYSTEM--
if your lower radiator hose is cold and your upper hose is hot- and your car is running hot---Locate air bleeder valve ( top of intake manifold up front) and bleed the air out of your cooling system when car is at running temp. - keep going and going got to get ALL the air out do this repeated opening and closing of this valve..air and coolant will hiss out keep going - like a volcano at first then it will gradually calm down- do it w/ car running and turned off- - this could take about a half hr of repeated actions- throw a towel over you motor if your finicky about cleanliness..
you'll need to add fresh coolant as you bleed the thing--- air in system will ABSOLUTELY make it run hot--- when you're done- see gauge it will be perfect- the bleeder valve will only be flowing ONLY Coolant out of this valve and your lower hose will be hot like it's supposed to be.
You have air in your engine / coolant system.
The air valve on top of your manifold is not going to remove all the air inside. Which is causing your thermostat to not open sometimes as that air pocket moves around your system.
You need to take it to a mechanic that has a Snap-On or other brand of mechanical vacuum pump with the gauges built in to the tubes etc..
they need to suck ALL THE AIR OUT of your motor- it may take two attempts or more-
like mine did!-- guess what?---problem solved!---only took 2 months of wondering & stress, 1 new radiator, 1 new themostat, 4 new water pump housing o-rings, 1 new water pump, hundreds of bucks and many hrs of time....but my mechanic figured it out-- that Snap-on air pump cost him $350 off the the Snap-On truck...but now every stinkin' molecule of air has been sucked out my motor--and my gauge reads 1 mark BELOW the half point- It feels and runs like a champ- no more stress on me either....and I have an entirely new cooling system..(that I did NOT NEED!) but what the heck it's ok...
So the moral of this story is - if I had known the running hot problem could have been solved by just using that mechanical pump to begin with ( and NOT relying on that little relief valve- I could have saved myself tons of grief and money.
Wow, such an old post but so very helpful. Can somebody give me a diagram of where the bleeder valve is? I want to try that first and then try the overflow take cap off when I start it tricks. Don't want to over pay a mechanic to vacuum this out if I don't have to.
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