No heat

[youstillmydog]

I have a 2002 lincoln ls 3.0 engine,it has no heat at all. Datc code is 1242, not sure if that code alone will stop the car from having heat. I felt the heater core pipes one was hotter than the other one and there was a larger pipe under the bottom. I unplug the connector from the heater control valve still nothing. I tried bleeding, I got a litter stream of water to flow from the heater bleed valve then it would stop for a second then another stream of water. But the stream that came though, was steady flow but not a continuously flow, not long enough to convince me that it was bled or that i was even doing it right. The little water that did come out of the heater bleed was hot though. No othe codes any ideas

[joegr]

No, B1242 is not the cause of you heating failure. It may not be a problem at all. It seems that it is not uncommon for various servo failure codes to be stored after a while. Usually, it means that the door (air inlet in this case) may have stuck briefly at some time but is probably okay now.

If you can't get a constant stream of water out of the bleed, then you have a leak and/or a clogged DCCV. You can have a pressure test of the cooling system done to see if you have a leak. If you do, it is probably the degas tank. They crack after a while. You probably need to replace it, replace the DCCV, and flush the cooling system and then bleed it.

[youstillmydog]

okay thanks i have a new dccv will install tommorow and see what happens will also flush the heater core

[joegr]

You need to flush the whole cooling system. The heater core's not where stuff clogs. The Tee in the upper radiator hose has a screen in it. This is one of the clog points.

[youstillmydog]

okay!! did as you suggested, flushed out entire system and replaced dccv. Now i have heat!!!!!!! But one last question. When I first turn the heat on the ac light comes on, so i just, mash the ac button to cut it off and then press which vent i want the heat to come threw. And it works fine. should that be a concern or not. Thanks in advance!!

[shorod]

How are you turning on the heat? If you are turning it on by pressing the "Auto" button, it is normal for the A/C to also turn on. If I recall correctly, per the manual the A/C defaults to on in pretty much all but one or two settings, unless you manually override it by pressing the A/C button.

-Rod

[joegr]

Originally Posted by youstillmydog

okay!! did as you suggested, flushed out entire system and replaced dccv. Now i have heat!!!!!!! But one last question. When I first turn the heat on the ac light comes on, so i just, mash the ac button to cut it off and then press which vent i want the heat to come threw. And it works fine. should that be a concern or not. Thanks in advance!!

Works as designed.

[youstillmydog]

okay, good deal then, I will call this a done deal, appreciate all the help

[danielsatur]

If your replacing the DCCV, you might consider a new thermo housing + thermostat kit.
Don't forget to back flush the heater core too.

[F4JetMech]

My 2001 Lincoln LS has NO heat. After reading numerous threads, I was able to troubleshoot and determine the following: no hot fluid exiting the DCCV, even after disconnecting connector to DCCV, no help. Inlet hose to DCCV from top of engine thermostat housing never gets hot. Also, lower radiator hose never gets warm either. No hot fluid entering or exiting DCCV. Ran on-board diagnostic of DATC, no fault codes displayed. Engine temp remains constant (guage mid-range), and does not over-heat. Also, I was able to get a steady HOT flow from the bleeder tube next to the degas bottle.Could this be the thermostat not opening, or will that have any effect on no hot fluid to the DCCV?

[joegr]

Originally Posted by F4JetMech

My 2001 Lincoln LS has NO heat. After reading numerous threads, I was able to troubleshoot and determine the following: no hot fluid exiting the DCCV, even after disconnecting connector to DCCV, no help. Inlet hose to DCCV from top of engine thermostat housing never gets hot. Also, lower radiator hose never gets warm either. No hot fluid entering or exiting DCCV. Ran on-board diagnostic of DATC, no fault codes displayed. Engine temp remains constant (guage mid-range), and does not over-heat. Also, I was able to get a steady HOT flow from the bleeder tube next to the degas bottle.Could this be the thermostat not opening, or will that have any effect on no hot fluid to the DCCV?

It sounds like your DCCV is stuck closed or clogged up. Either way, the solution is to replace it.

[shorod]

Not sure on this one, but it seems like if there is no flow through the DCCV, you may not have a hot heater hose going to the DCCV. The flow would circulate hot coolant. If there is no flow, there's little circulation, the only heat exchange would be through conduction and maybe a bit through radiation from the engine compartment.

I'd hate to suggest though that you replace the DCCV based on my hunch though....

-Rod

[F4JetMech]

Thanks for the response. It seems to me that if the DCCV was inop then the DATC self-test would flag it. I've let the engine run for up to an hour and the lower radiator hose never gets hot, nor does the intake hose to the DCCV. Any other ideas?

[joegr]

Originally Posted by F4JetMech

Thanks for the response. It seems to me that if the DCCV was inop then the DATC self-test would flag it. I've let the engine run for up to an hour and the lower radiator hose never gets hot, nor does the intake hose to the DCCV. Any other ideas?

The DATC self test can only test the electrical properties of the valves, and only some of those. The self test can detect if either of the solenoid coils are open, either are shorted to ground, or if either are shorted to battery. It can't test to see if there is any kind of mechanical problem such as the valves being stuck or clogged.

The lower radiator hose is the cooled water coming back from the radiator. If that hose ever got hot then it would be an indication that your radiator was clogged or your fan wasn't working. That hose is supposed to be cool.

[F4JetMech]

I guess that would seem to make sense, especially since the engine doesn't overheat. I suppose the next logical step would be to remove and disassemble the DCCV to see if it's clogged or if maybe the valves can be freed and salvaged.