heater not hot

my heater just isn't pushing out the hot weather it used to...is that a stuck t-stat?. i have a stock t-stat on a 2000 ls1

Turn it over to the red part.

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Originally Posted by Mr. Luos

Turn it over to the red part.

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:lmao:

Flush the radiator.

Is it over heating or is the temp. normal? If the tstat was stuck, you would most likely overheat or see an elevated temp. I'd start the car while cool, then take the radiator cap off while still cool, and as it warms up, you should see the fluid level slightly drop and see fluid pumping through radiator passages visible with the cap off. If after completely warm the water is barely moving, probably stuck tstat...if not circulating at all, maybe waterpump. Since tstat is cheap and a 5 minute replacement, I'd start there.

Take the cap off the radiator when it's cold and start it up. If the coolant immediately starts circulating then your t-stat is stuck open. I would look at that first then reverse flush the heater core if it's not the t-stat. I've ran into both situations in the last 2 months on different vehicles. Both have pretty much the same symptoms. The heat will get warm but not hot and takes a long time to get warm.

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Originally Posted by 0rion

Take the cap off the radiator when it's cold and start it up. If the coolant immediately starts circulating then your t-stat is stuck open. I would look at that first then reverse flush the heater core if it's not the t-stat. I've ran into both situations in the last 2 months on different vehicles. Both have pretty much the same symptoms. The heat will get warm but not hot and takes a long time to get warm.

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:yup:

crappy thing about the f body i syour gauge wont tell you if your car is running colder than normal.

Check the coolant/water level. No liquid no heat.

:lmao: no liquid= LOTS of heat :)

thanks, i'll have to report back after i do some testing tomorrow

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Originally Posted by 0rion

Take the cap off the radiator when it's cold and start it up. If the coolant immediately starts circulating then your t-stat is stuck open. I would look at that first then reverse flush the heater core if it's not the t-stat. I've ran into both situations in the last 2 months on different vehicles. Both have pretty much the same symptoms. The heat will get warm but not hot and takes a long time to get warm.

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i took of the cap, started the car and didn't see any liquid at all? am i really low on coolant? or is it so far down that it's too dark to see w/out a light?

There could be enough water to keep the engine from over heating but not enough to provide heat. I should have said the coolant level could be low and this will cause the heater not to put out any hot air.

I would definitely top it off. Sounds like you're just really low on coolant. Leave the cap off and keep topping it off until it's full and that'll purge any air out of the system. Make it a habit to start using the overflow reservoir and keeping an eye on it. That'll keep you from running so low.

i guess i have a slow leak. seems like every 6 months i have to top it off.

so do i pour into the radiator or the overflow tank?

I would pour it into the radiator until that's almost full and let the car come up to temp ( the level will rise as it comes up to temp), then let it run a bit to flush any air that might be in the system out ( 5-10 min), put the cap back on and let the car come completely up to temp, and fill the resevoir up to the "full when hot" mark.

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Originally Posted by Allen Wood

There could be enough water to keep the engine from over heating but not enough to provide heat. I should have said the coolant level could be low and this will cause the heater not to put out any hot air.

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i was just busting your chops.. it just came out funny and was too good to resist. :)

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Originally Posted by third_shift|studios

i guess i have a slow leak. seems like every 6 months i have to top it off.

so do i pour into the radiator or the overflow tank?

I would pour it into the radiator until that's almost full and let the car come up to temp ( the level will rise as it comes up to temp), then let it run a bit to flush any air that might be in the system out ( 5-10 min), put the cap back on and let the car come completely up to temp, and fill the resevoir up to the "full when hot" mark.

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Into the rad. and then just top off the over flow every couple weeks.

And last but NOT LEAST GO TO SKYLINE AND EAT 4 3-WAY FOR ME!!!!:chuckles:

Well, not sure what happened to my last post. It never showed up.:brick:

Fill the radiator almost full but leave a little room because the level will rise as the car heats up. After it runs a while and the coolant is circulating let it run a bit (5-10 min) to flush any air out that may be in there. Put the cap back on and let the car run a bit to get good and hot and fill your reservoir then.

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Originally Posted by LS2Tuner

Into the rad. and then just top off the over flow every couple weeks.

