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ThR1LLr 02-12-2012 02:36 PM

Heat cold when idle?
The heat is abnormally cold while idle, but will pickup after accelleration. Heater core replaced last 2,000 miles.147k on the clock.

New Waterpump
New Thermostat
...less than 100 miles and is still the problem.



Frango100 02-12-2012 05:21 PM

Re: Heat cold when idle?
Check the heater hoses in the engine bay for any kinks or sharp bends, this would restrict the liquid flow.

01grand 02-12-2012 05:26 PM

I would double check the thermostat if the hoses are ok. The new t stat is the same temp (195 I believe) as the old one right? Could also be a blockage in the heater core.

ThR1LLr 02-13-2012 12:24 AM

Re: Heat cold when idle?
Problems were before water pump and tstat removal.

I flushed the core once, it was so hot for a while then after that it was no longer... But i am also loosing coolant still.

I dont see signs of headgasket leakage either.

Plugged radiator maybe? I will double check but last time i tried to drain the radiator nothing would come out not a drop...

Frango100 02-13-2012 05:26 AM

Re: Heat cold when idle?
With plugged radiator you probably mean a plugged heater core. A plugged radiator would cause the engine temperature to rise or even overheat it.
If after flushing it, it was heating strong and then stopped again, its probably a plugged heater core. You could try to reverse flush it, to get any particles out of it. You could also have a slight leak from the heater core. No wet carpet on the passenger side?

ThR1LLr 02-13-2012 02:43 PM

Re: Heat cold when idle?
Wet carpet. Soaked. But can't tell if it's soaked from when heater core gave out last time at 1443k

Frango100 02-13-2012 04:58 PM

Re: Heat cold when idle?
If youre still loosing coolant, you have a good change that there still is a leak on the cabin side, maybe one of the hoses.
Did you check the heater hoses in the engine bay if they run free, without sharp bends or kinks?

2005JGC 02-13-2012 06:02 PM

Re: Heat cold when idle?
Its not uncommon to have an aftermarket heater core leak... sometimes mopar ones leak, if you have wet coolant coming down the firewall its sounding like the dash is going to need to come back out.

ThR1LLr 02-14-2012 02:51 PM

Re: Heat cold when idle?
Dropped it back at the shop I had the heater core done. They will be removing the dash and redoing their work.

ThR1LLr 02-28-2012 08:29 PM

Re: Heat cold when idle?
Got it back from PALMER DODGE In ROswell no leaks in coolant so far, pressure tests come back normal. It has been not leaking since repairs but heat still sucks i mean only when i accellerate.


ThR1LLr 02-28-2012 08:45 PM

Re: Heat cold when idle?
noticed my electrical fan will never cut on?

jeepgcoman 02-28-2012 09:01 PM

Re: Heat cold when idle?
In your first post you indicate that the low/no heat condition is while idling, and in Post No. 10 you indicate the low/no heat condition occurs when accelerating. Which is it? I am not sure, but I believe they are, if the control valves are vacuum operated (vacuum motors), they will go to the "unloaded" (probably off) position at low vacuum, such as when accelerating. They will go back to the correct (heat) position once the vacuum increases at cruise or deceleration. Try sticking a vacuum gauge on it and drive it to see if low vacuum conditions mirrors the low/no heat condition. Also, make sure there are no vacuum leaks (disconnected/broken hoses), especially under the dash in the area of the heater control valves. Let us know what you find.

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