Does this sound like a failed DCCV

[LSC_YA]

It started out as heat on one side a/c on other. Then you would have to turn temp all the way down and back up to get heat. Now you very seldom if ever get heat. It was a little warmer at interstate speed or if you rev it up some times, but not now. No air in system it has been bled and is full of coolant. Sound like DCCV ?

 

[NYC LS8]

Sounds more like the DCCV.

 

[joegr]

DCCV normally fail in the full heat position. Yours may just be clogged. The coolant should be flushed every three years. If you haven't been doing that, that may explain it. The DCCV may just need to be cleaned after flushing the coolant. Also, are you sure there is no air in the cooling system? Your degas bottle and other plastic parts may be cracked.

 

[LSC_YA]

What is the best way to flush the system. When you flush the system will it flush the DCCV. If not Is there a way to flush the DCCV without removal. thanks

 

[joegr]

What is the best way to flush the system. When you flush the system will it flush the DCCV. If not Is there a way to flush the DCCV without removal. thanks

I suspect that you will have to remove and clean it, but it won't hurt to just try the flush first. I've gotten kind of lazy on some things, so I just let the dealership do it with there flush machine.

You can buy some garden hose adapter kits that tap into heater hoses, but those have at least two problems. One, they won't flush all the coolant flow loops, and two, you can easily over pressure the cooling system and cause the water pump to fail, the DCCV to be damaged, and so on.

If you search, there are some good posts on dis-assembly and cleaning of the DCCV, with pictures even.

 

[tireman]

past one year cleaning!

I took my DCCV off and cleaned it completely. Put it back in. Been running fine for just over one year now. Never hurts to flush the system out of all the debris that can jamb the DCCV pistons.

 

[FASTLLS]

^
+1

Especially if you haven't flushed the system in awhile..

 

[scjmc]

Sounds like DCCV to me too. I am on my third one and I always keep my coolant flushed. When failing I could usually get it to work by working the temp up and down like you described. Eventually it crapped out completely at full heat on passanger side and full cold on driver's side -both times-.