# Surging heat- wtf? **URL:** \ **Category:** Shift518 Automotive\ **Created:** [October 28, 2008, 3:30pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836 "2008-10-28T15:30:38Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![PJB](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pjb/32/6389_2.png) [@PJB](https://forums.speedlife.net/u/PJB)\ **Post date:** [October 28, 2008, 3:30pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/1 "2008-10-28T15:30:38Z")
I just went out with my '05 Elantra and noticed that the heater kept blowing cold, then hot, then cold again like the heat is surging on and off but the blower is still working fine. When its hot its like it should be but then it turns ice cold. A few times when it was blowing cold the temp gauge went up above the middle like its never done before (always stays below the middle) and when it did that the heat was warm again. I cant figure out what the deal with that is since the coolant is obviously warmed up because the heat will blow hot. ---
**Author:** ![tdi\_logik](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tdi_logik/32/6310_2.png) [@tdi\_logik](https://forums.speedlife.net/u/tdi_logik)\ **Post date:** [October 28, 2008, 3:33pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/2 "2008-10-28T15:33:45Z")
americas best warranty 10yr 100k warranty. get it taken care of, oh i have you’re rachect strap sitting here in my garage, don’t worery. ---
**Author:** ![PJB](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pjb/32/6389_2.png) [@PJB](https://forums.speedlife.net/u/PJB)\ **Post date:** [October 28, 2008, 3:38pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/3 "2008-10-28T15:38:56Z")
That warranty is bullshit and probably wont cover it. Maybe this snow shit will be gone by the weekend and Ill see you at the lot. Supposed to be in the 50’s this week. ---
**Author:** ![tdi\_logik](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tdi_logik/32/6310_2.png) [@tdi\_logik](https://forums.speedlife.net/u/tdi_logik)\ **Post date:** [October 28, 2008, 3:40pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/4 "2008-10-28T15:40:02Z")
> [@PJB](#): > > That warranty is bullshit and probably wont cover it. > Maybe this snow shit will be gone by the weekend and Ill see you at the lot. Supposed to be in the 50’s this week. ooooo, idk about friday, its haloween. :ohnoes ---
**Author:** ![tdi\_logik](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tdi_logik/32/6310_2.png) [@tdi\_logik](https://forums.speedlife.net/u/tdi_logik)\ **Post date:** [October 28, 2008, 3:41pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/5 "2008-10-28T15:41:28Z")
try the warranty. it will work. guarnteed. if ya see big billy tell him peter sent ya. ---
**Author:** ![PJB](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pjb/32/6389_2.png) [@PJB](https://forums.speedlife.net/u/PJB)\ **Post date:** [October 28, 2008, 3:42pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/6 "2008-10-28T15:42:22Z")
> [@30r\_logik](#): > > ooooo, idk about friday, its haloween. :ohnoes I dont know about you but I outgrew that many years ago. > [@30r\_logik](#): > > try the warranty. it will work. guarnteed. if ya see big billy tell him peter sent ya. Ive tried it for other shit and it wasnt worth my time trying. And Im sure Billy knows who you are too. ---
**Author:** ![tdi\_logik](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tdi_logik/32/6310_2.png) [@tdi\_logik](https://forums.speedlife.net/u/tdi_logik)\ **Post date:** [October 28, 2008, 3:49pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/7 "2008-10-28T15:49:11Z")
> [@PJB](#): > > I dont know about you but I outgrew that many years ago. > Ive tried it for other shit and it wasnt worth my time trying. And Im sure Billy knows who you are too. oh. i’m not goin trik or treatinnnn ---
**Author:** ![PJB](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pjb/32/6389_2.png) [@PJB](https://forums.speedlife.net/u/PJB)\ **Post date:** [October 28, 2008, 3:51pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/8 "2008-10-28T15:51:41Z")
> [@30r\_logik](#): > > oh. i’m not goin trik or treatinnnn shaving cream then? ---
**Author:** ![tdi\_logik](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tdi_logik/32/6310_2.png) [@tdi\_logik](https://forums.speedlife.net/u/tdi_logik)\ **Post date:** [October 28, 2008, 3:52pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/9 "2008-10-28T15:52:18Z")
> [@PJB](#): > > shaving cream then? nope. going to st.rose then idk where after :nod ---
