Heater Issues - Got An Idea Need Advice

[dick0149]

here goes guys: my ac and heater stopped working the other day for no reason, i checked the fuses an coolant levels but no luck. i took it to jiffylube the other day to get oil change an other stuff. i asked the guy to look into the heating issue for me an he said he thought my heatercore was clogged to go to autozone an buy some prestone flush well i tried that 3 times an the guy at autozone said he had heard of people using draino an it worked safely.

anyways any recommendations?

[Tomj8]

here goes guys: my ac and heater stopped working the other day for no reason, i checked the fuses an coolant levels but no luck. i took it to jiffylube the other day to get oil change an other stuff. i asked the guy to look into the heating issue for me an he said he thought my heatercore was clogged to go to autozone an buy some prestone flush well i tried that 3 times an the guy at autozone said he had heard of people using draino an it worked safely.

anyways any recommendations?

No Draino!!! Not sure what causes the heater core to be suspect, but in general the symptoms don't fit. A heater core won't clog instantantly; you should have noticed a gradual and persistent loss of heating ability as the blockage built up if that were the problem. Does the fan still operate and the selected temperature still show up on the LCD display? If not, it may be the HVAC control module, if only the heat has dropped out, it may be the heater (hot water) control valve. Hard to say with certainty, but ditch the heater core idea unless there is some strong reason to think thats where the problem is. If the engine is running its making hot water. The other ingredients necessary to have a working heater are a heater core and hoses that allow the hot water to circulate, a working heater valve to control the temperature level, and a fan to move air across the heater core. No reason to suspect the HVAC if your LCD display is normal and the fan is working....that leaves the heater valve as the prime suspect since you've already flushed the system. Good luck - this isn't the season for heater problems!

[dick0149]

here goes guys: my ac and heater stopped working the other day for no reason, i checked the fuses an coolant levels but no luck. i took it to jiffylube the other day to get oil change an other stuff. i asked the guy to look into the heating issue for me an he said he thought my heatercore was clogged to go to autozone an buy some prestone flush well i tried that 3 times an the guy at autozone said he had heard of people using draino an it worked safely.

anyways any recommendations?

No Draino!!! Not sure what causes the heater core to be suspect, but in general the symptoms don't fit. A heater core won't clog instantantly; you should have noticed a gradual and persistent loss of heating ability as the blockage built up if that were the problem. Does the fan still operate and the selected temperature still show up on the LCD display? If not, it may be the HVAC control module, if only the heat has dropped out, it may be the heater (hot water) control valve. Hard to say with certainty, but ditch the heater core idea unless there is some strong reason to think thats where the problem is. If the engine is running its making hot water. The other ingredients necessary to have a working heater are a heater core and hoses that allow the hot water to circulate, a working heater valve to control the temperature level, and a fan to move air across the heater core. No reason to suspect the HVAC if your LCD display is normal and the fan is working....that leaves the heater valve as the prime suspect since you've already flushed the system. Good luck - this isn't the season for heater problems!

thank you for the help,

the heater was acting up from time to time here recently it would work but when i would stop or put it in park the heat would just stop working and blow cold air then this...

but my lcd screen works fine, the fan is working right.

so for the heater valve you know where it is so i can try replacing it an possibly good place to buy one

thank you once againm, and yeah i know i'm from south texas an stationed in missouri, so it gets pretty freakin cold up here

[DaveMcKenz]

here goes guys: my ac and heater stopped working the other day for no reason, i checked the fuses an coolant levels but no luck. i took it to jiffylube the other day to get oil change an other stuff. i asked the guy to look into the heating issue for me an he said he thought my heatercore was clogged to go to autozone an buy some prestone flush well i tried that 3 times an the guy at autozone said he had heard of people using draino an it worked safely.

anyways any recommendations?

No Draino!!! Not sure what causes the heater core to be suspect, but in general the symptoms don't fit. A heater core won't clog instantantly; you should have noticed a gradual and persistent loss of heating ability as the blockage built up if that were the problem. Does the fan still operate and the selected temperature still show up on the LCD display? If not, it may be the HVAC control module, if only the heat has dropped out, it may be the heater (hot water) control valve. Hard to say with certainty, but ditch the heater core idea unless there is some strong reason to think thats where the problem is. If the engine is running its making hot water. The other ingredients necessary to have a working heater are a heater core and hoses that allow the hot water to circulate, a working heater valve to control the temperature level, and a fan to move air across the heater core. No reason to suspect the HVAC if your LCD display is normal and the fan is working....that leaves the heater valve as the prime suspect since you've already flushed the system. Good luck - this isn't the season for heater problems!

thank you for the help,

the heater was acting up from time to time here recently it would work but when i would stop or put it in park the heat would just stop working and blow cold air then this...

but my lcd screen works fine, the fan is working right.

so for the heater valve you know where it is so i can try replacing it an possibly good place to buy one

thank you once againm, and yeah i know i'm from south texas an stationed in missouri, so it gets pretty freakin cold up here

Thermostat? Does your engine temp gauge reflect normal operating temps? Mine stuck in the open position and I got very little heat.

[BillyShaft]

Thermostat? Does your engine temp gauge reflect normal operating temps? Mine stuck in the open position and I got very little heat.

X2...

stuck open thermo + engine at idle = cold air blowing

[dick0149]

here goes guys: my ac and heater stopped working the other day for no reason, i checked the fuses an coolant levels but no luck. i took it to jiffylube the other day to get oil change an other stuff. i asked the guy to look into the heating issue for me an he said he thought my heatercore was clogged to go to autozone an buy some prestone flush well i tried that 3 times an the guy at autozone said he had heard of people using draino an it worked safely.

anyways any recommendations?

