Getting real nervous about heat

Desert Sasqwatch

Goblin Guru
Supply line to the pump should be connected to the bottom port of the radiator. Gravity will always work with in supplying water to your pump in this configuration.
Connected in this manner your radiator could only be half full and still circulate coolant. It won't the other way around as the pump can't pump air.
Always better to have the coolant pulled from the bottom of the radiator where there will be fluid, rather than from the top where it could betrying to circulate steam.
 

Zoom Zoom

Goblin Guru
Here's where it is on the SC head. Found a picture lol, that lets u leave that coolant hose hooked up, and it'll fill everything from the radiator back and let all the air out on that side if u have it in the same spot on the tc
Hook up a blow gun to this hose with 10 psi. and blow coolant threw system until coolant comes out of hose connection then that means you have coolant in entire engine, keep a close eye on coolant tank because it will sink down quick if you need coolant in engine, you don’t want air to get in coolant tank,
THIS IS HOW LONNY EXPLAINED TO ME HOW TO DO IT.
 

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SwerveMonkey

Well-Known Member
Always better to have the coolant pulled from the bottom of the radiator where there will be fluid, rather than from the top where it could betrying to circulate steam.
I need to ask to make sure I understand... is the flow going out of the engine on the passenger(right) side, and cooled liquid coming into the engine on the driver(left) side?

EDIT: I FOUND IT!!!
The hose on the right (passenger) side comes from the top of the head, HOT water. The left side returns cooled water from the radiator to the thermostat to the water pump and then into the engine block.


.... If your tune is still factory the fan won’t turn on till 217°F
I did not realize that the fan only came on at such high temps... I suppose I had an over-abundance of caution ripping things apart.
 
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Christopher Sanchez

Well-Known Member
Hey guys I have tried everything I can think of to bleed the radiator and lines. I have used about a gallon and a half of fluid. Reservoir is half full I have massaged the line going through the frame and run the car to try and get the new thermostat to open but so far I haven't had much luck. I feel the heat coming off the engine and I can feel the radiator is really hot but the line from the thermostat housing to the radiator and the passenger side hose feels cool to the touch. What am I missing here?
Unclear if you have resolved this issue yet or if i am missing part of your concern here however when I first allowed my build to fully get up to temp I was surprised about how long it actually took to warm on both sides of the radiator hoses. 10-15 minutes to finally cycle the rad fan if i remember correctly I was concerned about air pockets also, finally I borrowed a cheap obdll monitor from a friend to monitor coolant temps. I think he said they were like 19.99 on amazon. My rad fan kicks in around 202-205 and brings it down to 195ish then shuts off. Others on the thread seemed to think this number was to high however I owned a 2009 cobalt for 5+ years and the fans did the same. Going on two years with zero issues. I will say that i rarely hear the rad fan kick on unless i am really beating on the thing! ;) temps stay 170s-180s cruising
 

Mayor West

Goblin Guru
I ordered one of those vacuum fillers (not the one linked because it had horrible reviews) and it arrived today, just ran it through and I can't really tell if it pulled all the air pockets out but it does appear to have done a decent job at creating a vacuum in the system.
 

Kenny123

Well-Known Member
I ordered one of those vacuum fillers (not the one linked because it had horrible reviews) and it arrived today, just ran it through and I can't really tell if it pulled all the air pockets out but it does appear to have done a decent job at creating a vacuum in the system.
Honestly man a couple times around the city and the reservoir dropped and she is running great.
 

marksdad

Member
Working with my son on his goblin. Used Bluetooth OBD2 to watch the engine temp. Got to about 210 and the fan never kicked on. We shut it down. Tested the fan directly off the battery and it worked fine. OBD readout showed the temp gradually rising so I think the sensor is good. Any ideas how to troubleshoot?
 

PyroGuy923

Well-Known Member
Working with my son on his goblin. Used Bluetooth OBD2 to watch the engine temp. Got to about 210 and the fan never kicked on. We shut it down. Tested the fan directly off the battery and it worked fine. OBD readout showed the temp gradually rising so I think the sensor is good. Any ideas how to troubleshoot?
I'm in the same boat. Bought a brand new thermostat from Rock Auto that is 180 degrees. Someone just posted that the fan won't kick on until 217 so going to test it tomorrow.
 

Christopher Sanchez

Well-Known Member
Working with my son on his goblin. Used Bluetooth OBD2 to watch the engine temp. Got to about 210 and the fan never kicked on. We shut it down. Tested the fan directly off the battery and it worked fine. OBD readout showed the temp gradually rising so I think the sensor is good. Any ideas how to troubleshoot?
After a Quick cobalt forum search seems as though different models kick in at different temps.. 2.2 seems to kick in 215-220 maybe some others on the forum with completed builds can chime in with their temps (include engine model) in which the fan kicks in. My turbo models kicks in around 202-205.. even at 220 you’re not hurting anything I’d just monitor both rad hoses to ensure coolant flow they should both warmif your temps get much past 220 using obdll without the fans kicking in then shut it down..I know it’s nerve racking but once the fan kicks in and you realize it’s a functional unit the feeling is similar to the feeling of the first start.. good luck!
 

Kenny123

Well-Known Member
So after driving a lot I have learned that the fan comes of only after really getting on it. I dont have info on temps however it does kick on when needed.
 

Ross

Goblin Guru
Working with my son on his goblin. Used Bluetooth OBD2 to watch the engine temp. Got to about 210 and the fan never kicked on. We shut it down. Tested the fan directly off the battery and it worked fine. OBD readout showed the temp gradually rising so I think the sensor is good. Any ideas how to troubleshoot?
You can jump the radiator fan relay and see if that will turn on the fan. (Like the way we jumped the fuel pump relay when we emptied the gas tank) That would have helped find PyroGuy923's issue.
If the fan relay is working, then the only thing left is to get a signal from the ECM computer, which can be switched on in HP Tuners to test your ECM.
 

marksdad

Member
I'm in the same boat. Bought a brand new thermostat from Rock Auto that is 180 degrees. Someone just posted that the fan won't kick on until 217 so going to test it tomorrow.
Turns out we had not connected the blue wire near the fuse box to the old radiator connector blue wire. Did that and the fan kicked in around 205. All seems to be working well now.
 
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