**Author:** ![n\_cole](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/n_cole/32/6382_2.png) [@n\_cole](https://forums.speedlife.net/u/n_cole)\ **Post date:** [October 28, 2008, 4:04pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/10 "2008-10-28T16:04:56Z")
Your car is drunk Paul. ---
**Author:** ![PJB](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pjb/32/6389_2.png) [@PJB](https://forums.speedlife.net/u/PJB)\ **Post date:** [October 28, 2008, 4:06pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/11 "2008-10-28T16:06:55Z")
> [@n!cole](#): > > Your car is drunk Paul. I was the one that drank beer, not the car as far as I know. Unless you were sneaking my car beer while I was in Otooles. ---
**Author:** ![n\_cole](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/n_cole/32/6382_2.png) [@n\_cole](https://forums.speedlife.net/u/n_cole)\ **Post date:** [October 28, 2008, 4:08pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/12 "2008-10-28T16:08:01Z")
:ninja ---
**Author:** ![PJB](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pjb/32/6389_2.png) [@PJB](https://forums.speedlife.net/u/PJB)\ **Post date:** [October 28, 2008, 4:09pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/13 "2008-10-28T16:09:47Z")
I just hope it wasnt Bud. I dont want my car puking later. ---
**Author:** ![n\_cole](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/n_cole/32/6382_2.png) [@n\_cole](https://forums.speedlife.net/u/n_cole)\ **Post date:** [October 28, 2008, 4:10pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/14 "2008-10-28T16:10:41Z")
It was Beast. Your car is fucked. :tong ---
**Author:** ![Alpine](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@Alpine](https://forums.speedlife.net/u/Alpine)\ **Post date:** [October 28, 2008, 4:13pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/15 "2008-10-28T16:13:37Z")
Heater core? ---
**Author:** ![n\_cole](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/n_cole/32/6382_2.png) [@n\_cole](https://forums.speedlife.net/u/n_cole)\ **Post date:** [October 28, 2008, 4:14pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/16 "2008-10-28T16:14:50Z")
Does it smell funny and leave a greasy looking schmutz on the windsheild? Cause that’s what happened to Joe’s truck when his heater core went. ---
**Author:** ![PJB](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pjb/32/6389_2.png) [@PJB](https://forums.speedlife.net/u/PJB)\ **Post date:** [October 28, 2008, 4:17pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/17 "2008-10-28T16:17:42Z")
> [@n!cole](#): > > It was Beast. Your car is fucked. :tong I cant say Ive been drunk off that before so I dont know what to look out for. > [@n!cole](#): > > Does it smell funny and leave a greasy looking schmutz on the windsheild? Cause that’s what happened to Joe’s truck when his heater core went. No, not at all. I know what a blown heater core is like because it happened in one of my old trucks and my Mustang. The blower works and gets the fog off the windshield without leaving anything behind. ---
**Author:** ![LKSi](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lksi/32/6316_2.png) [@LKSi](https://forums.speedlife.net/u/LKSi)\ **Post date:** [October 28, 2008, 4:24pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/18 "2008-10-28T16:24:42Z")
Alright, I checked it out for you… and here are possible causes of erratic heat on a 2005 Hyundai Elantra Low Coolant Level Incorrect thermostat Restricted coolant flow through core Heater hoses plugged Misadjusted control cable Sticking heater control valve Vacuum hose leaking Vacuum hose blocked Vacuum motors inoperative Blocked air inlet Inoperative heater blower motor Oil residue on heater core fins Dirt on heater core fins Temperature door stuck open I think you’ll be able to narrow it down… good luck ---
**Author:** ![n\_cole](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/n_cole/32/6382_2.png) [@n\_cole](https://forums.speedlife.net/u/n_cole)\ **Post date:** [October 28, 2008, 4:25pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/19 "2008-10-28T16:25:52Z")
:lol Better start doing some guess and check. ---
**Author:** ![PJB](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/pjb/32/6389_2.png) [@PJB](https://forums.speedlife.net/u/PJB)\ **Post date:** [October 28, 2008, 4:27pm UTC](https://forums.speedlife.net/t/surging-heat-wtf/239836/20 "2008-10-28T16:27:18Z")
Yeah, that narrows it down just a bit. Just replace the entire heating system and itll be ok. Its the original thermostat so definately not the wrong one. [Next page](https://forums.speedlife.net/t/surging-heat-wtf/239836.md?page=2)