my heater doesnt blow hot

[bcrosby]

What would make my heater not blow hot? Now that its getting cold out ive noticed that my heater just doesnt blow hot. Could it be the thermostat? Any ideas would be appriciated.

 

[blackGSX2g]

My guess is either low coolant and/or bad thermostat. Flush in some new coolant with an OEM (if possible) thermostat and see if that fixes the problem. When you are adding coolant, make sure to burp the system of all air bubbles. Once its full, leave the cap off and start up the car to double check that coolant is flowing to rule out a water pump failure or a major clog in the system.

Also make sure your not loosing it through a burst or loose hose. The first thing I notice (if its winter) when I've got a major coolant leak is an immediate loss of heat.

If these solutions don't work, post back and we'll take it from there.

 

[98eclipseRS]

My guess is either low coolant and/or bad thermostat. Flush in some new coolant with an OEM (if possible) thermostat and see if that fixes the problem. When you are adding coolant, make sure to burp the system of all air bubbles. Once its full, leave the cap off and start up the car to double check that coolant is flowing to rule out a water pump failure or a major clog in the system.

Also make sure your not loosing it through a burst or loose hose. The first thing I notice (if its winter) when I've got a major coolant leak is an immediate loss of heat.

If these solutions don't work, post back and we'll take it from there.

Couldn't have said it better myself.

 

[NitrousPete]

Low on coolant would actually cause a low temerature gauge reading, since the sensor is mounted on the T-stat housing, thus at the top of the cooling system. Low coolant would likely read low or not at all since there would be no coolant passing over it. Chances are your T-stat is stuck closed, therefor not allowing circulation. The small bypass hole in the disk on the T-stat is probably passing enough coolant to show a hot reading on the sensor as hot coolant from behing the T-stat is creeping by and warming the sensor (this is what that hole is designed to do).

Be careful driving the car like that, without circulation the motor is actually running very hot, and you're looking at detonation problems from hot valves or worse, head gasket or other mechanical damage.

Another thing you can do is get the car up to operating temperature and, without loosing an arm in any moving parts, grab the top and bottom radiator hose. If the top hose is staying pretty much COLD and the bottom hose is hot, then change your thermostat.

 

[blackGSX2g]

Low on coolant would actually cause a low temerature gauge reading, since the sensor is mounted on the T-stat housing, thus at the top of the cooling system. Low coolant would likely read low or not at all since there would be no coolant passing over it.

The sensor is just a temperature probe. It will indicate the relative temperature of whatever is in the water neck; be it water, air, or steam.

If you are losing coolant, that means there is probably a pressure loss somewhere in the system. A loss of pressure means water boils at a lower temperature, so the little water you have left in your system begins to boil and turn to steam as your motor begins the tragic downfall of overheating. The steam/boiling water mix that has been created is then registered as a high temperature on your probe, thus making your temperature needle rise.

 

[NitrousPete]

Possible I guess, but most of the cases I've seen in the past where coolant was low, there was a low temp reading on the gauge. A high water temp and lack of heat generally indicates a circulation problem.

Also, steam typicly will not go above 212*F unless it is in a pressurized system, and a leaky system would not be an environment condusive to pressure obviously. Also, in a sealed system under pressure, the boiling point of water is increased, and although the temp gague in a DSM is only an idiot gage and not an actual numeric temp gauge, it sounds like the temperature of his coolant is significantly higher than normal. These are the reasons I feel his problem is related to a blockage and not a low system.

I guess we'll know when he checks his antifreeze

 

[blackGSX2g]

Also, steam typicly will not go above 212*F unless it is in a pressurized system, and a leaky system would not be an environment condusive to pressure obviously. Also, in a sealed system under pressure, the boiling point of water is increased, and although the temp gague in a DSM is only an idiot gage and not an actual numeric temp gauge, it sounds like the temperature of his coolant is significantly higher than normal.

Steam at atmosphere will not go above 212*F, but if he had a leak large enough to bleed off all possible system pressure, chances are he would not be asking why he is overheating. That is usually a case where a radiator hose has completely burst and spewed out enough coolant for almost any motorist to see.

My stock gauge will begin to rise on my car at anything past 225-230*F or so, meaning that as long as he has over 6psi of pressure the gauge will pick up steam temperature as overheating. I don't mean to say that his cooling system is FULL of steam, I'm just saying its more than likely an ingredient in it.

If his problem is more complex such as a headgasket failure, the burst in the gasket will cause cylinder pressure to leak into the cooling system causing more pressure. I ran into this problem when my headgasket went. All of my little coolant lines began to burst every time I drove it causing massive headaches and many purchases of rubber hosing and coolant until I could fix the problem.

But yes, when he posts back more information we can solve the problem better.

 

[Flybiyou]

I am having the same problem with my car. Did you find what it is?

 

[davnsam6]

as stated before change the coolant ,but before you refill radiator pull the heater lines from your heater core and flush it. i have personally seen heater cores pluged with junk. thats the second thing i always check when someone complains of no heat . the first thing is coolant and thermostat.

