# No heat at idle? **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [December 29, 2011, 5:35pm UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411 "2011-12-29T17:35:04Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![mechanicalmadness](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/mechanicalmadness/32/5022_2.png) [@mechanicalmadness](https://forums.speedlife.net/u/mechanicalmadness)\ **Post date:** [December 29, 2011, 8:41pm UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/21 "2011-12-29T20:41:05Z")
> [@Carnut](#): > > If the thermostat was stuck open in this weather this engine would never heat up, ever. Not necessarily. If there is no airflow past the rad the slow coolant flow wouldnt provide much thermal transfer to atmosphere via the rad. Fry. Not sure how your vehicle is set up. Mine actually had a bleed hole (designed like this by audi I can’t make this ghetto shit up) drilled into the heater core outlet hose. The procedure is to actually undo the hose clamp. Start the engine and rev it to 3k while you pull the hose out so that the heater core tube clears the hole in the hose. Once the hole clears the tube you would hear a hiss followed shortly by bubbles then cooland. After which you push the hose on all the way and tighten the clamp. Bam! Heat is good. Older Audi/VW used to have actual bleed ports moulded into the coolant hoses where all you had to do was loosen a screw then re tighten when coolant flows out. I guess the new method is cheaper. A basic rule of thumb though. Find the highest point of the cooling system and start bleeding from there. Just make sure your coolant is topped off. I thought you were an engineer? Shouldn’t you know this 😉 ---------- Post added at 11:41 PM ---------- Previous post was at 11:34 PM ---------- > [@Fry](#): > > OK cool. Rad cap or overflow tank cap? If your overflow tank has a pressure cap on it and thats where you fill your cooling system from then the overflow tank cap. If you fill your cooling system from the rad then the radiator cap. Keep in mind that your rad cap may be actually lower then your highest level of coolant(make sense) in which case you will have to get creative. ---
**Author:** ![Carnut](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/carnut/32/7590_2.png) [@Carnut](https://forums.speedlife.net/u/Carnut)\ **Post date:** [December 29, 2011, 8:46pm UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/22 "2011-12-29T20:46:58Z")
> [@Fry](#): > > OK cool. Rad cap or overflow tank cap? Rad cap if that is your primary pressure cap. If there is no pressure cap on your overflow ignore it. Just make sure you top it off to the proper level when done. ---------- Post added at 11:46 PM ---------- Previous post was at 11:44 PM ---------- > [@mechanicalmadness](#): > > Not necessarily. If there is no airflow past the rad the slow coolant flow wouldnt provide much thermal transfer to atmosphere via the rad Sure that _could_ happen, but, how likely do you really think that he’d have a stuck open thermostat and a blocked off rad on a stock xterra? Probably not likely. Your cooling system does not have a bleed hole as per the factory service manual, bleed as I stated earlier, to make it easier get a lisle spill free funnel set. ---
**Author:** ![ultradriver10000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ultradriver10000/32/7397_2.png) [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)\ **Post date:** [December 29, 2011, 9:01pm UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/23 "2011-12-29T21:01:18Z")
When ever I’ve had a stat stuck open the only time the car would get heat was when it was parked. No real airflow would allow it to get up to temp but it would take forever then once I’d start driving it would go ice cold. I’d agree with Carnut that it is probably the fluid, no other real reason, unless there is some wacky electrical controller somehow integrated into the system. I’d swap in the resister while your at it fan speeds not working always bugs me haha. ---
**Author:** ![mechanicalmadness](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/mechanicalmadness/32/5022_2.png) [@mechanicalmadness](https://forums.speedlife.net/u/mechanicalmadness)\ **Post date:** [December 29, 2011, 9:01pm UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/24 "2011-12-29T21:01:23Z")
I never said anything about a clogged rad. Just no airflow ie idling in the driveway while warming the truck up in the morning. Again I don’t claim to know how Frys truck is set up. But from previous experience I can with full confidence say that just because there isn’t a port to bleed from doesn’t mean that there shouldn’t be one. Not saying that he needs to install one. But let’s face it. Sometimes things aren’t built the way they should be. Thus the need to bleed a system that “doesn’t need” bleeding. ---
**Author:** ![ubengineering](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ubengineering/32/5171_2.png) [@ubengineering](https://forums.speedlife.net/u/ubengineering)\ **Post date:** [December 29, 2011, 9:52pm UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/25 "2011-12-29T21:52:55Z")
run with cap off =D ---
**Author:** ![airhead](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/airhead/32/7471_2.png) [@airhead](https://forums.speedlife.net/u/airhead)\ **Post date:** [December 29, 2011, 11:42pm UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/26 "2011-12-29T23:42:29Z")
I just had the exact same issue with my Jeep. My heat varied by speed and then quit completely. Everyone was saying air in the system, and they were right. It was the damn radiator cap that caused it all, a $5 part and it’s been perfect ever since. ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [December 30, 2011, 5:20am UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/27 "2011-12-30T05:20:06Z")
Sure enough. A few farts out of the overflow tank cap and I’ve got heat at idle again. Amazing how little air made the difference. Thanks for the tip on the rad cap. If it keeps coming back I’ll give that a try. ---
**Author:** ![Carnut](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/carnut/32/7590_2.png) [@Carnut](https://forums.speedlife.net/u/Carnut)\ **Post date:** [December 30, 2011, 6:03am UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/28 "2011-12-30T06:03:04Z")
If it comes back you have an external leak or your engine is ingesting it and it’s either ending up in the oil or burned in the cylinders. Low coolant is a symptom. ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [December 30, 2011, 6:07am UTC](https://forums.speedlife.net/t/no-heat-at-idle/219411/29 "2011-12-30T06:07:59Z")
> [@mechanicalmadness](#): > > A basic rule of thumb though. Find the highest point of the cooling system and start bleeding from there. Just make sure your coolant is topped off. I thought you were an engineer? Shouldn’t you know this 😉 lol one would think. Not like I design high point vents into my cooling water systems or anything… I’ll use sleep deprivation and beer as my excuse. :tup: ---------- Post added at 09:07 AM ---------- Previous post was at 09:05 AM ---------- > [@Carnut](#): > > If it comes back you have an external leak or your engine is ingesting it and it’s either ending up in the oil or burned in the cylinders. Low coolant is a symptom. Thanks. I’ll watch for that. As of now the level is fine so hopefully my head gasket is good. [Previous page](https://forums.speedlife.net/t/no-heat-at-idle/219411.md?page=1)