joegr ....heat question

[joespanova]

I installed 2 cutoff valves to get around a faulty DCCV ( for AC ). Worked great all summer but now the heat won't blow hot when valves are opened. DCCV solenoids stuck in closed position? The hoses seem warm enough so I'm not sure. Clogged core...I doubt. Any clue. I think I have to bypass DCCV completely , which I haven't done. AC and heat will just have to be regulated by fan speed.....lol.

 

[Linc615]

After owning both gens I’ll throw my 2 cents in on this. Cutoff valves was first mistake, the car has finicky cooling system. It needs every inch of cooling hose and capacity available to not damage anything not seen to the naked eye, if you pull up the routing of the entire cooling system flow schematic no matter what that dccv is is full force dependent on if the engine is running, even when it is off it’s still being used by way of the secondary water pump. I would think with cutoff valves it sent a lot of fluid to the dccv and aux water pump to sit there stagnant with no where to go and as well as in the heater core increasing the rapid growth of coolant material bc it’s not flowing or getting hot it’s no chance to kill it.

Heater core prob needs a backflush, and a lot will disagree but I’ve found aluminum acid cleans the f out of the coolant system. I’ve done it on my LS’s as well as my 2016 MKZ 3.7L and I’m at 240k as a daily driver of 300 commuting miles a day most days. I’ve had no issues doing so except a cooling system that works no matter what even with an internal water pump.

I don’t recommend it I also don’t disapprove it take that with a grain of salt and decide what you think is best for your situation.

I would never recommend aftermarket eBay dccv, it’s rare you get one worth a shit, but I would recommend it as apposed to a shutoff valve on the system. Any day. You will change them a lot bc they don’t last long but it’s better than your current setup.

The plug also gets wet its in a bad location OEM. Take dccv out and clean the little motors gently it involves disassembly of dccv, that could bring it back to life. Clean water out of plug if it’s standing inside. Hooking an alligator clip to it with 12v battery will confirm operation before reinstallation.

If you have a gen 1 after you upgrade to electric fan that pump gone opens up a lot of room, I relocated my dccv up there which made it last longer bc it wasnt sitting under any kind of fluid droppage. This takes extra hoses but you seem to know basic car plumbing and it shouldn’t be an issue.

Careful back flushing core, it’s likely eaten thru it if it’s been not circulating which is probably ten times the cost of a dccv to fix that issue. I hope this helps and good luck with what you decide and keep us updated I’m curious how it turns out myself

 

[joespanova]

After owning both gens I’ll throw my 2 cents in on this. Cutoff valves was first mistake, the car has finicky cooling system. It needs every inch of cooling hose and capacity available to not damage anything not seen to the naked eye, if you pull up the routing of the entire cooling system flow schematic no matter what that dccv is is full force dependent on if the engine is running, even when it is off it’s still being used by way of the secondary water pump. I would think with cutoff valves it sent a lot of fluid to the dccv and aux water pump to sit there stagnant with no where to go and as well as in the heater core increasing the rapid growth of coolant material bc it’s not flowing or getting hot it’s no chance to kill it.

Heater core prob needs a backflush, and a lot will disagree but I’ve found aluminum acid cleans the f out of the coolant system. I’ve done it on my LS’s as well as my 2016 MKZ 3.7L and I’m at 240k as a daily driver of 300 commuting miles a day most days. I’ve had no issues doing so except a cooling system that works no matter what even with an internal water pump.

I don’t recommend it I also don’t disapprove it take that with a grain of salt and decide what you think is best for your situation.

I would never recommend aftermarket eBay dccv, it’s rare you get one worth a shit, but I would recommend it as apposed to a shutoff valve on the system. Any day. You will change them a lot bc they don’t last long but it’s better than your current setup.

The plug also gets wet its in a bad location OEM. Take dccv out and clean the little motors gently it involves disassembly of dccv, that could bring it back to life. Clean water out of plug if it’s standing inside. Hooking an alligator clip to it with 12v battery will confirm operation before reinstallation.

If you have a gen 1 after you upgrade to electric fan that pump gone opens up a lot of room, I relocated my dccv up there which made it last longer bc it wasnt sitting under any kind of fluid droppage. This takes extra hoses but you seem to know basic car plumbing and it shouldn’t be an issue.

Careful back flushing core, it’s likely eaten thru it if it’s been not circulating which is probably ten times the cost of a dccv to fix that issue. I hope this helps and good luck with what you decide and keep us updated I’m curious how it turns out myself

That DCCV is a royal PITA to get to on the Gen1. My consideration to relocate was "on the table" but as of yet , no. Adding an electric fan and removing aux pump as you have determined opens up some room , but , that hasn't been considered because mine never runs hot , so if it ain't broke I'm not making more work for myself. I'll look at that though. In the summer the valves are closed ANYWAY so not sure what you're suggesting about dead head flow issues with aux pump. Seems to me it would be the same thing. Removing the valve completely and going old school minus "blend " doors ( yes I know the LS has none ) means I'd have to manually cut heat in the summer ( with valves ) and regulate cabin temps with fan speed ( or just turn off ( AC ).

 

[joespanova]

BTW the cutoff valves are AFTER the DCCV.

 

[joespanova]

joegr nothing from you......I assumed you were a part of the admin team. Guess not. Its interesting that no one suggested the aux water pump failure as a possible problem with low heat output. If the return through the DCCV goes also thru the aux pump , it seems to me the inop pump would inhibit water return , or even stop it. No flow , no heat. So in summary 2 things......stuck or inop DCCV or aux pump.....or both.

 

[04_Sport_LS]

joegr nothing from you......I assumed you were a part of the admin team.

I would say Joe is pretty much retired from LVC. What more could he add at this point? And you would hear the aux pump run for a few seconds after shutdown if functioning properly... depending on ambient temps.

 

[sowberry]

I would say Joe is pretty much retired from LVC. What more could he add at this point?

Man, that's sad to hear. I'd guess joegr was getting up there in years, but it seemed like this forum was something that he enjoyed. I for one really appreciated being able to rely getting actual expert advice from him here (as opposed to most of the internet). I hope he's still kicking but just doesn't feel like spending time online anymore. God bless him.

Anyways, been a couple years since I checked in here. I ended up in this thread because my heat has gone out ('02 V6). I replaced my DCCV a couple years ago to try to fix lack of A/C. Although I bought supposed Motorcraft (I think on eBay), it didn't fix the A/C. Didn't bother me too much, but now lack of heat hurts more here in Chicago.

My DATC self-test says intake door or something is bad (forget the actual code), but nothing about the DCCV. It does seem like it's taking longer for engine temp to come up to normal. Maybe thermostat is stuck open? Even if so, shouldn't I get heat after engine is warm? Sometimes the heat will come on after an hour or so. Maybe heater core is partially plugged? Can anyone offer some troubleshooting recommendations?