 

[packinkimber45]

hi, I was wondering how hard would it be to get the heater back up and running? couldnt really find anything in search. looks like on my motor, previous owner took heater hoses out and just looped one hose on the engine to the old connections on motor. pipes off of heater core looks pretty bent and deformed in engine bay, is there anything else that I would need to do other than just reconnecting the two hoses again to the heater core to make the heater work again? thanks.

 

[95TalonOwner]

I would say flush out the heater core, then reconnect the pipes and see what happens.

 

[packinkimber45]

would this require me to take the core out of the vehicle?

 

[Newlogics]

hi, I was wondering how hard would it be to get the heater back up and running? couldnt really find anything in search. looks like on my motor, previous owner took heater hoses out and just looped one hose on the engine to the old connections on motor. pipes off of heater core looks pretty bent and deformed in engine bay, is there anything else that I would need to do other than just reconnecting the two hoses again to the heater core to make the heater work again? thanks.

The question you have to ask yourself, is why did previous owner disconnect heater?
People don't just stuff like that for no reason. My guess is that core has been leaking. Be watchfull when you reconnect, so you don't end up with a puddle of coolant inside your car.

First thing I would do, is to cap one end off, and pressurize the other one to 13psi and see if it holds pressure.

 

[packinkimber45]

that's what I was wondering. why would you disconnect heater in Idaho.WTF is there anything I should do, like checking anything... should I just take out core to see if it leaks? any other things I should be cautious about? I looked under the coolant cap and resirvoir and no coolant??? I dont know what exactly has been done to this car. thanks.

 

[Newlogics]

that's what I was wondering. why would you disconnect heater in Idaho.WTF is there anything I should do, like checking anything... should I just take out core to see if it leaks? any other things I should be cautious about? I looked under the coolant cap and resirvoir and no coolant??? I dont know what exactly has been done to this car. thanks.

Cap one end off, and connect some sort of pump to the other, pump it up to 13psi and make sure pressure stays solid.

 

[packinkimber45]

ok, thank you

 

[Pitman99505]

Ok so as the title says, my heater is not working, no matter what setting I put it on, nothing happens. Along with this problem, My car has been overheating. It overheats if I drive it a llittle ways or if it standing still. The two questions I have are:

1.) Is there a dirct relationship between my heater not working and the overheating? If so could someone explain the relationship to me. I have searched, but I still a little fuzzy on it.

2.) My upper radiator hose gets firm and hot, but it is almost too hot to touch. I was wondering if that is normal?

Thanks for in advance for any response.

 

[diablos991]

Most likely your thermostat is out. It is stuck and will not allow coolant to circulate.

That would explain why your upper heater hose is firm, and why coolant is not circulating through your heater core and causing your heater not to warm up.

 

[Pitman99505]

I have changed the thermo twice, is it possible the heater core could be blocked and therefore not causeing the tstat to open?

 

[20psi_GST]

Its your head gasket. Fill it up full of coolant/water and crank it and see if it goes down. If it goes down then its burning the coolant/water. You could see smoke or you could not. It might be burning straight out the exhuast (this most likely happens if your turbo is water cooled) and if it is you wont see any signs. But if its burning the coolant/water then its most like your head gasket.

 

[diablos991]

Yes, have your coolant flow tested, pressure tested, and powerflushed.

It wouldn't hurt to replace your radiator cap as well.

If your upper radiator hose is ballooning, replace that as well. (you wouldn't want it popping on you.

When was the last time that you changed your water pump?

 

[Ultimatedsm]

Test your thermostat out. Get some kind of pan and put some water in it. Put it on the stove, Or if you have some kind of propane lighter so you can do it in your garage (Make sure the garage is well vented). Put in some kind of temp gauge or anything that measures temp in the water and heat it up while the thermostat is in the water, keep watching your thermostat while it gets closer to it temps which makes it open (It should say on the thermostate). If it doesn't open at all, than you know there is a problem.

 

[diablos991]

Its your head gasket.

WTF Now that is jumping to conclusions. He should work on the little stuff before he just assummes that it is the head gasket.

If you are worried about the head gasket, a compression test never hurts.

 

[Ultimatedsm]

Yes, have your coolant flow tested, pressure tested, and powerflushed.

It wouldn't hurt to replace your radiator cap as well.

If your upper radiator hose is ballooning, replace that as well. (you wouldn't want it popping on you.

When was the last time that you changed your water pump?

I believe if the pump was defective, the upper radiator hose will never get firm because it won't get any coolant.

 

[Pitman99505]

Water pump was replaced 20k miles ago. I have started the car on a cold start with the radiator cap and I did not notice the fluid really moving. I thought that if the water pump was out the upper radiator hose would not get hot nor firm. Mine is quite hot, like I said almost too hot to touch.

 

[Ultimatedsm]

To rule out the headgasket, just simply do a compression test or test your rad fluid for oil.