Hyundai Elantra Forum banner

No heat while at idle

26K views 12 replies 12 participants last post by  Irene Pierce 
#1 ·
My car does not produce heat while at idle, if I shift into nutural and rev it to 1500rpm the heat is fine, also the heat is fine while driving. I have read some of the forums and found that the issue might be due to low coolant or a water pump issue, is there any way to tell which one is the problem?
 
#4 ·
could be neither. after i added weather stripping to the back of the hood, where it comes with some from the factory, i seem to have fixed the problem.

seems like all the cold freezing air getting into the engine bay down the firewall was causing the heater core lines to get quite cold, i no longer seem to have the issue of cold air at idle.
 
#5 ·
Logically that doesn't really make much sense Pete. The cold air isn't going to be enough to cool down the ~190* coolant going through the heater core.
 
#6 ·
i dont get it either man. why has this happened in any past winters? i dont know how to explain it.

but i bought some weather stripping from advance, n put it where the oem would b under the back of the hood. and i seem to be getting normal heat at idle again.

dont know man. im just sharing what ive done.
 
#8 ·
This is almost definitely due to a problem with the heater core not getting enough or any coolant flow through it. You could have a clogged heater core, air pocket, or not enough coolant. Since heater cores are designed to be bypassed if they clog the engine will still run at a normal temperature but you won't have any heat.

Try disconnecting the heater core lines and flushing water through it. Your car is only a 2005 so I can't see how the core could be clogged but anything is possible.

Did anyone add Dexcool or any type of "non green" coolant to the system?
 
#9 ·
I'm kinda new at this so I hope it's ok to post to an old thread and hope someone will read this.
I've had this same problem lately. Replaced the thermostat today and not sure the problem is fixed. My wife mostly uses the car and I'm sure she will let me know tomorrow. Is it possible my heater core is clogged? I don't have any coolant leaking. It's a 2002 Elantra with 200K miles.. Thanks for any input.
Dan O
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top