No heat!

[toddmingnworld]

Anybody had to change out their heater core before? If so, how much did it cost and how much time was involved. Is it a time
consuming task see as my car blows out lukewarm air (not cold not warm) I wondering if my heater core is bad....

Anyone experienced this problem before as I'm being told that the heater valve could be clogged or I could have a bad vacuum line somewhere. Anyone who has run into this who could give me an idea on what I may beed to do on this issue will be appreciated...

Thanks,

Todd

 

[salvageV6]

3 hour job on a very cold winter day this year.

Mine leaked and totally fogged up the car.

Mine also worked MUCH better before the swap!

I used a brandy new GM stock part number heater core.

I wasn't impressed.

If it ain't leaking I doubt it's the core.

Check for proper hot water flow through the hoses first with the system operating.

 

[scottyb]

Are you sure the valve is opening all the way?
Mine does not. I have to pop the hood and give it a little tug for it to open up all the way, otherwise the heat is just "warm".
Next, make sure that the door under the dash is fuctioning properly and moving all the way to "heat". I've never been under there, so I don't know how this works/looks....

If these pieces function properly, then it may still may not be the core, but it is relatively easy to do. Post again if you get there.

Good luck.

 

[toddmingnworld]

It does not fog up the windows. I feel the heat around the
valve and the hoses but the heat does not make it into the car..
Just cool air is what comes out? Expensive job perhaps??

 

[toddmingnworld]

Scottyb,

I have fooled around with the valve and it moves around with
reasonable play...What symptoms are indicative of a bad heater
core? That is what I am trying to avoid.

 

[scottyb]

I have never seen one clog, but I guess it's possible. When the arm on the valve is up (open), are the pipes going into the core hot?

Typically, a bad heater core is a leaky one.

 

[Renthorin]

In theory the heater core can plug up just like a radiator. Is there a lot of 'goop' (technical term) in your radiator? If so it is also getting into the tubes of the heater core.

One thing to remember is if you run a 160 therm the car will never get as warm as it did stock, particulary in the winter.

My experience with this same problem was a faulty valve. They are cheap and easy to replace.....not so with the core.

 

[toddmingnworld]

No the radiator is pretty clean....I just want the car to be
warm as I want to drive it at night and also during the fall season..Does the valve usually go bad?

 

[V8killR4U]

same problem

Im experiencing a similar problem, the car heat used to work now it barely blows out luke warm air, if i out the heater on high it barely if any blows air. any suggestions? i thad worked the last time i ran it, im in MI so i need it!

 

[WakkoSS]

Heat? What for? I cranked my A/C today...not quite sure why you'd want to turn the heat on when it's 80 degrees outside.

 

[V8killR4U]

hahaha, were not so fortunate here in michigan, its like 24-25 degrees here and that a warm up fro where its been single digits negative windshields temps. If it hits hi 40's and sunny here people start droppin the ctopos on there convertables and start wearing shorts!

 

[Renthorin]

I don't know if the valves go bad but they do get harder to move as they age. They can also develop a leak and this prevents them from opening and closing fully.

One test is to remove the vac line and the valve should spring one way or the other.

Now, manually push the plunger all the way to the other end of its travel. Before you let go (it is spring loaded) put your finger over the tube that the vac line connects to. Let go of the valve keeping your finger over the vac line hole.

The valve door should not move. If it does.....it is bad.

If it doesn't, put the vac line back on and have someone move the temp controller from cold to hot and you should see the plunger on the valve move all the way it did like when you did it by hand.

 

[V8killR4U]

where is this vacuum line located? Is there a diagram i can refer too? Im new to gns and not really a mechanic but ill try it

 

[Renthorin]

If you find the valve (located up by the heater box where the two heater core lines go into the firewall) that is where the valve is located. There is a single hard plastic line connected to the valve.

That is the line to remove.

 

[Brian Mc]

Don't forget the mode door cold/hot

 

[Gbodynutt]

Have you checked the upper radiator hose? Is it hot along with the rest of the hoses? If not you could have a stuck thermostat. I've run into this on quite a few cars this winter. Blowing little or no heat, changed the thermostat and it blows nice hot air now.

Also check the operation of the cold hot door like mentioned above, along with the valve.

 

[SuperSix]

I had the opposite problem - valve looked great and operated well.. from the outside, pulled it out, entire center rotted out.. After taking it apart, it's entirely possible it can get stuck in either position. Pull it out and look at it, make sure the "gate" in the middle is rotating properly. It is just plastic in a very hostile environment.

When you need a new one, it's GM PART # 25523118
GM LIST: $40.35
OUR PRICE: $20.17

@
GMPartsDirect.com

 

[channer]

I agree with "Brian Mc".... check the mode door. If it's blowing the same constant air temp no matter if you move the temp control to cold or hot, that might be your problem. There's a plastic lever (you can see it if you "drop" the glove compartment door) that will break or snap off leaving that door in an open or close position. The car was constantly blowing hot air during the first summer I had the car.

And if that is not it, then it might be your heater valve because I've just changed my heater core (leak) and I still get the same warm air for the last 4 winters.


PS: SuperSix..... I guess those guys bidding on a new heater valve on ebay are being duped because they're bidding $25-30. I got outbid @ $25.

 

[BooBoo231cu]

I had good heat. Then my heater ore went, so I replaced it. Now I have no heat! I did eveything right, or not. It will be hot for a minute...then blow cold air. I also flushed the system, put in new hoses and a new heater water valve. I am so pissed! Could it be the vaccume line???

 

[channer]

There may still be air pockets in your system... I would let the car run with the rad cap off and let the coolant circulate to get rid of any air pockets.

it's a start, hope that helps.