Heater core flow
01-30-2016, 07:02 PM
#1
Heater core flow
My silverado lost heat the other day, just so happened to be the coldest day we have had so far this year. The hose on the left side of the heater core was lukewarm and the right side hose was cold, as was the bypass hose at the right side radiator tank, and the system was building pressure in the reservoir along with the coolant looking really dark (almost black) through the reservoir. Thinking the internal trans cooler in the radiator started leaking into the coolant. I am going to replace the radiator tomorrow, i want to flush the heater core(which i just replaced when i put the engine in) which way does the coolant flow through the heater core, in through the left hose and out through the right, or vice versa??
01-30-2016, 07:30 PM
#2
If the trans cooler was leaking, you'd have a strawberry coolant color. It looks just as good as it tastes.
Dexcool is known to brown up over time and the res tank is the rad cap you know, it's suppose to build pressure. Not sure if that was a concern of yours, but thats normal.
I'd back flush the heater core both ways. And you already answered your question on what way it flows, you already grabbed the hoses. The hotter hose is the hose where the flow starts.
Dexcool is known to brown up over time and the res tank is the rad cap you know, it's suppose to build pressure. Not sure if that was a concern of yours, but thats normal.
I'd back flush the heater core both ways. And you already answered your question on what way it flows, you already grabbed the hoses. The hotter hose is the hose where the flow starts.
01-30-2016, 08:40 PM
#3
It had enough pressure it kind of erupted when i pulled the cap, not normal pressure, ive seen dexcool turn brown this was not like that it has an oily looking film on top of the coolant.... Would think, with the bypass hose on radiator being cold and no heat and the radiator wasnt hot on right tank but was on left, and cold air coming off the fans, i have a clogged radiator... Thing that irritates the hell out of me is i just replaced the radiator, heater core, etc when i swapped the engine, hell everything under the hood is new...... I have maybe 1500-2000 miles on it since the swap/build!!!
01-30-2016, 09:22 PM
#4
Coolant system operate under 13-16 psi, it really doesnt take much to cause the coolant to start shooting out once you remove the cap. If the vehicle was already warm, it's still under pressure.
I've been a mechanic for a while now, that film is still pretty normal with dexcool. Dexcool and air do not like each other, the more air it see's the more likely it is to produce the film and change colors. And if your new motor had any oils inside the block/coolant chambers and that mixes with dexcool, it's just going to make it like that.
I've been a mechanic for a while now, that film is still pretty normal with dexcool. Dexcool and air do not like each other, the more air it see's the more likely it is to produce the film and change colors. And if your new motor had any oils inside the block/coolant chambers and that mixes with dexcool, it's just going to make it like that.
01-30-2016, 09:44 PM
#5
Formerly ScreamingL
Dexcool was GMs answer to fixing small leaks...once it mates with air it starts to fix things...problem is heatercores are a side issue..once dexcool mixes with air 9-10 times a heatercore will clog solid
The fix to this is remove dash replace heatercore
Then figure out leaks
The fix to this is remove dash replace heatercore
Then figure out leaks
01-30-2016, 09:55 PM
#6
Come to think of it, it was fine until shortly after i installed the 40k, im going to start with the radiator and flushing the heater core and go from there, have lifetime warranty on the water pump, radiator and heater core.... Just really hoping not to have to pull my dash again.....
02-01-2016, 06:59 PM
#7
TECH Fanatic
Come to think of it, it was fine until shortly after i installed the 40k, im going to start with the radiator and flushing the heater core and go from there, have lifetime warranty on the water pump, radiator and heater core.... Just really hoping not to have to pull my dash again.....
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02-01-2016, 08:41 PM
#8
Hopefully ill be able to get to it tomorrow...Havent had time to mess with the truck yet, been working too much, what are odds my waterpump isnt circulating properly or enough, i had replaced it about 2 years before the swap so i really saw no point in replacing it again at that time....when i did the swap i replaced the heater core, complete ac system, belts, hoses, radiator, added 06 efans, etc etc etc, and having a lifetime warranty on water pump shouldve gone ahead and replaced it but.... I didnt.... If it ends up being the problem, i will end up getting it warrantied out and will giveme an excuse to expedite my new cam, figure since i have to pull pump anyway, may as well go ahead and swap cam out at same time....
