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radiator/thermostat problem??

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crazyquik22023

10+ Year Contributor
641
6
Sep 14, 2008
Akron, Ohio
ok so my car has driven fine for about a month now, i was driving home yesterday and it overheated.. pulled over and the thermostat housing wasn't sucking up any coolant from the resevior it was just making the coolant bubble. so i waited a few minutes till it cooled a little and opened the thermostat housing cap and poured water in to cool it down.. Then drove home for 35 min and the temp was holding between 200-206 deg. the whole time... then took it for another drive a few hours later and it held the same temp the whole time... then it overheated on the next drive... opened the thermostat cap and poured water in and closed it then it held the temp fine again... this happened about 3-4 times where it kept overheating and then i let the pressure out by opening the thermostat housing and poured water in and then it held the temp of around 200 for a good 35-40 min drive. What could be causing this problem??? i have a newer radiator(1 yr old), new coolant temp sensor(1 yr old), brand new thermostat(4-5 weeks old) no coolant leaks or anything anywhere...
 
option1 could be a massive air bubble in the system try bleeding the system again option2 try a new thermostat alot of aftermarket thermostats fail in the closed position forcing water out through the overflow causing this problem. option3 intermittent fan relay make sure your fans are kicking on option4 check to make sure you didn't blow a head gasket you could be boosting into the water jackets forcing the water out your overflow either way its losing water some where!

if you go through all that there's still some other stuff to check LOL hope that helps
 
I just went through this problem a couple of weeks ago. You need to bleed the system. Take the thermostat housing cap off, fill with coolant/water, and then let car warm up to operating temperature while the cap is still off (20 minutes or so). You will notice when the thermostat opens because the water will flow quickly through the thermostat housing. Let it cycle a couple of times keeping it filled to the top. The air bubbles will find there way to the opening. Replace cap and you're ready to go. If you don't see the water cycling after 30 minutes, your thermostat isn't opening and needs replaced.
 
if you are missing water over the course of a couple of day it sounds like the water pump fill your car with coolant, then let it idle and see if it's dripping from the water pump oh keep an eye n the temp gauge too
 
I just went through this problem a couple of weeks ago. You need to bleed the system. Take the thermostat housing cap off, fill with coolant/water, and then let car warm up to operating temperature while the cap is still off (20 minutes or so). You will notice when the thermostat opens because the water will flow quickly through the thermostat housing. Let it cycle a couple of times keeping it filled to the top. The air bubbles will find there way to the opening. Replace cap and you're ready to go. If you don't see the water cycling after 30 minutes, your thermostat isn't opening and needs replaced.

ok i tried this once after my car overheated and it was slowly sucking the coolant into the thermostat but if i revved it a little bit to like 1400 coolant just overflowed through the thermostat hole. so i shut the car off and closed the cap and it held a temp of around 206 for the 35 min drive home?!!! so u think this could be a bad thermostat??
 
try re bleeding it when you have about a hour. When you revved it up you probably sucked in a even bigger air bubble. do exactly what haswesly said and don't rev the engine, if you still have a problem when its bleed we will go from there.
 
try re bleeding it when you have about a hour. When you revved it up you probably sucked in a even bigger air bubble. do exactly what haswesly said and don't rev the engine, if you still have a problem when its bleed we will go from there.

ok im gonna bleed in now and try to let it run ill check back...

ok so i bled the system and started the engine, coolant started overflowing through the thermostat from about 190-210 degrees and then at 210 it started flowing normally and it is holding a temp of about 210 for like 10 minutes... so u think that was the problem???? air in the system???
 
Don't understand holding temp for 10 minutes then what? Does it begin to rise again?

sry should have been more specific... but problem is definitely not solved. It was holding temp fine while it was idling but as soon as i tried to drive it it sent right to 225+ and i could hear a bubbling in the coolant line from the water pipe to the OFH and the hose has a hole in in now because it is leaking coolant everywhere from there... i think my OFH o ring is bad anyways so im going to replace everything with all new lines and hopefully that will fix the issue.
 
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