Surging heat- wtf?

Shift518 Automotive
1

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.

2

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.

3

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.

4

ooooo, idk about friday, its haloween. :ohnoes

5

try the warranty. it will work. guarnteed. if ya see big billy tell him peter sent ya.

6

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.

7

oh. i’m not goin trik or treatinnnn

8

shaving cream then?

9

nope. going to st.rose then idk where after :nod

10

Your car is drunk Paul.

11

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.

12

:ninja

13

I just hope it wasnt Bud. I dont want my car puking later.

14

It was Beast. Your car is fucked. :tong

15

Heater core?

16

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.

17

I cant say Ive been drunk off that before so I dont know what to look out for.

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.

18

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

19

:lol

Better start doing some guess and check.

20

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.