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that doesn't make any sense; to fill both the radiator AND the overflow?

What he's saying is to fill the radiator now then check back and top off the overflow every couple of weeks. What happens is that as the water gets hot and expands it's pushed into the overflow tank. That's why after this intial fill you fill at the overflow and only when the car is hot, so it doesn't push water out of the overflow.

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Originally Posted by 0rion

What he's saying is to fill the radiator now then check back and top off the overflow every couple of weeks. What happens is that as the water gets hot and expands it's pushed into the overflow tank. That's why after this intial fill you fill at the overflow and only when the car is hot, so it doesn't push water out of the overflow.

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Thank you Sir for explaining it in plain english.:cheers:

I had the same problem in my car, just needed to add some coolant and was pushing out hot air in no time. Did it fix your heat problem by doing that?

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Originally Posted by 0rion

What he's saying is to fill the radiator now then check back and top off the overflow every couple of weeks. What happens is that as the water gets hot and expands it's pushed into the overflow tank. That's why after this intial fill you fill at the overflow and only when the car is hot, so it doesn't push water out of the overflow.

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i know i'm making this harder than it needs to be...but by topping off both the radiator and the overflow, won't there be too much liquid in the sytem that could cause an explosino because of heat/expansion?

That's why your only toping off the rad. FIRST.
Then in a week or two top off the overflow IF NEEDED.

Now that the rad. is full you should be able to get away with only topping off the overflow.

Hope you got our point.

:thumbup: :hide: :sorry: :worship: :o thanks

No problem :cheers:Glad to help.:shots:
Now PLEASE don't forget my SKYLINE's this week!!!

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Originally Posted by LS2Tuner

Into the rad. and then just top off the over flow every couple weeks.

And last but NOT LEAST GO TO SKYLINE AND EAT 4 3-WAY FOR ME!!!!:chuckles:

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he is from pitt he does not like the chillie here, I on the other hand love it, and i shal eat it for you, lol:hyper:

thanks everyone! I put about a quart of 50/50 coolant into the radiator and took it for a spin...had some really bitchin heat after that. :thumbup:

would this kind of a diagnoses work for a 99 ford tauras? my fiance's car won't get hot inside until after about 30 minutes of driving, and then it's hardly warm.

I would say there is a 75% chance YES. Thank GOD I'm in AZ now don't have to worry about that anymore.:nana:

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Originally Posted by third_shift|studios

thanks everyone! I put about a quart of 50/50 coolant into the radiator and took it for a spin...had some really bitchin heat after that. :thumbup:

would this kind of a diagnoses work for a 99 ford tauras? my fiance's car won't get hot inside until after about 30 minutes of driving, and then it's hardly warm.

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I would say check her level but more times than not his ends up being a t-stat that's stuck open or less common a plugged heater core. Both are very easy and cheap fixes. Replacing a t-stat generally only takes a couple of minutes ( I tangled with a buick 3.8 a few weeks ago that was the exception) and is usually only a couple of bucks. Back flushing the heater core involves taking the hoses of to the core and back flushing it with a garden hose. It really sounds like an open t-stat to me though. Take her cap off and start the car and see if the coolant starts circulating immediately. That's a sign of a stuck t-stat.

thanks orion, i'll look into it tonight

ok, i saw she was low on coolant, almost a half gallon low, and when i started the car, i saw the coolant running. I guess it's a broken tstat. Is it worth dumping a bunch of coolant into her radiator or will it be worthless and all dump out when i replace the tstat

You shouldn't lose much at all doing the t-stat. Pay attention to the stat when you take it out. I've heard of people putting them in upside down. Personally on all the stats I've done I don't see how someone could make that mistake but I guess it happens.

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Originally Posted by third_shift|studios

ok, i saw she was low on coolant, almost a half gallon low, and when i started the car, i saw the coolant running. I guess it's a broken tstat. Is it worth dumping a bunch of coolant into her radiator or will it be worthless and all dump out when i replace the tstat

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It's been years since I worked on one of those. But if I remember correctly :think:they have a bypass/heater hose that runs in the top side of the rad. And if thats the case your going to see it circulate weather the t-stat is good or not.