At idle 2005 Elantra temp guage goes to cold using heater blower

10

Asked by Jan 03, 2015 at 10:48 AM about the 2005 Hyundai Elantra GT Hatchback

Question type: Maintenance & Repair

After having a remote starter installed I have been chasing for a reason why the
temperature guage AND heater go/stay cold at idle. I have replaced the water
pump,radiator and hoses,and thermostat. Recently I have figured out that if the heater
fan is on low or off the temperature guage will come up to or close to normal operating
temperature when at idle.Turn the heater fan back on again (higher than low) and
literally watch the guage drop back down to cold again along with the temp inside the
car.With ANY higher rpm's above idle this problem does not exist.

12 Answers

10

Addendum: I did purchase a bleeder system/funnel and made sure to get all the air out of the coolant system!

33,675

It sounds like your thermostat is faulty. It's like it's stuck in the open position and not letting the coolant reach 180 degrees. You also may have an air bubble in your cooling system. When you replaced everything did you buy an air bleed kit to remove all air within the system? If not, I would try that first.

1 out of 1 people think this is helpful.
33,675

Oh, okay, you submitted your addendum as I was writing my response. When your temp is up into the normal range, squeeze your radiator hose and see if it's got pressure. If it's soft, your thermostat is stuck open.

10

I have recently felt the upper hose while the engine is hot,and surprised to see how "Rock Hard" it feels.I thought it was so hard that it could burst! I pointed this out to the mec and his response was that it was to be expected.

1 out of 1 people think this is helpful.
33,675

The only other thing I can think of is when you turn your heat to the ON position, the valve that lets the hot fluid into the heater core is not fully opening. Look for the two hoses that go into your fire wall. Is there a valve right there that you can see? If so, have someone turn on the heat and watch it to see if it moves. This would explain why you lose heat in the car, but not why your engine temp gauge would fall also. Unless you also have a bad engine temp sensor.

10

Mine can take up to twenty minutes for the temp gauge to even rise to the edge of the 'C' at idle when the temp is under 10 degrees. It warms up better once its on the road, but without the warmup it can take ten miles at 55 to get any warm air from the blower at all. This is not a 70's Ford or Chevy. Hyundai's have aluminum engines that naturally run cooler and being much more efficient don't waste as much energy in heat loss an the older cast iron types. In subzero temps, I often block the radiator with a bit of cardboard. I recommend a good winter synthetic oil, a sump heater and just what you're doing, letting it warm up a bit. Just don't expect comfort or defrosted windshields unless you install an electric cabin heater/defroster.

10

Again I want to reiterate that if I leave the fan OFF(blower for the interior heat) the guage comes up to a normal expected temperature "EVEN AT IDLE". When I get into the car and the guage has risen to an expected range, I can then turn the fan ON and the heat blows out nice and hot! It's ONLY when I have the interior fan set to the ON position that the temperature guage does not move. In that case the guage has not moved and there is no heat anywhere in the car and no heat built up in the coolant !Please remember that leaving the fan ON or OFF is done the night before so I can use the remote starter in the morning!

33,675

According to Quickdraw, it takes forever to warm up unless you are flying down the interstate. I believe what you are saying is that since you have installed the auto start, the heat is almost no existent. If what Quickdraw said is true, that these engines cool much quicker than the old cast iron ones, if you are turning on the fan at the same time you start the engine, then yes, it will never warm up. Try not turning on the auto start. Get up like you used to do, start the car, and let it warm up like it did prior to you getting the auto start installed. If you find that things are back to normal, then all the money you just spent on an auto start is essentially worthless. It's no fault of yours...just a car that is not meant to have an auto start due to the fact that it runs cooler than most cars........

10

Then the coolant has frozen. The fan position may be a red herring. Get a tester and check your antifreeze strength.

10

You might also want to check for bubbles at the radiator cap too. Sometimes aluminum heads get spongy or a head gasket can leak high pressure exhaust gasses into the coolant. It is occasionally an intermittent problem, based on temperature driven contraction and expansion of the head verses the top deck. This pressure leak creates a big high pressure bubble in the water jacket or return hose where the temp gauge pick up is and prevents the water pump from doing its job or the gauge from registering. There will be odd discolorations on the rad cap and little bubbles popping up, with smoke. Sometimes the overflow cap pops loose all the time and you wonder why. I had this happen on a 3 cylinder Chevy sprint and cold retorquing the head cured it. Look for simple first. Are you sure that the coolant is actually full? CHECK! You have to tip it in slow once its hot, so the jacket fills when the thermostat is open. You might have some debris in the hose defective new hose or collapsed rubber from the old hoses that randomly plug things up. That's why you flush. Are the hoses properly moulded or did you kink one trying to go cheap? You might have two things happening at once, like a damaged or wrongly modified temperature pick up, Stay calm and think logically. Did any of this temperature madness happen before the start gizmo got strapped on? What did they tinker with? What wires did they accidentally cut and scotch tape back together? Splices? Most of those guys aren't so smart. Does the heater box changeover baffle switch to hot based on a computer input telling it that every thing is hot now? Crack that radiator cap and see if coolant is flowing, stick your finger in the coolant when its saying that everything is cold after its been idling. Assume nothing. Maybe your new water pump is bad.

1 out of 1 people think this is helpful.
56,865

Double check the thermostat. It should be a 195°F one and be tightly closed when cold. HTH. -Jim

I and another 2005 elantra owner I know had a faulty thermostat issue that sounds exactly like this.

Your Answer

Add photo

Related Questions

Elantra

Looking for a Used Elantra in your area?

CarGurus has 53,087 nationwide Elantra listings starting at $895.

ZIP:

Search Hyundai Elantra Questions

Hyundai Elantra Experts

#1 pittgirl
pittgirl
Reputation 1,930
#2 Carrie Shelton
Carrie Shelton
Reputation 1,350
#3 tenspeed
tenspeed
Reputation 990
View All

Related Models For Sale

Used Hyundai Sonata
979 Great Deals out of 50,083 listings starting at $700
Used Honda Civic
1,142 Great Deals out of 67,876 listings starting at $1,500
Used Toyota Corolla
1,446 Great Deals out of 70,092 listings starting at $988
Used Honda Accord
1,244 Great Deals out of 79,083 listings starting at $969
Used Toyota Camry
1,510 Great Deals out of 101,222 listings starting at $700
Used Nissan Altima
1,361 Great Deals out of 86,082 listings starting at $1,795
Used Hyundai Accent
290 Great Deals out of 12,969 listings starting at $998
Used Kia Optima
578 Great Deals out of 30,674 listings starting at $1,250
Used Mazda MAZDA3
482 Great Deals out of 27,903 listings starting at $1,200
Used Ford Focus
1,251 Great Deals out of 60,886 listings starting at $1,395
Used Nissan Sentra
800 Great Deals out of 54,036 listings starting at $2,000
Used Ford Fusion
1,255 Great Deals out of 74,154 listings starting at $1,295

Used Cars For Sale

2017 Hyundai Elantra For Sale
54 Great Deals out of 35,759 listings starting at $9,556
2016 Hyundai Elantra For Sale
113 Great Deals out of 2,595 listings starting at $8,350
2015 Hyundai Elantra For Sale
162 Great Deals out of 2,681 listings starting at $7,995
2014 Hyundai Elantra For Sale
81 Great Deals out of 1,566 listings starting at $7,980
2013 Hyundai Elantra For Sale
354 Great Deals out of 5,546 listings starting at $5,980