Re: [Chrysler300] 300G Cooling System Over Heating..
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Re: [Chrysler300] 300G Cooling System Over Heating..

Many years ago, in a past life, I had a 67 Charger with a 383 4bbl with AC. I needed to replace my water pump, so I thought since it's a high performance car I should have a high performance water pump. I went to my local Napa store and bought a high flow pump. Worked nice until I took it out on the highway. It began to overheat, so I got off the highway and drove back home on a rural road, The temperature went back to normal.
To make a long story short, I took off the high flow pump and replaced it with a regular OEM pump. The car worked flawlessly after that. The issue was, at highway speed, the high flow pump was flowing the coolant through the radiator too fast, and it didn't have enough time to cool when going through the radiator. During rural road and city street driving there was enough time for the coolant to cool down going through the radiator. And we all lived happily ever after.
-----Original Message-----
From: 'John Grady' jkg@xxxxxxxxxxxxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx>
To: ttibbie <ttibbie@xxxxxxxxxxx>; Chrysler300 <Chrysler300@xxxxxxxxxxxxxxx>
Sent: Thu, Apr 6, 2017 10:44 am
Subject: RE: [Chrysler300] 300G Cooling System Over Heating..

There is a slight chance you have a wrong water pump or pump housing..there are some problems with certain 440 pumps currently routinely sold for 413 replacements , where some kind of metal plate or spacer is inside the pump housing and sometimes not. I do not know all the details, but bottom line is any given housing and pump must be made for each other. Add to this the variation in AC pumps (impellor design ) or not.
As I understand it, from memory,  a situation can happen where there is a gap behind the impellor to the casting, due to incorrect mix and match, so flow drops . Even if it fits bolts, it might be the wrong one. . Sorry for lack of specifics, it was long ago.
Perhaps see if you have strong flow in the radiator at slightly off idle say 1500 rpm???  also if water is moving well, then  generally radiator is almost  same temp top to bottom ; if slow top gets a lot hotter. (IR temp gun) Also attempts to make the radiator look nice with shiny black paint are obviously 100% in the wrong direction. Painted fins cannot throw heat well.
Although I have no personal experience, there is a co selling both pump parts claiming hi flows , “flow cool” or something, hi flow water pump ;  If it gets to that.. If marginal pump , would expect hot in traffic, OK on highway at higher RPM?
Not sure, of course,  if this is valid for you, but had some problems like this in past years with 480” 440 in 57 Dodge, built from various parts.  ; overheats at idle, all new stuff!!
From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of ttibbie@xxxxxxxxxxx [Chrysler300]
Sent: Thursday, April 06, 2017 9:29 AM
To: Chrysler300@xxxxxxxxxxxxxxx
Subject: [Chrysler300] 300G Cooling System Over Heating..

I live in south central Texas (San Antonio) I purchased my current 300G last April 2016. The cooling system with AC is new including radiators, hoses, fan etc are all in new condition.. I've installed a recovery tank but the I'm still having problems with over heating on days where the temperatures reach 90 plus. Any suggestions.        


Posted by: Mark Souders <mrs954@xxxxxxx>

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