No Draino!!! Not sure what causes the heater core to be suspect, but in general the symptoms don't fit. A heater core won't clog instantantly; you should have noticed a gradual and persistent loss of heating ability as the blockage built up if that were the problem. Does the fan still operate and the selected temperature still show up on the LCD display? If not, it may be the HVAC control module, if only the heat has dropped out, it may be the heater (hot water) control valve. Hard to say with certainty, but ditch the heater core idea unless there is some strong reason to think thats where the problem is. If the engine is running its making hot water. The other ingredients necessary to have a working heater are a heater core and hoses that allow the hot water to circulate, a working heater valve to control the temperature level, and a fan to move air across the heater core. No reason to suspect the HVAC if your LCD display is normal and the fan is working....that leaves the heater valve as the prime suspect since you've already flushed the system. Good luck - this isn't the season for heater problems!

thank you for the help,

the heater was acting up from time to time here recently it would work but when i would stop or put it in park the heat would just stop working and blow cold air then this...

but my lcd screen works fine, the fan is working right.

so for the heater valve you know where it is so i can try replacing it an possibly good place to buy one

thank you once againm, and yeah i know i'm from south texas an stationed in missouri, so it gets pretty freakin cold up here

Thermostat? Does your engine temp gauge reflect normal operating temps? Mine stuck in the open position and I got very little heat.

thermostat goes to center like it's warmed up but no hot air

[eatingupblacktop]

Have you tried setting the vents to defrost and heat to max?

[dick0149]

yes i have. i recently drove up to the airport an back it took 4 hours an no heat still, half the time i had it on defrost with the a/c on cause the manual said it help get moisture out of the air

[eatingupblacktop]

Check the hoses at the firewall. If they are hot, then you have an issue with the heater valve, heater core, or cabin temp sensor.

[dick0149]

Check the hoses at the firewall. If they are hot, then you have an issue with the heater valve, heater core, or cabin temp sensor.

ok cool will do thanks

i know one of them is leaking coolant, but it is a very small leak would that possibly be a problem?

[eatingupblacktop]

Check the hoses at the firewall. If they are hot, then you have an issue with the heater valve, heater core, or cabin temp sensor.

ok cool will do thanks

i know one of them is leaking coolant, but it is a very small leak would that possibly be a problem?

The leak will not fix itself, so you will have to attend to it, but it is not the cause of your prob.

[dick0149]

ok the hose is getting hot so the prob has to be the heater control valve correct?

i had a friend who works on cars and he said the heatercore was fine

[eatingupblacktop]

ok the hose is getting hot so the prob has to be the heater control valve correct?

i had a friend who works on cars and he said the heatercore was fine

Well the valve is a lot easier to check/repair than the core.

[dick0149]

ok the hose is getting hot so the prob has to be the heater control valve correct?

i had a friend who works on cars and he said the heatercore was fine

Well the valve is a lot easier to check/repair than the core.

i'm sorry i don't know much about cars at all, but do you hapen to have any pics or how to's for troubleshooting it

[eatingupblacktop]

If you have track, then it's right behind the unit.

Here's a link with pics:

http://www.lexls.com/tutorials/EFI/throttlebody.html

In the second pic, flip the third arrow from the top and it will point to the valve.

In the fifth pic you can see where in enters through the firewall at the back.

Check that the cable hasn't siezed. If it's leaking at one of the hoses, check the clamps.

[dick0149]

new update i had the car inspected yesterday and the guy looked at my heater he said he is pretty sure that it's the heater core but it would cost around $2k for part and labor. i only owe about 2 on it so any suggestions?

[BillyShaft]

Well the valve is a lot easier to check/repair than the core.

umm...check this first?

Based on the commentary, the detailed photos, and the link to a how-to-check-this site, I suspect that this may be a common area of failure AND "a lot easier to check/repair than the core".

Or I guess you could skip the easy fixes and dive right into the remove-the-innards-of-your-car-and-hope-that-the-$2000-repair-actually-fixes-your-problem stage. All on the recommendation from a guy who is "pretty sure" that the core is bad? Pretty sure? You have got to be kidding, right?

What you want to hear from a real mechanic is something like this: "Sir, we have eliminated every other possible item in the heating circuit including a, b, c, x, y, and z. Unfortunately, the only possible thing it can be at this point is the core. I guarantee it."

[dick0149]

Well the valve is a lot easier to check/repair than the core.

umm...check this first?

Based on the commentary, the detailed photos, and the link to a how-to-check-this site, I suspect that this may be a common area of failure AND "a lot easier to check/repair than the core".

Or I guess you could skip the easy fixes and dive right into the remove-the-innards-of-your-car-and-hope-that-the-$2000-repair-actually-fixes-your-problem stage. All on the recommendation from a guy who is "pretty sure" that the core is bad? Pretty sure? You have got to be kidding, right?

What you want to hear from a real mechanic is something like this: "Sir, we have eliminated every other possible item in the heating circuit including a, b, c, x, y, and z. Unfortunately, the only possible thing it can be at this point is the core. I guarantee it."

yeah i get what your saying, what had happened is he was just looking at it, he wasn't like going deep into it cause i just asked for some advice i wasn't paying him to tel me the prob.

but i am going to try and replace the heater control valve an see what happens there, if i do end up getting rid of it i found another 93 sc4 in houston that is really clean for $6k.

thanks so much to all of you

[slade228]

I can occasionally get heat on my 93 sc400....reading past posts It might be solonoid valve that opens heat valve...I cannot locate this part..can someone give me a more accurate description to where it is and looks like..thx jimmy ny

[dick0149]

I can occasionally get heat on my 93 sc400....reading past posts It might be solonoid valve that opens heat valve...I cannot locate this part..can someone give me a more accurate description to where it is and looks like..thx jimmy ny

i think i might have read that awhle ago, good thought