# Coolant Boiling? **URL:** \ **Category:** SON240sx Automotive\ **Created:** [September 23, 2009, 11:06am UTC](https://forums.speedlife.net/t/coolant-boiling/128249 "2009-09-23T11:06:20Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![polishprince](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/polishprince/32/5690_2.png) [@polishprince](https://forums.speedlife.net/u/polishprince)\ **Post date:** [September 23, 2009, 11:06am UTC](https://forums.speedlife.net/t/coolant-boiling/128249/1 "2009-09-23T11:06:20Z")
I have been having this issue lately and cant seem to find an answer online. I had a coolant leak two weeks ago from a hose that split. Got it fixed. Then I noticed I had no heat and coolant spit out of my reservoir so I bled it to get the air out. Now lately I have noticed that I dont really get any heat until I get on the highway and sometimes when I get off the highway the heat seems to cool off again. I replaced the rad cap today and drove around. I got heat from city driving but when I got home, coolant was boiling in the reservoir again when I turned the car off. Its an sr, dual flex a lite fans (on all the time but I think only one is working now). Stock rad i believe. What should I do next? I was going to get that other fan to work and change the thermostat. ---
**Author:** ![Blue\_S13](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/blue_s13/32/5563_2.png) [@Blue\_S13](https://forums.speedlife.net/u/Blue_S13)\ **Post date:** [September 23, 2009, 11:17am UTC](https://forums.speedlife.net/t/coolant-boiling/128249/2 "2009-09-23T11:17:33Z")
Did you have the heat selector on full hot when you bled? I’ve seen that cause issues. Sounds like you have an air pocket in there still. ---
**Author:** ![FUNGC](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fungc/32/5539_2.png) [@FUNGC](https://forums.speedlife.net/u/FUNGC)\ **Post date:** [September 23, 2009, 12:27pm UTC](https://forums.speedlife.net/t/coolant-boiling/128249/3 "2009-09-23T12:27:03Z")
happened to a friend of mine. and his head gasket was blown. try searching nico, i believe thats where we found the answer. ---
**Author:** ![87s15lt1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/87s15lt1/32/5706_2.png) [@87s15lt1](https://forums.speedlife.net/u/87s15lt1)\ **Post date:** [September 23, 2009, 12:43pm UTC](https://forums.speedlife.net/t/coolant-boiling/128249/4 "2009-09-23T12:43:42Z")
thermostat ---
**Author:** ![polishprince](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/polishprince/32/5690_2.png) [@polishprince](https://forums.speedlife.net/u/polishprince)\ **Post date:** [September 23, 2009, 1:39pm UTC](https://forums.speedlife.net/t/coolant-boiling/128249/5 "2009-09-23T13:39:43Z")
I did have my heat on full when i bled. Thermostat is i think the way that i am going to go. I dont think its the head gasket because there is no oil/coolant mixing. I have seen that possibility discussed as well. ---
**Author:** ![DT\_racer](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@DT\_racer](https://forums.speedlife.net/u/DT_racer)\ **Post date:** [September 23, 2009, 7:01pm UTC](https://forums.speedlife.net/t/coolant-boiling/128249/6 "2009-09-23T19:01:37Z")
A head gasket can leak without putting oil into the antifreeze (combustion pressure from a cylinder pushing past the gasket into a water passage would cause bubbles/boiling in the system). I suggest getting a pressure test done on the system and go from there. ---
**Author:** ![polishprince](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/polishprince/32/5690_2.png) [@polishprince](https://forums.speedlife.net/u/polishprince)\ **Post date:** [September 24, 2009, 7:26am UTC](https://forums.speedlife.net/t/coolant-boiling/128249/7 "2009-09-24T07:26:51Z")
Here is where it gets funny… i changed the rad cap yesterday and today i drove to work and had the heat come on quick… no boiling when i got to work. 30 min drive. about 10 min road, 15 min highway, 5 min road… ---
**Author:** ![kollo](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/kollo/32/5661_2.png) [@kollo](https://forums.speedlife.net/u/kollo)\ **Post date:** [September 24, 2009, 8:19am UTC](https://forums.speedlife.net/t/coolant-boiling/128249/8 "2009-09-24T08:19:34Z")
a better rad wouldn`t hurt iether if you have stock ka when running sr but i`m think its the thermostat