'05 Elantra-- poor heater output at idle-

[Lapham3]

Hi there-I'm a new guy with this Hyundai. 2nd owner of a pretty well dealer maintained 80k mile GT hatch with the 2.0 engine. All is well excepting that it doesn't provide much heat until engine speeds are increased above idle=which isn't really a huge problem but in cold (today is around zero) weather it's nice to start it up and let it warm up a while before getting in to head out. As soon as engine speed is raised up to around 1000-1200 rpm or I start driving, heat is just fine. Coolant-fan-thermostat gauge all seem fine. All I can think of are worn/eroded vanes in the water pump-and too much coolant is bypassing? Not something I've experienced before on a vehicle-thanks!-Dan Mpls. Mn.

 

[eljefino]

You're on the right track. Could be an air bubble. Get under the hood, feel the hoses, and blip the throttle to get a yet better feel.

 

[Lapham3]

I should have mentioned that the rad cap and hoses hold pressure-rad hoses/rad heat up with thermo opening and I've cracked the bleed valve and get coolant-no air as should be. Also, The water pump appears OE as this dealer doesn't automatically replace it with the timming belt that was done 20k miles ago

 

[dishdude]

This symptom is almost always caused by low coolant level. In addition to the overflow bottle, check the level in the radiator when the engine is cold.

 

[renegade_987]

Originally Posted By: dishdude
This symptom is almost always caused by low coolant level. In addition to the overflow bottle, check the level in the radiator when the engine is cold.


+1

 

[mclasser]

My 05 Elantra had this exact same problem before I sold it. When you accelerate, do you hear a whooshing noise that sounds like moving water? Even if you don't, you probably have air in the cooling system. Check the radiator and overflow tank coolant levels. The overflow tank is hard to read so shining a flashlight at it helps. Also check for leaks and bleed the system by jacking up the front end, removing the radiator cap and running the engine until the fans cycle on/off at least 3 times. Revving the engine via the throttle cable will help the fans come on quicker than when letting the car just sit there and idle. All the while, make sure the heater is off but turned all the way to red so coolant moves through the heater core as well.

 

[Carbuff]

Originally Posted By: mclasser
Revving the engine via the throttle cable will help the fans come on quicker than when letting the car just sit there and idle.


Also, the increased velocity of the coolant will drive out any air pockets.

I always run my engines to redline once or twice the week following a coolant change...same reasoning.

 

[Vikas]

But wouldn't air bubble eventually be replaced with the fluid after many cycles?

 

[bmod305]

Not always an air bubble or low coolant. Some vehicles have low coolant circulation at idle. Not enough warm coolant flows thru the core at idle. I had a 99 Montana with the same problem. GM had a TSB on it. You may want to check with your dealer to see if they have anything similar.

Dave

 

[The_Eric]

We have an 01 Elantra (same engine) and have a similar deal. I just figured that between the low water pump speed and low engine output (heat) the HVAC suffers some. The air is still warm(ish) but doesn't have that nice cozy warm feel to it.

These cars have a bit cooler stat in them anyway. Mine has an 82c (179*F) and I think the newer ones are 85c (185*F).

I really doubt there is an air pocket there, and I doubt even more that there is an issue with the pump's impeller. If the coolant level is fine and there is pressure in the system when warm, I wouldn't worry too much about it. You could always pick up a new stat and gasket and give it a whirl. I recommend buying these from the dealer- there is a difference.

 

[Lapham3]

Thanks guys for all the inputs. Coolant levels are fine and I've had other cars that can be a bit of a pain burping air out, so that's not the problem either. I wonder what the GM bulletin had to say as to the 'fix' on those vans? I guess I'm thinking along Eric's thoughts-and I've had other all aluminum engines that seem to shed heat about as fast as they make it-synthtic oils and light to no loads at idle coupled with Minnesota winter temps make it worse. I can live with it-just don't like it so much! Of course the wife's cast iron engined Jeep will cook you out-Dan

 

[Trav]

I have a Subaru all aluminum engine that will make you check if your socks are not on fire.
Iron or aluminum engines are both capable of generating enough heat.

 

[Pop_Rivit]

I have a 2006 Elantra, and even at idle the heater will blow extremely hot air once the engine is warmed up. It's extremely quick to warm up even in cold weather-it's normally close to 180 degrees when I stop at the stop sign 2 miles from the house.

I'd start with the basics on yours-when was the last time you flushed the cooling system including the heater core? Does it maintain coolant temperature when idling? Or does the coolant temperature drop when at a stop light? I have an ultra gauge on mine and it stays at 182 when idling, however I have a Dodge pickup that will drop coolant temperature at idle in cold weather, and the heater temperature will start falling too. I insulated the heater lines and added a winter front to solve the issue.

 

[bmod305]

GM's fix with an aux coolant pump on one of the heater hoses. My own fix was to put the van in neutral at a stoplight and increase the rpm by 500. Worked great but kind of a pain in stop and go.

Dave