No heat, help

NEON PARABOLA · Post by **NEON PARABOLA** » Mon Oct 22, 2012 12:18 pm

Just replaced the water pump, both radiator hoses, thermostat and thermostat cap. I get hot air for a second, than it goes ambient or cold air. Where exactly are the lines for the heater core? is there a half way convenient place to simply flip them around and see if that helps?

Need any and all advice, I'm not willing to rip my dash apart

NEON PARABOLA · Post by **NEON PARABOLA** » Mon Oct 22, 2012 1:34 pm

quick update:
found the lines, both are geting hot. I am going to try flipping them tonight and see if that does anything

Post by **occasional demons** » Mon Oct 22, 2012 1:34 pm

The rubber hoses attach at the end of the cylinder head, and go to the fire wall by the brake booster. Check the hoses there if they both are hot, you don't have a circulation problem.

You probably have an air blend door issue. The door blocks the flow through the heater core, when no heat is desired, and opens when you need it. You may have to pull the HVAC bezel, and the HVAC control module to check to see if all the cables are intact/connected. Not sure if you can see the HVAC module end of it without further disassembly.

If both/one is cold, then you need to loop the lines, and replace the heater core. The engine needs the flow to keep the internal coolant circulation when the t'stat is shut.

If the lines need looped at the cylinder head, you will need to buy a pre-bent u bend hose, or regular hose will just kink, and shut off the flow.

The rubber hoses that connect to the metal hard lines could also be blocked internally. Or the hard lines themselves. Pray those are in good shape.

If the coolant is low, you will also get no heat.

Post by **occasional demons** » Mon Oct 22, 2012 1:36 pm

NEON PARABOLA wrote:quick update:
found the lines, both are geting hot. I am going to try flipping them tonight and see if that does anything

Probably the air blend door. :/

Flipping them won't really help.

These cables may not be connected anymore, or the door itself is screwed.

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NEON PARABOLA · Post by **NEON PARABOLA** » Mon Oct 22, 2012 2:14 pm

how would you explain some heat than no heat then? if the door was broken wouldnt you get no heat at all?

Post by **occasional demons** » Mon Oct 22, 2012 9:46 pm

The air flow could be blowing it shut? If the coolant is flowing through the core, ie both hoses hot, then the core is hot. It won't go cold in a few seconds, maybe a minute or so, if the flow was suddenly cut off.

But as long as both hoses are hot, there is some flow. If it was clogged you would have engine temp issues too. The coolant in the head would get hot very quickly, as it would not be moving.

If you remove the cable from the controls, you should be able to push/pull it quickly, and hear the air blend door move, or feel the resistance of it moving. If the cable has absolutely no resistance, it has come off the door lever, or the lever has broken.

NEON PARABOLA · Post by **NEON PARABOLA** » Tue Oct 23, 2012 8:42 am

Good to know,
Last night I disconnected both hoses and flushed the core out multiple times in both directions, and filled it with new coolant. I have some heat now, and the engine seems to take allot longer to heat up now (about 10 mins of slow driving vs 5 minutes) I am going to flush it again, but with CLR to break up any more sediment, and then flip the lines for a week or so. Than i will flush the entire system. we shal see

lilnicko11 · Post by **lilnicko11** » Tue Oct 23, 2012 10:30 am

wow what a pic of everything ripped apart. scary kinda.

NEON PARABOLA · Post by **NEON PARABOLA** » Tue Oct 23, 2012 10:32 am

the previous owner filled the cooling system with water only,so allot of bends are full of rust particles. I got about half a handful of "black sand" out of the core by filling it with water and blowing it out

NEON PARABOLA · Post by **NEON PARABOLA** » Wed Oct 24, 2012 9:35 am

fliped the lines and now I have heat. the engine seems to take quite a while to get up to operating temp.

NickKo · Post by **NickKo** » Thu Oct 25, 2012 7:39 am

NEON PARABOLA wrote: the engine seems to take quite a while to get up to operating temp.

Seems like your cooling system needs a 'POWER BACKFLUSH'.

A good radiator shop can do this.
With a power backflush, the radiator shop will power-flush the cooling system 'backwards'..... This will remove all kinds of crud, that a 'regular' flush, simply can't do.

I have noticed that after running a power back-flush, the engine runs both cooler in summer..... and the temp gauge runs hotter in winter - making the heater much more effective !!
Definitely worth the money.

- Nick

NEON PARABOLA · Post by **NEON PARABOLA** » Thu Oct 25, 2012 9:04 am

OOOHHHH

thanks for the info nick,I will definitely get this done!