help me understand cooling systems
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help me understand cooling systems i had my motor rebuilt by a sponsor here and i brought it home on friday. i've driven it three times since including the drive home from teh shop. it seems that if the car is ever at full temp for 20 minutes, teh car goes higher than normal operating temp (about half way to red past normal operating temp). i figured it was a bubble so i let the car idle with the cap loosened for a couple minutes and then tightened it back up. still got hot. the following morning, i opened the radiator cap and saw the coolant was all the way to the top. so i concluded that it wasn't a bubble because had there been a bubble in the system, it would have traveled to the highest point, which is by the radiator cap.
now the fans turn on, the thermostat wasn't replaced, and the waterpump seems to be working fine as everything was before the new motor. what other possibilities am i missing? there is no debris blocking the radiator and the air dam is in place. is there another part to the cooling system that i am overlooking?
now the fans turn on, the thermostat wasn't replaced, and the waterpump seems to be working fine as everything was before the new motor. what other possibilities am i missing? there is no debris blocking the radiator and the air dam is in place. is there another part to the cooling system that i am overlooking?
Last edited by qwikz28; Jul 13, 2008 at 01:01 PM.
Do you have AC on? Yesterday was 98 here and i had AC on in my 94 Z and it was running at almost 230 after driving about 2 hours.
Are you running coolant or just water?
Did they replace your headgaskets as well? I say replace thermostate just because you didnt and look for leaks as mentioned.
Are you running coolant or just water?
Did they replace your headgaskets as well? I say replace thermostate just because you didnt and look for leaks as mentioned.
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Do you have AC on? Yesterday was 98 here and i had AC on in my 94 Z and it was running at almost 230 after driving about 2 hours.
Are you running coolant or just water?
Did they replace your headgaskets as well? I say replace thermostate just because you didnt and look for leaks as mentioned.
Are you running coolant or just water?
Did they replace your headgaskets as well? I say replace thermostate just because you didnt and look for leaks as mentioned.
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next question is: How long does it take coolant to get all the way through the system?
i bled the system out three times, and air keeps accumulating (i end up adding about a cup of coolant each time, where does the coolant go?). changed the radiator cap because i saw no leaks so i guessed air would be leaking through there. didn't swap the thermostat or water pump yet because i don't understand why i'm getting air.
i bled the system out three times, and air keeps accumulating (i end up adding about a cup of coolant each time, where does the coolant go?). changed the radiator cap because i saw no leaks so i guessed air would be leaking through there. didn't swap the thermostat or water pump yet because i don't understand why i'm getting air.
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Once the system build pressure it flows quickly. Leave the cap on and warm the car up and then squeeze the radiator hose, you should be able to feel the flow of coolant in the hose. If you feel it then it is flowing and there might just be something obstructing 100% flow. The first culprit being the thermostat.
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another member linked me to some information that is leading me to believe that the head gasket is the culprit. there is definitely flow, that is without question. but somehow, air is leaking into the system. when i run the car with the cap off, the bubbles rush to the top and pop, and i then add more coolant. i have been doing this for 3 straight days, everyday adding more coolant. the motor is just rebuilt which is why i'm baffled as to why the head gasket could be the problem, but hey thats always a possibility. of course i'll be taking it back to the shop so they can troubleshoot it. just tryin to skip the trip. thanks for the heads up guys 
Run a leakdown test on it and see if it looses pressure. Do you smell coolant or see steam in the exhaust? I have even seen them pump coolant out the tailpipe after the leakdown test in extreme cases. You can also go to NAPA and buy a test kit and check for exhaust gas present in your coolant. Good luck!! I am running a little hot too but don't think I have a HG problem.
to purge the air out of the system, take the cap off, warm up... then raise the RPM to 2000 for about 20-30 sec.. let off and idle.. check coolant level.. then repeat the cycle two more times and replace the cap.
Maybe that will burp the system better.
What CAM did you put in, did the build rasie Compression.. these two items can and will cause higher operating temps..
Maybe that will burp the system better.
What CAM did you put in, did the build rasie Compression.. these two items can and will cause higher operating temps..
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to purge the air out of the system, take the cap off, warm up... then raise the RPM to 2000 for about 20-30 sec.. let off and idle.. check coolant level.. then repeat the cycle two more times and replace the cap.
Maybe that will burp the system better.
What CAM did you put in, did the build rasie Compression.. these two items can and will cause higher operating temps..
Maybe that will burp the system better.
What CAM did you put in, did the build rasie Compression.. these two items can and will cause higher operating temps..
i'll try your burping system tomorrow morning.
If its burping air all the time the head gasket is a likely cause. A jacked up head gasket is also even more likely since you just had a rebuild. Could be the wrong gasket or just bad sealing on the gasket.
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i'll have TTP do a once over on it. hopefully i'm just not bleeding the system right but i doubt thats teh case. i'm just concerned about that i'll end up paying for a new pump and thermostat and stuff only to find out it was a bad gasket or something. hopefully i'll see tomorrow when i try burping it again, if not its going to TTP on monday. thanks guys
You cant bleed the cooling system wrong. You fill it up, cap it, run it, then uncap it and fill. When I put my motor in I filled it, drove it, and topped it off once more, that was it. No special crazy bleeding is required.
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in any event i tried multiple methods and it still got hot on me on the way home. there was no air in it this time too. i give up on trying to fix this thing, i hope TTP has more patience than i do
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they did. they replaced the waterpump free of charge with a LS2 one (supposedly flows better) but the car is still getting hot. i contacted them and they wanna replace the thermostat cause they believe (and i agree) that there is probably something wrong with the current one. they offered to do it for me but they are busy and i don't feel like driving down and also since the weather isn't too hot the car is running fine. i will probably replace it on my own sometime. its the only part of the cooling system left to be checked besides the sensors so its probably it. all this grief for a freakin thermostat
ps- TTP is awesome. this really isn't their problem but they took it upon themselves to fix it. thats really fantastic IMO.
ps- TTP is awesome. this really isn't their problem but they took it upon themselves to fix it. thats really fantastic IMO.
FYI the gauges in these cars are a complete joke. had a friend with a turbo lsx car.....HP tuners said his coolant temp reached 238.....the stock gauge said it was perfectly fine in the halfway area.